Grant A. Harris Fellowship
Past Recipients

MCMASTER UNIVERSITY

Award: TEROS soil moisture sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Fire weather controls and thresholds to peat smoldering vulnerability in natural and managed boreal peatlands

UTAH STATE UNIVERSITY

Award: HYPROP and KSAT laboratory hydrology instrumentation

Topic: Designing and characterizing hydraulic properties of rooted plant growth substrates for reduced gravity applications using state-of-the-art measurements

UNIVERSITY OF VIRGINIA

Award: TEROS soil moisture sensors, ATMOS 41 weather stations, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Modeling permafrost and seasonally frozen ground temperature profiles in the Himalayas

STANFORD UNIVERSITY

Award: TEROS soil moisture sensors, ATMOS 41 weather stations, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Protecting rice from coupled climate and soil contamination threats

THE UNIVERSITY OF NORTH CAROLINA

Award: HYDROS water depth sensors, TEROS soil moisture sensors, ATMOS 41 weather stations, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Frost action mitigation in granular roads through engineered water repellency at MnROAD

MICHIGAN STATE UNIVERSITY

Award: HYPROP laboratory hydrology instrumentation

Topic: Towards understanding the impacts of ground-mounted solar installations on local hydrology and soil conditions

IDAHO STATE UNIVERSITY

Award: TEROS soil moisture sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Investigating long-term water storage in trees and its importance for whole-tree water relations

UNIVERSITY OF FLORIDA

Award: TEROS soil moisture sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Roots of change: blueberry production for a changing climate

UNIVERSITY OF MISSISSIPPI

Award: TEROS soil moisture sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Modeling the influence of hydraulic properties of natural soils on their acoustic responses for landmine detection

YALE UNIVERSITY

Award: PHYTOS 31 leaf wetness sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Examining the Interactive Effects of Climate Change and Grazing on the Stability of Big Sagebrush Plant Communities

OREGON STATE UNIVERSITY

Award: TEROS soil moisture sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Developing a Crop Water Stress Index for Red Maple

OREGON STATE UNIVERSITY

Award: ATMOS 41 all-in-one weather stations, ZL6 data loggers and subscriptions to ZENTRA Cloud

Topic: Vertical microclimate variability and bird occupancy in temperate forests

UNIVERSITY OF NEW MEXICO

Award: PAR (photosynthetically active radiation) sensors, HYDROS 21 water-level monitoring sensors, ZL6 data loggers and subscriptions to ZENTRA Cloud

UNDERSTANDING SOLUTE TRANSPORT THROUGH EULERIAN AND LAGRANGIAN MONITORING

Solute transport research within fluvial systems has led to considerable advances in our fundamental understanding of surface to groundwater interactions, flow paths, residence times, and zones or conditions of optimal solute biochemical reactivity.  For example, past solute monitoring programs have quantified 956,500 tons per year of anthropogenic nitrate loads within the Mississippi which drives yearly eutrophication in the Gulf of Mexico (Val et al, 2006; Heisler et at., 2008; Sobota et al., 2015).

While there has been great insight gained from past research, they have primarily utilized Eulerian sampling regimes and has often been confined to surface waters. Such sampling methods often do not address the spatial heterogeneity that is inherently present in watersheds (Blaen et al., 2016; Krause et al., 2017). Therefore, we purpose integrating METER’s HYDROS 21 sensor with the novel Navigator, a floating multiparameter sonde, to be able to utilize Lagrangian approaches to track solutes, quantity diffuse and point sources, and identify areas of accelerated processing within fluvial systems. We would also deploy Hydros 21 sensors at shallow to deep depths within the hyporheic zone adjacent to pre-existing surface water quality sondes to quantify ground to surface water flux during Navigator field experiments (Boano et al., 2014). By coupling Lagrangian, Eulerian, and surface to groundwater monitoring, we aim to address the uncertainties associated with watershed heterogeneity and the resultant effect on solute transport.

UNIVERSITY OF WYOMING

Award: ATMOS 22 ultrasonic anemometers, TEROS 11 soil moisture and temperature sensors, and ATMOS 14 four-in-one temperature/RH/barometric pressure/vapor pressure stations.

MODELING WATER/NUTRIENT CYCLING AND YIELD FOR A PERENNIAL GRAIN

Kernza®, the first perennial grain crop ever developed, has the potential to revitalize agriculture in the High Plains, yet it is unknown how this novel crop will adapt to such a dry environment. Under a University of Wyoming (UW) funded project, Kernza will be planted on seven farms in eastern Wyoming in in order to study its long-term profitability, sustainability, and effects on soil health, nutrient cycling, and water availability. This grant will contribute to that project by enabling us to measure soil conditions and microclimate in Kernza, annual wheat, and restored prairie fields for three years.

We will confront a first principles, biophysical model, the Terrestrial Regional Ecosystem Exchange Simulator (TREES), with data from Kernza and wheat to improve predictive understanding of how differences in water and nutrient usages affect their long-term viability. The biophysical approach is especially well suited to test our hypotheses that tight nutrient cycling and deep perennial roots will enable Kernza to succeed as a sustainable crop in eastern Wyoming and the High Plains ecoregion. We will collaborate with farmers to enable them to make science-informed decisions about using Kernza to replace wheat.

UNIVERSITY OF ARIZONA

Award:  TEROS 12 soil moisture, temperature and electrical conductivity sensors and ZL6 data loggers

USING AGRIVOLTAICS TO CREATE FOOD, ENERGY AND WATER SUSTAINABILITY IN A CHANGING WORLD

We have significant vulnerabilities across our food, water and energy systems being stressed by population growth and climate change. Here, we explore a hybrid agricultural-photovoltaic (PV) ‘agrivoltaics’ solution. We are creating the largest agrivoltaics site in the US – a 1.2 MW, 6-acre community solar farm in Longmont, Colorado called Jack’s Solar Garden. The farmer will grow crops for market while producing PV energy, and he has invited our team to study diverse aspects of agrivoltaics.

Specifically, our team plans to study the optimization of crop growth and irrigation use through precision monitoring of soil moisture and electrical conductivity and plant photosynthesis, biomass and yield. We will be work alongside partners at the National Renewable Energy Laboratory, Colorado State University, Audubon Rockies, Sprouts City Farms and local government. Public farm tours, commencing spring 2021, will take
a path through our group’s research area, providing direct exposure to the science. Agrivoltaics is a novel means to adapt to and mitigate climate change, and we hope to continue leading the scientific discoveries driving this field.

UNIVERSITY OF CALIFORNIA

Award: HYPROP 2 soil moisture release curve instrumentation

SOIL WATER RETENTION CURVE HOLDS THE KEY FOR UNDERSTANDING SOIL C DYNAMICS UNDER VARIABLE MOISTURE AND TEMPERATURE CONDITIONS

The reduction of our atmospheric carbon (C) emissions is arguably one of the most pressing problems we face globally. It has resulted in unstable climatic conditions causing the loss of vital resources and disrupting societies. Soils regulate by storing C and can turn from massive sinks to significant C sources when the rate of C mineralization exceeds C inputs. Thus, understanding C mineralization rates’ primary drivers is imperative to developing accurate models that aid in climate change mitigation and adaptation plans. The soil’s physical environment is particularly critical in regulating C mineralization rate, but it remains poorly understood [4].

This proposed research aims to provide a quantitative link between the spatio-temporal variability of soil water and temperature with microbial respiration rate. Specifically, we aim to develop novel measurement techniques to explain how soil structure influences the coupling between hydrological, thermal, and biogeochemical processes.

OREGON STATE UNIVERSITY

Award: PHYTOS 31 leaf wetness sensors, IRT infrared thermometers, ATMOS 41 weather stations, TEROS 21 matric potential sensors and ZL6 data loggers

PREDICTING DROUGHT VULNERABILITY ACROSS A MOUNTAIN LANDSCAPE: CONNECTING DEWFALL, LEAF WATER UPTAKE AND SOIL WATER TO DROUGHT STRESS IN OLD GROWTH FORESTS

The welfare of plant and animal species that inhabit old growth forests in the Pacific Northwest is inextricably linked to the welfare of tall trees. Tall trees create microclimate refugia and redistribute deep soil water to the surface during the summer dry season, when water and heat stress increase and fire risk intensifies. During these periods, access (or lack thereof) to deep soil water can have a large impact on tree moisture stress, and the delivery of moisture to the canopy by overnight dewfall events not only ameliorates drought stress through foliar absorption of water but helps to maintain microclimate refugia via evaporative cooling , modulates fire risk from fuels drying, and sustains epiphyte water and carbon balances.

Layered on these realities is a growing body of evidence which suggests unmanaged, older forests are more resilient to forest fire than managed plantations. Taken together, it is clear that management plans which aim to maximize forest resilience and ecosystems services need to consider patterns of vulnerability of old growth treesto changing climate.

Recent work at the H.J. Andrews experimental forest using PHYTOS 31 sensors has shown that the top (56m height) of the Discovery Tree, an old growth Douglas-fir growing at 450m elevation in a narrow valley, received dewfall on ~30% of summer nights, a pattern which was poorly captured using the traditional Penman approach, even with co-located met data (Fig. 1), illustrating the great utility of the leaf wetness sensor data. We also conducted a dew wetting experiment in late August 2020 on the Discovery Tree which showed uptake of sprayed water by the tree’s needles, though the uptake did not greatly affect needle tissue water relations as the studied tree was not experiencing undue water stress. This is likely because of the tree’s position on the alluvial plateau of a perennial stream – old growth stands at higher elevations with greater exposure to drier air of the lower troposphere and rooted in rockier soils may well have been experiencing significantly greater moisture stress at the time of our experiment. However, it is not obvious whether these factors could be offset by generally cooler summertime maximum temperatures or the persistence of snowpack late into the spring at higher elevations, and merits further investigation.

Our proposed research would create a network of METER sensors in strategic positions across our mountainous study area that together with summer field campaigns would allow us to quantify how differences in dew frequency, leaf water uptake, and soil moisture deficits culminate in different levels of drought stress across the landscape.

UNIVERSITY OF ARIZONA

Award: PHYTOS 31 (5) leaf wetness sensors and ATMOS 41 all-in-one weather stations

UNDERSTANDING HOW CLIMATE CHANGE CAN IMPACT THE AMAZON FOREST WATER CYCLE BY USING METER SENSORS TO REVEAL DRIVERS OF BRANCH-LEVEL WATER FLUXES

Tropical forests cycle more carbon and water than any other terrestrial ecosystem.Current research has not adequately addressed how microclimate and biology interact to determine the energy partitioning between latent heat flux (LHF, i.e. evapotranspiration) and sensible heat flux (SHF, i.e. convective heat) within forest canopies. This is key to understanding and predicting the future direction and magnitude of water fluxes in tropical forests under climate change. METER’s ATMOS-41 and PHYTOS-31 sensors will allow me to create a unique long-term dataset of branch-level leaf traits, wetness, temperature, and microclimate. This dataset will show how the leaf energy budget is affected by microclimate, and how microclimate effects change in leaf energy budget across gradients of canopy height and light.

UNIVERSITY OF SOUTH CAROLINA

Award:  NDVI and PRI SRS sensors, ZL6 data logger and ZENTRA Cloud

QUANTIFYING SEASONAL VEGETATION CONTROLS ON COASTAL DUNE VOLUMETRIC CHANGE

Coastal dunes—located on the subaerial beach—provide a formidable barrier to storm surge and flooding that protect coastal communities from economic loss. Vegetation-sediment interactions mark a keystone component to understand coastal dune growth and post-storm recovery. Notwithstanding this importance, traditional methods of monitoring vegetation have resulted in data inconsistencies and qualitative assumptions. The year-long field study proposed here will use NDVI and PRI SRS sensors to spectrally monitor dune vegetation concurrently with in situ digital erosion pins (DEPs). For the first time vegetation and erosion-accretion dynamics will be measured at the same sampling resolution, marking a momentous advancement in coastal geomorphology.

The interplay of wind, sediment, and vegetation sculpt dune features via aeolian (wind- blown) processes (Sherman, 1995). Vegetation induces turbulence into the wind field disturbing sediment transport, and often, facilitating deposition and dune growth (Hesp, 1981). Traditional methods for assessing dune vegetation has either relied on qualitative estimation of vegetation quadrats (Stalter, 1974; Kim and Yu, 2009) or solely captured spatial properties of vegetation density via photographs (Gillies et al., 2002; Renkin, 2015). These methods make it difficult to develop a continuous time series of vegetation data, and often leaves researchers with temporal snapshots of vegetation variability.

The primary objective of this study is to quantify the influence seasonal vegetation density and health has on dune volumetric change. 

This study will introduce a new methodology to coastal geomorphology using NDVI and PRI SRS sensors to quantify vegetation density and stress. The creation of a continuous vegetation dataset paired with in situ erosion-accretion measurements will aid in understanding vegetation-sediment interconnectedness and dune formation.

VIRGINIA TECH

Award:  SATURO infiltrometer, TEROS soil moisture sensors, ECRN-100 rain gauge, ZL6 data logger and ZENTRA Cloud

PAUSING PRECIPITATION: INNOVATIVE METHODS TO LIMIT RAIN INFILTRATION INTO VINEYARD SOILS

The wine industry in Virginia often suffers from excess soil water availability, which can negatively impact wine quality. We propose to use METER instruments to test several infiltration-reducing compounds for their ability to reduce the amount of water entering vineyard soils. Limiting infiltration should improve grapevine growth and fruit quality for winemaking, and could transform grape growing in high-precipitation winemaking regions of the world.

Significance of Research: As of 2015, Virginia was #8 in the United States for vineyard hectarage, and had an economic impact of $1.37 billion.

1 Virginia receives an average of 108.4 cm of precipitation annually, with the highest rainfall during the months of May, July, and August.

2 This high rainfall translates to excess water availability in many Virginia vineyard soils which can produce vigorous vine growth (e.g., destabilize the balance of vegetative growth to crop development) and be detrimental to fruit quality. Winegrape quality is positively impacted when mild water deficits limit vine growth, especially in wet climates such as Virginia. Grape growers in this region are eager to reduce soil water, especially during excessively wet years, and there are no economical and sustainable methods currently available.

Many strategies have been tested to reduce vineyard soil water such as tile drainage, cover crops (to compete for water), and plastic soil covers. However, these interventions all have limitations ranging from high costs of tile drain installation to the often-negligible net water use by cover crops to the negative environmental impacts of plastic waste. Compacting soils to limit rain infiltration has also been proposed, but could prevent evaporation from soil and may create issues with drainage, root respiration/gas exchange, and erosion.

Goals & Objectives: The ideal vineyard soil water intervention would limit infiltration into the soil while minimizing erosion and allowing vapor and gas exchange. To achieve this ideal intervention, we propose to test several environmentally-friendly polymeric compounds developed by the transportation industry to decrease infiltration into soil: DirtGlue (Salem NH) and Soiltac (Soilworks, Scottsdale AZ). We will also test stearic acid, a naturally occurring hydrophobic fatty acid, which can reduce infiltration while enhancing water vapor losses from soil.4 Such compounds have not been tested as a way to control soil water within vineyards. Our goal is to compare the effectiveness of soil-applied compounds for reducing infiltration into soils, then quantify the impacts on grapevine growth and fruit quality.

UNIVERSITY OF CALIFORNIA, SANTA CRUZ

Award: TEMPOS thermal properties analyzer, SC-1 leaf porometer, TEROS 21 water potential sensors, TEROS 10 soil moisture sensors, ZL6 data logger and ZENTRA Cloud.

IS UNDERGROUND WATER STORAGE A KEY TO JOSHUA TREE SURVIVAL?

The Joshua tree, an icon of the American West, is threatened by climate change. While some aspects of Joshua trees have been well-studied, we have a limited understanding of their water management under periods of extreme water stress. The objectives of this research are to

1) evaluate the role of water storage in Joshua tree water budgets,

2) document the yearly fluctuations in water storage in the tissues of Joshua trees, and

3) develop an integrated model of Joshua tree anatomy and water relations to simulate whole-plant hydraulic responses to different climate conditions.

These data can be used to model future Joshua tree distributions, inform conservation planning and assisted migration efforts, and improve our understanding of ecohydrology in the Mojave Desert.

The Joshua tree is a charismatic species and a vital economic force attracting visitors to its popular namesake national park. It is also a foundational species that provides services to Mojave Desert ecosystems. Climate change is expected to reduce Joshua trees to 10% of their current range due to increased temperatures and more frequent drought1. Although much is known about the natural history of Joshua trees, we do not know much about their water budgets. Understanding water storage and its fluctuations in Joshua trees, both on daily and annual scales, will give us new knowledge about how they may respond to individual and successive droughts.

Initial Results: Observations and microCT of Joshua tree roots and a drought study imply that water storage does not occur in the stem as expected, and may occur in specialized root tissues.

Hypotheses: (H1): Joshua tree tissue water content, water potential, and transpiration will fluctuate daily and annually in a manner that reflects their usage of both soil water and plant water storage. (H2): The transpiration of Joshua trees includes water that was stored in speicalized tissues in the roots. (H3): Joshua trees will require several precipitation pulses following long periods of dry conditions to replenish water in storage tissues to full capacity.

TEXAS A&M UNIVERSITY

Award: SC-1 leaf porometers, PAR sensors, a ZL6 data logger and ZENTRA Cloud

INVESTIGATING THE RELATIONSHIP BETWEEN PLANT PRIMING AND STOMATAL CONDUCTANCE

Herbivores often invade agricultural fields and can lead to devastating yield losses. Following an attack, plants emit characteristic blends of herbivore-induced plant volatiles (HIPVs), which play important roles in plant defense. Recently, it has been discovered that plants also perceive and respond to HIPVs. Some plants detect HIPVs emitted by their damaged neighbors and respond by enhancing their own defenses in preparation of future attack, known as priming. Defense priming has been documented in a wide range of plant species, including several agriculturally important crops like maize and cotton. However, little attention has been given to the physiological basis of this process.

In general, plant gas exchange occurs through stomata, and calculations indicate that volatile compounds can enter the plant through stomates in light conditions4. Two major unanswered questions in plant defense priming are:

1) how do plants take up volatile compounds for priming? 

2) how does plant exposure to volatile compounds influence physiological processes like gas exchange?

No previous research has considered the physiological implications of plant defense priming. Improving our understanding of plant responses could reveal new strategies for enhancing plant resistance to pests.

Goals and Objectives

The goal of this project is to use the SC-1 Leaf Porometer to

1) determine if stomatal openings are required for plant priming by HIPVs and

2) determine whether plant priming via HIPVs influences stomatal conductance. We predict that HIPVs enter plant leaves through stomates and that successful priming will be positively correlated with stomatal conductance.

Additionally, if priming cues are taken up through stomata, plants might increase stomatal conductance to increase their access to information while on high alert. Previous work from our lab found a positive correlation between priming and exposure dose5. Further, since plant investment in defenses requires carbon stores and energy, we also predict that plant exposure to HIPVs influences regulation of stomatal conductance to enhance plant gas exchange and photosynthesis.

UTAH STATE UNIVERSITY

Award: PARIO soil texture analyzer and a WP4C water potential lab instrument

SOIL GENESIS ACROSS A CLIMO-LITHOSEQUENCE OF WESTERN HALEAKALĀ

There is enormous climate variability (200 to >2000 mm in precipitation) and soil diversity (seven soil orders of Soil Taxonomy) on the northern and western slopes of Haleakala volcano on the Hawaiian island of Maui. This little studied area provides an ideal location to investigate the influence of climate and volcanic ash on soil development on basalt lava flows. In addition, as land use on Maui shifts from monocultures of sugarcane to livestock grazing and ecotourism, there is growing interest in sequestering soil carbon and developing markets for niche specialty crops. Sampling sites (19) were selected based on similar geology and relief, and were manually excavated, described, and sampled by genetic horizon for a full suite of laboratory analyses. We expect high variability in nutrient and water holding capacity, elemental loss, and carbon content due to the presence of cinder cones across the study site. Findings will help determine the distribution of these ash-influenced soils, and can advance our understanding of soil development while providing useful soil information for land managers.

Primary Goals and Objectives: Our goals are to determine the influence of precipitation and volcanic ash on the morphology, mineralogy, and composition of soils across a climatic gradient of western Haleakalā. This will enable us to model the relationships between precipitation, temperature, weathering stage, mineralogy, and elemental loss of these volcanic soils (Chadwick et al., 2003; Chorover et al., 2004).

DREXEL UNIVERSITY

Award: ATMOS 41 all-in-one weather stations, Infrared radiometers, ZL6 data loggers and ZENTRA Cloud

COMBATTING URBAN HEAT STRESS WITH SMALL-FOOTPRINT GREEN STORMWATER INFRASTRUCTURE IN PHILADELPHIA’S MOST HEAT-VULNERABLE NEIGHBORHOODS

In Philadelphia and other urban areas, the urban heat island (UHI) effect exacerbates the risks associated with extreme heat due to heat-absorbing surfaces and limited vegetation. This impact is not equally distributed over the urban landscape but concentrates in areas with heightened levels of heat absorbing materials and reduced tree cover. Surface temperature maps identify some neighborhoods as hotter on average than other areas, sometimes differing by as much as 8 °F. These warmest neighborhoods are disproportionately inhabited by people of color and people experiencing poverty.

Philadelphia’s climate is expected to warm steadily over the coming century, with four to ten times as many 95+ °F days expected per year by 2100. This increase in extreme heat events is projected to result in six times as many heat related deaths.

One resource used to combat the urban heat island effect is green infrastructure. Philadelphia hosts a long-term green infrastructure plan that utilizes decentralized environmental assets that mimic the ecology of the pre-development landscape with the goal of reducing pollution from urban stormwater. Restoring the natural ecological processes of the land cover includes reduction of the impervious surfaces that also retain heat and reintroducing vegetated space, further reducing temperatures through evaporative cooling.

Philadelphia’s green infrastructure plan, called Green City, Clean Waters, is housed within the Water Department and serves primarily to reduce combined sewer overflows. This tight focus on a single goal underutilizes the green infrastructure network, neglecting to consider impacts on urban heat. The co-benefits of using green infrastructure designed primarily for stormwater pollution reduction to mitigate the urban heat island effect are not well understood. By sensing temperature differences in and around a green infrastructure site, this study seeks to better quantify the impact of small footprint green infrastructure designed to reduce stormwater pollution on urban surface and air temperatures.

UC DAVIS

IRRIGATION MANAGEMENT OF DIFFERENT ALMOND VARIETIES WITHIN THE SAME ORCHARD DURING IN-SEASON AND POST-HARVEST PERIODS

Almond production in California has unique water issues, including the need for post-harvest irrigation and the presence of alternating rows of different varieties within the same orchard to establish effective pollination. Many almond orchards are arranged in rows that alternate between a high-yielding variety (e.g., Nonpareil) and one or two pollinator varieties (e.g., Butte, Aldrich).

Traditionally, farmers have set up their irrigation systems to irrigate the entire orchard the same and cannot independently irrigate the different almond varieties. Instead irrigation decisions are based on the highest-yielding variety (usually Nonpareil). Since each almond tree variety experiences critical growth stages (e.g., hull-split, harvest, bud differentiation) at different times, they may also have different water needs at one time and may benefit from independent irrigation management. This project is investigating how to independently irrigate different varieties without interfering with their shifted growth stages and harvest activities.

Goal: Evaluate almond orchard growth, yield, nut quality, and water productivity response to independent regulated deficit irrigation management by variety during in-season and off-season. Soil water monitoring using TEROS 12 and TEROS 21 sensors will provide feedback on adequacy of the irrigation. In situ water retention curves will be produced using volumetric water content and soil water potential to understand the soil water retention characteristics in each treatment.

UNIVERSITY OF MANITOBA

WATER MANAGEMENT OF CANOLA AND SOYBEANS UNDER TILE DRAINAGE IN THE CANADIAN PRAIRIES

An efficient water management system for increased crop production without compromising environmental sustainability is necessary to address global food shortage, water scarcity, salinization, and increasing climate extremes. Southern Manitoba is a major crop production area, blessed with fertile soils and a flat topography. However, major problems limiting maximum production in the region are waterlogging caused by snowmelt infiltration and uneven rainfall patterns.

Proper water table management (WTM) offers the dual function of irrigation and/or drainage. However, like most natural systems involving complex and interrelated processes, water management has necessitated the use of agricultural systems models. The objectives of this proposal are (i) to assess different water table management techniques using subirrigation and tile drainage on canola and soybean yield (ii) to calibrate and validate the HYDRUS (2/3D) model using the measured soil water content within the root zone, spatially and temporally.

Field plots with three replicated treatments (controlled drainage (CD), Free drainage (FD) and No Drainage (ND)) already installed in a strip-plot design in southern Manitoba will be used over three growing seasons (2019-2021). Each treatment is replicated three times giving a total of 18 plots for the two crops in rotation. Canola and soybean yield will be measured and compared across harvested rows in each treatment. Phosphates and nitrates quantities will be measured in soil and drainage water. Water table depths will be measured using observation wells installed with level loggers (owned).

Goal: Look at water table management techniques for increased crop production of canola and soybeans in the Canadian Prairies. Products awarded include the TEROS 10, ZL6 and TEROS borehole installation tool (rental).

UNIVERSITY OF WISCONSIN

IMPROVING IRRIGATION PLANNING AND EARLY PREDICTION FOR AGRICULTURAL DROUGHT IN WISCONSIN

The risks of climate extremes such as heat waves and droughts are increasing and have threatened the north Central America agricultural system in form of increased drought duration, intensity and reduced crop yield. Current drought forecasts cover large regions and are not specific to individual farms. Drought predictive capabilities are in need of significant improvement. Here, we propose to improve forecasting of how crops stress changes over time during different stages of growth through advanced mapping of evapotranspiration (ET) with new NASA spaceborne sensors. This goal will be accomplished by high-resolution (30 m) mapping of surface temperature and water loss by crops in central sands Wisconsin with the recently launched NASA ECOsystem Spaceborne Thermal Radiometer Experiment (ECOSTRESS) mission and the polar-orbiting NASA Soil Moisture Active Passive (SMAP) and ESA Sentinel microwave satellite.

From these two products, we will develop, calibrate and evaluate a new ET product against field measurements of ET from a network of crop eddy covariance flux towers and soil moisture sensors. These towers are currently operating in irrigated farm operated by Heartland Farms (where potatoes, corn and soybean crops are rotated) and pine plantation in Tri-county School Forest of WI. New field-scale weekly ET maps will indicate when plants are under stress and farmers can take actions and use limited water resources efficiently to maintain productivity

Goal: Use ground-based measurements to validate modeled evapotranspiration (ET) from NASA’s ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) while looking at the crop water use of potatoes, corn, and soybeans. Products awarded include the TEROS 12, ZL6 and ATMOS 41.

UNIVERSITY OF IDAHO

 DEVELOPMENT OF A WEATHER-BASED DISEASE WARNING SYSTEM FOR IDAHO VINEYARD

Producers need real-time detection of crop damaging events in order to better optimize onfarm resource management. A study is proposed to develop a site specific decision support tool for on-farm management of crop damaging weather events. Weather stations will be distributed across two fields of varying landscapes in an Idaho vineyard to identify environmental factors associated with downy mildew (Plasmopara viticola) disease. Vineyard canopies will be surveyed to detect the plant physiological response to water and disease induced stress. Maps of the spectral reflectance of vineyard canopies will be compared to distributed weather data. The ability of machine learning algorithms to advance disease prediction will be assessed.

Goal: Collect environmental data to develop predictive models and detect early onset of downy mildew in vineyards for disease and risk management. Products awarded include the PHYTOS 31, ATMOS 41, TEROS 21 and TEROS 12.

UNIVERSITY OF IDAHO

SPATIO-TEMPORAL VARIABILITY IN DRAINAGE AND NUTRIENT FLUX AT WATER RECLAMATION FORESTS

Land application of reclaimed water on established forests is a cost-effective and environmentally friendly disposal alternative, particularly in Idaho, where tree growth is limited by soil water and nutrient availability. However, elevated risk of nutrient saturation and leaching has been attributed to increased constituent loading from prolonged application of reclaimed water (Barton et al., 2005; Hook and Kardos, 1978). The saturation point is indicative of lifespan of reclaimed water land-application forest sites.

There are scores of permitted reclaimed water reuse facilities in Idaho. These facilities include management units having received reclaimed water for various time periods up to 50 years. These variable periods of operation offer an opportunity to compare spatio-temporal variability in drainage and nutrient fluxes which would ultimately help determine their longevity. For the proposed research, METER G3s will be utilized to measure variation in nutrient drainage within a suite of other measurements.

Goal: Study the effect of reclaimed water land application on established forests and their efficacy as “sinks” for prolonged disposal of recycled water. Products awarded include the drain gauge G3 lysimeter, G3 depth sensor and G3 auto pump.

WASHINGTON STATE UNIVERSITY

NUTRIENT LOADING TO GROUNDWATER FROM WASTEWATER EFFLUENT IRRIGATION IN A NORTHERN IDAHO LAKE

Lake water quality is continually hindered by anthropogenic sources in newly developed zones. Limiting nutrient loading to lakes can reduce eutrophication effects, hence identifying the source of nutrients is a step towards improving water quality.

This project aims to identify the main pathways water takes from sources with high concentrations of nutrients to the lake. Instrumentation from this fellowship will allow quantification of nutrient leaching through soils to groundwater to provide a loading basis and a starting point for a reactive transport model. Complementary findings will include water transport rate identification and nutrient resident times using an isotopic signature.

Goal: Examine nutrient loading of nitrogen and phosphorus into local lake systems as a result of subsurface transport (deep drainage). Products awarded include the drain gauge G3 lysimeter, CTD+DG depth, EC and temp sensor for the G3, ATMOS 41, ZL6 and ZENTRA Cloud.

YALE UNIVERSITY

SPATIAL AND TEMPORAL DYNAMICS OF HYPOXIC FLOODS AND FISH KILLS IN A TROPICAL RIVER

Hypoxia in rivers is uncommon due to the high rates of reaeration in flowing waters, and when it does occur, it is typically associated with high anthropogenic nutrient loading. Hypoxic floods can be catastrophic for river biota, often leading to widespread fish kills or other alterations in fish community composition and behavior.

I have been documenting frequent hypoxic floods (13 in 3 years) and fish kills (5 in 9 years) in the Mara River, East Africa, and my research has shown they are caused by the flushing of hippopotamus pools. There are over 4000 hippopotami in the Kenyan portion of the Mara River bringing in over 3500 kg of organic carbon into the aquatic ecosystem each day. I have shown that hippo pools within the 3 tributaries of the Mara become anoxic under low discharge, and increases in discharge flush out the hippo pools and carry a hypoxic pulse of water through the river downstream. However, the spatial and temporal dynamics of these hypoxic floods remain unknown.

My research aims to understand the drivers of variability in these hypoxic floods and how these hypoxic floods are propagated downstream. This understanding will be critical to predicting how the frequency and intensity of these events will be influenced by climate and land use change. Differences in the degree of hypoxia across different flood events are likely driven by differences in the time since hippo pools in a given area have been flushed out and the size of the rainfall event driving the flood. Because rainfall in the Mara region is highly localized within and among catchments, and the biogeochemistry that causes hypoxia can vary among pools and tributaries, understanding these dynamics requires fine scale spatial and temporal data on precipitation patterns across the catchment. To document the origin of hypoxic floods, we need to understand drivers of their variability and how they propagate through the river network. I will document hippo pool biogeochemistry and the discharge and dissolved oxygen (DO) response of the tributaries and main stem of the Mara River in response to the rainfall intensity and frequency from each sub-catchment of the Mara.

I will install a METER ATMOS 41 weather station in each of the three sub-catchments of the Mara River to monitor rainfall intensity, frequency and duration. I will continue to document the occurrence of hypoxic flood events in the Mara River with a water quality sonde installed downstream of all the hippo pools. I will also continue to map and survey the biogeochemistry of all hippo pools (~ 20-30) within the 3 sub-catchments of the Mara. I will model the degree of hypoxia in each flood event as a function of hippo pool biogeochemistry, time since last flushing and the timing and quantity of rainfall within each sub-catchment.

DREXEL UNIVERSITY

EFFECT OF PLANT ROOT CONFIGURATION ON THE PERFORMANCE OF URBAN DECENTRALIZED GREEN STORMWATER MANAGEMENT FACILITIES DUE TO SPATIOTEMPORAL VARIATION OF FIELD MEASUREMENTS OF EFFECTIVE SATURATED HYDRAULIC CONDUCTIVITY

Often a constant infiltration rate is assumed when designing green infrastructure (GI) sites. However, various studies suggest that the infiltration rate is dynamic and varies spatially and temporally during wet weather events. This research study will assess the effect of root zone configuration (both type and density) on the spatial variability of field saturated hydraulic conductivity values (K_fsat) using METER’s SATURO infiltrometer within the site. The study will also compare K_fsat and the unsaturated hydraulic conductivity (K_fs) measured with METER’s MiniDisk Infiltrometer values under different hydrologic conditions, and over three growing seasons.

The research will be performed on four, fully monitored urban GI sites with established vegetation. The results will be statically analyzed to derive generalizable rules reducing in-situ GI monitoring needs, and to calibrate 2D/3D models.

The proposed research aims to assess the effect of root zone configuration (both type and density), and the effect of ponding and inflow depths on the infiltration performance of urban GI.

UNIVERSITY OF TENNESSEE – KNOXVILLE

 INFLUENCE OF PLANT ROOTS AND MYCORRHIZAL HYPHAE ON SOIL HYDRAULIC PARAMETERS

The proposed research will focus on how plant roots and mycorrhizal hyphae impact soil hydraulic properties. Laboratory experiments will be performed to measure saturated hydraulic conductivity (KSAT) and soil water retention (HYPROP), in the presence and absence of roots, with and without mycorrhizae. Neutron imaging will be used to visualize and quantify root and mycorrhizal length density and morphology. The resulting data sets will be parameterized for inclusion in models used to predict flow and transport within the vadose zone. This work will address a key research uncertainty in our ability to adequately model plant-soil hydraulic relationships.

The goal of this research is to assess the impact of plant roots and mycorrhizal hyphae on soil hydraulic properties. The objectives are to measure the soil water retention curve, ?(?), and saturated hydraulic conductivity, ?_sat in soil containing roots (with and without mycorrhizae) vs. no roots, and to visualize and quantify the spatial distributions of roots and hyphae. Based on a review of the literature, I hypothesize that roots and hyphae will change ?(?) by increasing the amount of water that is held at a given matric potential, particularly close to saturation. I also hypothesize that roots and hyphae will increase ?_sat relative to soil in which they are absent.

UNIVERSITY OF WISCONSIN

QUANTIFYING THE EFFECTIVENESS OF IRRIGATION SCHEDULING TO INCREASE WATER USE EFFICIENCY IN THE WI CENTRAL SANDS

Groundwater from a shallow, unconfined aquifer in the Wisconsin Central Sands (WCS) replenishes prized aquatic ecosystems and simultaneously supplies irrigation water to support a $450 million agricultural industry. To successfully balance these valuable ecosystem services, it is imperative we quantify the effectiveness of irrigation management strategies for reducing consumptive groundwater use while maintaining acceptable yields.

My proposed research will formally test the ability of the Wisconsin Irrigation Scheduling Program (WISP) – a tool available to farmers but severely underutilized – to increase crop water-use efficiency (WUE) and decrease consumptive groundwater use on-farm.

Potato and sweet corn crops will be examined across four fields during the 2018 and 2019 growing seasons. In a paired field experiment, half of the fields will be irrigated using the freely available WISP (https://wisp.cals.wisc.edu/), and Isherwood Farms will irrigate the remaining fields according to intuition and experience.

User inputs will be measured as follows: percent canopy cover with the Canopeo phone application, soil moisture with METER 5TM sensors/ProCheck, and irrigation/precipitation with METER ECRN-100. Previously installed METER G3 drain gauges (3-5 per field) and daily ET measurements (ET = rainfall + precipitation – Δ soil storage – drainage) will validate WISP deep drainage and ET calculations. One METER EM60G per field will log irrigation/precipitation (ECRN-100), soil moisture (10, 20, 40, 80 cm with 5TM; owned), and deep drainage (G3 drain gauge; owned) data. The EM60G’s automated data collection is vital for consistently tracking daily precipitation/irrigation inputs and accurately operating WISP. EM50s will collect data from additional lysimeters and soil moisture sensor sets (2-3 depending on the field) in order to capture a full range of variability. Yield will be determined by harvesting 6 meters of row from 15 field locations at the end of a crop growth cycle. Differences in deep drainage, yield, ET, and soil moisture will be compared between WISP-intuition irrigation regimes and WISP-Agro-IBIS models to evaluate potential water savings and opportunities for WISP improvement.

UNIVERSITY OF WYOMING

THE EFFECTS OF ENVIRONMENTAL CHANGE ON CARBON CYCLING ACROSS THE SEMI-ARID WEST

Increased availability of nitrogen (N) has the potential to alter many ecosystem functions—and is doing so already. This is largely due to the widespread response of net primary productivity (NPP) and soil respiration to N. Anthropogenic fixation of N has increased inputs into the biosphere from 0.5 kg N ha^-1 yr^-1 to upwards of 10 kg N ha^-1 yr^-1. Within semi-arid environments, the relationships between available N and ecosystem processes are especially complex due to strong limitation by low—and highly variable—precipitation. This causes temporally complex co-limitation by water and N. In addition, temperature is known to have significant effects on soil respiration. Given the IPCC projections, in which both N and precipitation are altered, the current development of energy resources in the western US provides an opportunity to ask basic and applied research questions related to the effects of increased nitrogen and water availability on carbon cycling. To better understand these effects, I will examine the interactive effects of nitrogen and water application on the carbon cycle and assess the relative effects of plant and microbial communities on carbon cycling and the carbon budget. METER weather station implementation will allow me to monitor site conditions (i.e., precipitation, air temperature, soil moisture, and soil temperature) with high temporal resolution, increasing the realm of inference of this study.

UNIVERSITY OF WYOMING

DEGRADATION OF SOIL-APPLIED HERBICIDES UNDER LIMITED IRRIGATION

Soil-applied herbicides are important for controlling weeds in many crops, as they offer a broadened control spectrum and chemical diversity, especially when fewer POST-applied herbicides are available. However, if soil-applied herbicides persist in the soil too long, there is risk for damage to susceptible rotational crops in succeeding years. As herbicide degradation in the soil is highly dependent on water, imminent needs to reduce agricultural water use in the future could lead to limited herbicide degradation and a greater risk for carryover. This project seeks to understand how limited irrigation affects the efficacy and carryover of soil-applied herbicides in Wyoming’s irrigated crop rotations. A two-part field study is currently being undertaken by applying four soil-applied herbicides to dry beans and four soil-applied herbicides to corn. In 2015, three irrigation treatments (100%, 80%, 69% of crop evapotranspiration) were applied to both crops, and soil moisture was monitored using ten METER Em50 data loggers each with four GS-1 soil moisture sensors. Volumetric soil water content of the three irrigation treatments averaged 22%, 18%, and 17% throughout the growing season. Crop yield decreased as irrigation was reduced. Soil samples collected at regular intervals following herbicide application will be analyzed in 2016 for herbicide level and used to perform a greenhouse bioassay to determine crop response to residual herbicide. Crop response will also be evaluated in the field during the second year when sugar beet, sunflower, and dry bean or corn will be planted over the original plots and assessed for herbicide damage.

WASHINGTON STATE UNIVERSITY

STRIP TILLAGE AND COVER CROPPING FOR ENHANCED WATER USE EFFICIENCY IN WESTERN WASHINGTON ORGANIC VEGETABLE FARMS

Growing soil health and water use concerns in conventional tillage systems have led to increased interest in reduced tillage practices due to enhanced soil quality, moisture retention, and decreased erosion. A balanced approach utilizing strip tillage and high-residue cover crops has the potential to reduce these negative effects while protecting soil health and conserving water. High residue vegetative mulches created by spring-terminated cover crops have been shown to suppress weeds in organic systems as well as increase soil moisture when compared to conventional tillage systems. This project will investigate how these high-residue cover crop based strip till systems can improve water use efficiency by investigating water dynamics of the flailed mulch layer in comparison to bare ground systems.

A fall-planted cereal rye cover crop terminated during mid-anthesis via flail mowing will be subjected to strip tillage or full tillage prior to transplanting squash. Separate drip irrigation application schedules will be maintained per treatment utilizing the WSU AgWeathernet irrigation scheduler platform, paired with METER 5TM volumetric moisture sensors and monitored in real time with Em50G wireless loggers. Temperature and moisture data will be taken at two soil depths and two locations across the bed. Upon completion, this project will help address the nexus of food, energy, and water with the potential to increase farming system resiliency to climate change by conserving water resources in Washington state.

UNIVERSITY OF TEXAS AT AUSTIN

RETHINKING MEASUREMENTS OF PLANT WATER STATUS IN RESPONSE TO DROUGHT

Drought is a primary factor limiting plant productivity, adversely affecting plants from the molecular to the physiological level. Many studies have examined the effects of drought, but few include the effects of fungal symbionts. Yet endophytic fungi that colonize leaves can improve plant drought tolerance by an order of magnitude or more. For instance, fungal endophytes can reduce plant water loss by closing plant stomates and prevent cellular desiccation by accumulating solutes in plant cells. In some cases, the presence of a fungal endophyte completely negates the effects of drought on plant growth and transpiration efficiency. As such, fungal symbionts may lead researchers to incorrectly identify mechanisms of drought tolerance within plants. Furthermore, fungal effects may explain why current conductance models have been unable to predict observed stomatal responses to water stress. Therefore, to better understand plant drought dynamics, I propose to use METER’s SC-1 Leaf Porometer to partition the effects of soil moisture and endophytes on plant stomatal conductance.

MICHIGAN TECHNOLOGICAL UNIVERSITY

UNDERSTANDING SOIL CONDITIONS IN BOREAL-TAIGA ECOSYSTEMS AND HOW THEY INFLUENCE WILDFIRE EXTENT, SEVERITY, AND DISTRIBUTION

The Arctic-boreal region is experiencing a significant change in climate, trending toward warmer, longer summers. These increased temperatures are expected to dry fuels, causing them to become more susceptible to ignite and burn during extended wildfire seasons. Wildland fires are the number one disturbance in Canada’s Northwest Territories (NWT), and permafrost thaw is the second largest disturbance factor. It is important to understand the relationship between these two disturbances, as they drive and influence each other in a positive feedback loop. These processes are driven by several factors, including weather and climate, topography, and soil composition. In order to understand how the effects of wildfires vary across different ecological zones and permafrost conditions, preseason soil and fuel moisture patterns are being studied both on the ground and with remote sensing technology. Long-term trends in soil moisture patterns leading up to the 2014 fire season near Yellowknife, NWT, will be compared to field measurements taken during summer 2016. METER’s 5TM sensors and Procheck hand-held devices will be used to measure soil conditions, including moisture and organic matter; the SATURO will test the field-saturated hydraulic conductivity to estimate how much water is available for runoff and the regeneration of vegetation. Measurements will be taken at a variety of post-fire conditions (unburned to high burn severity) and permafrost interactions (continuous, discontinuous, and sporadic). These results will contribute to an ongoing effort of understanding the vulnerability of Boreal-Taiga ecosystems to increasing wildfire activity in a changing climate.

UNIVERSITY OF WASHINGTON

THE SEARCH FOR CO₂ FERTILIZATION

Trees are merchants; they sell water to the atmosphere in exchange for the CO₂ they need to photosynthesize sugars. The exchange rate, or ‘water-use efficiency’ that drives the plant carbon-water marketplace is a function of atmospheric CO₂ concentrations. Thus, theoretically human carbon emissions, which have increased atmospheric CO₂ by 40% since 1850, should increase plant water use efficiency, resulting in “CO₂ fertilization” of our forests and crops. However, evidence for CO₂ fertilization is extremely mixed. I seek to understand when, where, and why trees experience CO₂ fertilization by using METER equipment to quantify the environmental constraints (e.g., the availability of water, light, temperature, relative humidity) experienced by two tree species, Abies lasiocarpa and Populus tremuloides, across their elevation ranges in southwest Colorado. By combining these environmental data with existing tree growth and water-use efficiency records from tree cores, I will use a parameterized forest growth model (3-PG) to determine how environmental constraints determine whether and how much trees benefit from increasing carbon dioxide concentrations.

UNIVERSITY OF TENNESSEE KNOXVILLE

CORPSE DECOMPOSITION HOT SPOTS: MONITORING CHANGES IN GRAVE SOILS

Corpse or carcass decomposition has garnered interest from both forensic and ecological perspectives. Our research focuses on the microbial ecology of terrestrial vertebrate mortality decomposition events, with an emphasis on changes in soil biology and chemistry. We plan to use METER soil moisture sensors to predict both soil moisture and fat/lipid content in these decomposition soils in lab and field experiments. This will provide new knowledge about these sensors and their potential applications in forensic science.

UNIVERSITY OF IDAHO

HYDRAULIC PHYSIOLOGY OF PLANTED DOUGLAS-FIR SEEDLINGS IN RESPONSE TO WATER-LIMITING CONDITIONS

This project will measure the hydraulic conductivity of Douglas-fir seedlings, and determine how seedling hydraulic conductivity changes in limiting soil water conditions. Hundreds of thousands of Douglas-fir seedlings are planted each year in the state of Idaho, and are subjected to a wide variety of environmental conditions. Field observations show that planted Douglas-fir seedlings are not surviving; limited soil moisture at the planting sites is one suspected cause of seedling death. The project will address a forestry problem, the failure of planted seedlings to survive, with the tools and mechanisms from the discipline of plant hydraulic physiology, including a high-pressure flow meter, a Sperry apparatus, and METER instruments. We will measure morphological and physiological characteristics of the seedlings before and after planting. Control seedlings will be well-watered throughout the experiment, and treatment seedlings will experience moderate or extreme drought conditions. The results will be analyzed using analysis of variance. The results will elucidate how the hydraulic physiology of the seedlings responds planting, which will help improve survival of seedlings and ensure reforestation and restoration goals are met.

MICHIGAN STATE UNIVERSITY

EFFECTS OF GRAVEL LAYER PARTICLE SIZE AND SUB-GRADE SLOPE ON THE MAGNITUDE OF SPATIAL PATTERN OF SOIL WATER IN A VARIABLE-DEPTH USGA-SPECIFICATION PUTTING GREEN

Uniform distribution of soil water in high-sand content putting greens is a major concern for golf course superintendents. Although gravel is commonly used as a component of a sand-based root zone in order to increase moisture retention, the contour and slope in putting greens significantly affect moisture retention due to gravity. As a result, coarse-textured soils become prematurely dry in higher elevations, and excessively wet in lower elevations. This non-uniform wetting of soil not only could hamper putting green performance, but also, could increase water and labor inputs. The objective of this study is to assess the impact of gravel layer particle size and slope on soil water content in a variable-depth (shallower at the slope apex, yet deeper at the slope base) high-sand content root zone. Due to lack of published research and the United States Golf Association’s (USGA) wide-ranged specification for selection of a gravel based on the root zone material, determining the optimal bridging, filtering, permeability, and uniformity factors capable of increasing root zone soil moisture uniformity across the undulations of a variable-depth, high-sand content putting green is critical. Our objective is to evaluate the effects of gravel layer particle size and sub-grade slope on the magnitude and spatial pattern of soil water in a variable-depth, USGA-specification putting green. Our hypothesis is the following: increasing the particle size difference between the gravel and root zone layers, in combination with a variable-depth root zone, will improve soil moisture uniformity in an undulating putting green.

 KANSAS STATE UNIVERSITY

A REPEATABLE SCREENING OF WHEAT AND ITS WILD RELATIVES FOR MOISTURE STRESS TOLERANCE

Previous studies have identified “drought tolerant” accessions of the wild wheat species Aegilops geniculata Roth and common wheat (Triticum aestivum, L.) in controlled environments. Controlled environment screening is necessary to grow unadapted germplasm and to isolate moisture stress from additional stresses in the field. Many greenhouse drought screenings suffer from confounding issues such as soil type and the resulting soil moisture content, bulk density, and genetic differences for traits like root mass, rooting depth, and plant size. Monitoring water potential in the soil and the plant is the only quantifiable way to impose a consistent and repeatable treatment. With the development of a soil-moisture retention curve for a homogenous growth media, the moisture treatment could be maintained at a biologically relevant matric potential, and corresponding plant water potentials could be recorded. METER EC-5 volumetric water content sensors, METER MPS-6 matric potential sensors, as well as column tensiometers are being used to monitor soil moisture conditions in a greenhouse experiment using 182 cm tall polyvinyl chloride (PVC) growth tubes using the homogenous growth media, Profile Greens Grade. Previously characterized wheat varieties are being grown in a pilot study, and an advanced collection of Aegilops geniculata will be screened in the larger system. Measurements will be taken for days to senescence, biomass, shoot:root ratio, rooting traits, yield components, leaf water potential, leaf relative water content, and other physiological observations between moisture limited and control treatments. This data could be a quantifiable way to classify genotypes for response to moisture stress.

Awarded 13 MPS-6 water potential & temperature sensors and 26 EC-5 soil moisture sensors

 IOWA STATE UNIVERSITY

SOIL THERMAL AND HYDRAULIC PROPERTIES FOR DYNAMIC BULK DENSITY DURING WETTING AND DRYING CYCLES AFTER TILLAGE

Surface soil is a complex, dynamic interface which dictates mass and energy transfer between land and atmosphere and determines water flow and partitioning in the hydrological cycle. Its properties are considered dynamic because they are controlled in part by soil water content, which can change quickly with wetting events or slowly over sustained periods of drainage, plant uptake, and evaporative drying. A common assumption in hydrologic studies considering dynamic soil surface properties is that soil bulk density is static. Natural processes (e.g., freeze- thaw) and anthropogenic modifications (e.g., tillage) impact soil bulk density. Therefore, if transient bulk density can be quantified, the impact on soil thermal and hydraulic properties can be measured. In order to continually monitor the changes in soil thermal and hydraulic properties in a tilled field, I propose using thermo-TDR sensors to determine in situ soil water content and thermal properties, latent and sensible heat fluxes, in addition to assessing the state of soil bulk density and porosity. I request water potential and water content sensors to enable the determination of field water retention characteristics and hydraulic conductivities.

Awarded 18 MPS-6 water potential & temperature sensors, nine EC-5 soil moisture sensors

NORTHERN ARIZONA UNIVERSITY

DO SOIL MICROBES INFLUENCE PLANT RESPONSE TO HEAT WAVES?

Heat waves and drought disrupt ecosystems and are increasing in frequency and intensity, yet they receive much less research attention than long-term, gradual warming. The acute effects of these events are profound, reducing aboveground productivity by 30% across the European continent in 2003. Although understudied, heat waves and drought likely produce legacy effects mediated by the soil microbial community. I will manipulate rhizosphere communities in vivo and evaluate the performance of native grasses transplanted under a field-applied heat wave, an increasing scenario in the southwest and a growing challenge within ecological restoration. I expect that heat waves will alter soil microbial community structure, reducing bacterial abundance but preserving fungal abundance. Second, I expect that growing grasses with heat-waved inoculum will “prime” plants for heat tolerance, due to acclimation of rhizosphere microbes. METER instrumentation will shed new insight onto the abiotic factors associated with heat waves, including associated impacts to microbial-available and plant-available water.

Awarded eight MPS-6 water potential & temperature sensors, eight GS1 soil moisture sensors, four Em50 data loggers

UNIVERSITY OF GEORGIA

CONTINUOUS MONITORING TO DETERMINE HOW ENGINEERING HYDRAULIC FLOWPATHS MAINTAIN WATER QUALITY AND QUANTITY DURING SURFACE COAL MINING AND VALLEY FILL OPERATIONS

Researchers have found that salinity levels—as measured by conductivity, a proxy for total dissolved solids (TDS) loadings—are the strongest indicator of stream degradation below surface coal mining and valley fill (SCM/VF) operations throughout central Appalachia. We are currently investigating the effectiveness of an experimental “hydrologic isolation” mine reclamation method designed to maintain water quality and quantity downstream from SCM/VF operations by minimizing groundwater contact with high salt-producing overburden. The identification and characterization of source water contributions to streamflow using conductivity will help us determine how the hydrologic isolation method affects the nature and duration of surface water-groundwater interactions and increase our understanding of the dominant hydrologic flowpaths contributing to streamflow in mined watersheds. Continuous monitoring data provides much greater temporal resolution than quarterly or monthly monitoring data and is critical to understanding how conductivity varies seasonally and with varying antecedent rainfall conditions. The goal of our study is to evaluate how hydrologic engineering practices that control the movement of groundwater flow through SCM/VF mine sites can impact streamflow generation mechanisms and water chemistry. Our research objectives include evaluating the effect of hydrologic engineering on reducing solute loadings to and conductivity levels in receiving streams and the mechanisms controlling streamflow generation processes and water chemistry below SCM/VF.

The collection of continuous hydrologic and water chemistry data using METER’s Em50R remote data logging system coupled with CTD-10 sensors will help us understand the hydrologic dynamics at a remote SCM/VF site located in Magoffin County in the eastern coal fields of Kentucky.

Awarded four CTD-10 sensors, three Em50 data loggers, one data station

COLORADO SCHOOL OF MINES

EXPERIMENTAL AND MODELING INVESTIGATION OF SHALLOW SUBSURFACE PROCESSES INFLUENCED BY LAND-ATMOSPHERE INTERACTIONS/APPLICATIONS TO LANDMINE DETECTION

One of the most prolific, worldwide environmental hazards are antipersonnel landmines. The success of technologies to detect landmines is dependent on many factors to include the landmine’s physical composition and the length of time in the ground from emplacement. However, one commonly overlooked area is the environmental conditions in which the landmine is placed. By gaining a greater understanding of the environmental conditions in the vicinity of a landmine, we can better calibrate numerical models used to develop algorithms that interface with different detection technologies. Characterizing the environmental conditions in the vicinity of a landmine emplacement location is the focus of this research. Numerous numerical and analytical models to predict the physical properties of the shallow subsurface have been developed. The fundamental knowledge of the character of the terrain and the dynamic processes that alter the properties of the terrain are key to these models. The goal of this research is to improve our understanding of the non-isothermal, multi-phase flow processes of water, water vapor, and air in the shallow subsurface in order to better predict the spatial and temporal distribution of soil moisture.  This will ultimately provide more spatially refined soil moisture and temperature distribution predictions, enabling better understanding to model, simulate, and predict the environmental conditions that are most dynamic to mine detection performance.

Awarded five VP-3 temperature & relative humidity sensors, ten ECT air temperature sensors, ten EC-5 soil moisture sensors

WASHINGTON STATE UNIVERSITY

BIODEGRADABLE PLASTIC MULCH: DEGRADATION AND IMPACTS ON SOIL QUALITY

Application of conventional plastic mulch (CPM) in agriculture is a common practice by most specialty crop producers worldwide. It offers the benefits of increased water-use efficiency plus weed, pest, and disease control. This subsequently improves crop yield and quality. Nonetheless, producers need to retrieve and safely dispose CPM after usage, which increases the total production cost.  Substituting CPM with biodegradable plastic mulch films (BPM) will alleviate disposal needs. However, potential impact on agricultural soil ecosystems needs to be assessed before BPM adoption. The objectives of my research are to

I will assess soil quality using the USDA Soil Quality Test Kit available from Gempler. Since soil temperature and moisture content are important parameters that govern chemical reaction rates and microbial activity and are likely to vary among the different BPM treatments, they will be monitored using METER’s 5TM soil moisture and temperature sensors installed at 10 cm and 20 cm depths. I will also install METER’s G3 drain gauges at a 30 cm depth to collect leachate samples for analysis of BPM particulates. The degradation of BPM over time will be examined by assessing the material properties and also measuring the particle size and surface area via photography, digitization of the photographs, and image analysis using the Image J software.

• Evaluate leaching of BPM degradation products through soil

UNIVERSITY OF GEORGIA

USING NORMALIZED DIFFERENCE VEGETATION INDEX (NDVI) AS A PROXY FOR PLANT SIZE IN PREDICTIVE WATER USE MODELS TO FACILITATE PRECISION IRRIGATION

Precise irrigation based on plant water needs not only allows for optimal plant growth but also conserves water and alleviates environmental pollution from fertilizer and pesticide runoff. A thorough understanding of crop-specific water requirements is essential for more efficient irrigation. However, plant water use changes on a daily basis, driven by variations in environmental conditions as well as changes in plant size over time. While environmental conditions are relatively easy to measure, direct determination of plant size is often destructive and time consuming. Remote sensing of vegetation indices, such as the normalized difference vegetation index (NDVI), provides a continuous and non-destructive method to estimate canopy size for use in water use models. My current work using METER NDVI sensors will develop quantitative models that predict daily water use (DWU) of bedding plant species based on environmental factors and NDVI, a proxy for plant size. The goal is to use NDVI in place of ‘crop coefficients’ which are commonly used in agronomic applications.

Our preliminary data show that NDVI is highly correlated with plant growth, and a multiple linear regression model developed using only radiation and NDVI explained over 85% of variations in DWU. The inclusion of additional environmental variables or reference evapotranspiration can refine these models. Therefore, we will carry out one additional study for model validation purposes and scale up through collaboration with commercial growers and develop study sites in nurseries.

Awarded six SRS NDVI sensors,  two SRS PRI sensors, one ProCheck, one PAR sensor, one Pyranometer, one VP3 temperature & humidity sensor

VIRGINIA TECH

WATER CONSERVATION IN CONTAINER-SIZED PRODUCTION VIA ENGINEERING SOILLESS SUBSTRATES FOR INCREASE AVAILABLE WATER

There is a growing realization that water is a finite resource of which agriculture, including container crop production, is a leading consumer. Nearly two-thirds of all ornamental crops produced in the U.S. are grown in containers utilizing soilless culture, in which upwards of 20,000 gallons of water per acre per day can be applied to yield marketable crops. Soilless substrates have been developed to provide ample air-filled porosity, ensuring sufficient drainage, thus allowing growers to water in excess to avoid risks associated with water stress. However, with a looming water crisis more water-sustainable production practices are needed.

My research involves manipulating soilless substrate hydrophysical properties in an effort to better understand how water moves through and interacts with substrate pores and particles. Furthermore, this research will determine how variations in hydrophysical properties of soilless substrates affect the growth and development of containerized crops. Altering conventionally used soilless substrates to have optimized hydraulic properties will allow for increased water distribution and subsequent availability in containerized substrates.  Enabling water to mobilize more readily within a container will provide roots access to higher percentages of water held within the substrate and thus increase available water. With higher percentages of water being available, growers can yield more biomass while applying less water, thus using water more efficiently during production.

The overarching goal of my research is to reduce water consumption in container production by engineering soilless substrates utilizing traditional components (e.g., Sphagnum peat and bark) without altering other production practices or investing in new technologies.

Awarded 1 WP4C dew point water potential meter

PENN STATE UNIVERSITY

CANOPY SENSING OF DROUGHT STRESS IN PURSUIT OF ECOLOGICAL CLIMATE ADAPTION

I will deploy METER Spectral Reflectance Sensors (SRS) and Infrared Radiometers (IR) to characterize the impacts of cover cropping on maize drought stress responses.  The instruments will enable measurement of maize canopy development, light use efficiency, and canopy temperature.  I will use rain exclusion shelters to impose drought stress on maize following five cover crop treatments.  The METER instruments will be installed on two mobile observatory units.  Each unit will include SRS sensors calibrated to read the normalized differential vegetation index (NDVI) and the photochemical reflectance index (PRI), with reference sensors pointed at the sky, as well as one IR.

This mobile system will build on the current set of repeated ecophysiological methods used in this study.  These include: maize height, leaf area index (LAI; METER AccuPAR LP-80), stomatal conductance (METER SC-1), pre-dawn leaf water potential (PMS Instruments Pressure Chamber), and leaf greenness (Konica Minolta SPAD).

NDVI readings will provide an earlier, more accurate, and more repeatable indicator of canopy development than LAI.  Following canopy closure, paired PRI-NDVI readings will provide insight into light use efficiency; IR readings of canopy temperature will provide an indicator of moisture stress.  Together, they will enable season-long measurement of maize stress.

These instruments will improve the temporal resolution and mechanistic specificity of my field study, enable methods development, and help validate a crop model.  More broadly, this will enhance understanding of how ecological management practices (cover crops) can aid adaptation to projected future conditions under climate change (drought).

Awarded two Em50 data loggers, two SRS NDVI sensors, two SRS PRI sensors, two Apogee Infrared Radiometers

UTAH STATE UNIVERSITY

TECHNIQUES FOR ACHIEVING PRECISION WATER STRESS IN ORCHARDS

High value tree fruit crops require careful irrigation management to conserve water resources.  Moderate water stress of these crops results in higher fruit sugar content, but a reliable indicator of tree water status is required before precision water stress can be used.  Measurements of soil moisture are unreliable because of the deep and extensive root systems of trees.  Pressure bomb measurements of stem water potential are reliable, but are labor intensive and cannot be automated.  Infrared measurements of leaf-air temperature differences are only partly effective.  Using frequency domain reflectometry soil moisture sensors inserted into the trunks of fruit trees promises to be an effective method of continuously monitoring tree water status.  Successfully relating trunk water content measurements with pressure bomb measurements and leaf to air temperature differences could provide a reliable indicator of tree water status.  This method could then be used to precisely time irrigation and/or automate precision irrigation systems in orchards throughout the world, resulting in potential water use savings, improved crop quality and less nutrient leaching and runoff.

Awarded 13 MPS-6 water potential & temperature sensors and 26 EC-5 soil moisture sensors

UNIVERSITY OF GEORGIA

IMPROVING DROUGHT TOLERANCE IN SOYBEAN WITH THE USE OF MICROCLIMATE STATIONS TO MONITOR ENVIRONMENT CONDITIONS AND PREDICT WATER STRESS FOR ACCURATE PHENOTYPING

With climate change, it is expected that events such as drought will be more frequent and extreme in the future. Drought stress is a significant issue threatening the agricultural productivity of soybean (Glycine max L. Merrill) and can reduce yields by as much as 40 percent. Varieties with improved tolerance are needed to sustain and increase soybean production to feed a continuously growing world human population.

Drought tolerance research progress in soybean has been limited to date, mainly because drought conditions are unpredictable both spatially and temporally. To make selection of drought tolerant lines easier and more predictable, knowledge of field environmental conditions is critical. Given this information, improved drought tolerance screening techniques can be used to collect accurate phenotypic data and identify drought tolerant genotypes. Molecular markers and other genomic tools developed with this phenotypic data are most reliable if the data is collected at times when differences among soybean lines evaluated accurately reflects the true phenotype of a particular genotype.

To conduct a drought tolerance study, we selected 211 soybean lines to form the panel for a genome-wide association study to identify genomic regions responsible for drought tolerance and to develop new genomic tools by evaluating drought-related traits in the field at two locations over two years. These 211 lines come from 30 countries and were selected from known geographical areas of the world prone to drought—areas with low annual precipitation and newly developed soybean lines with enhanced drought-related traits. METER microclimate stations equipped with sensors to monitor environmental conditions at the field research sites will greatly help us predict water stress and determine ideal time periods for phenotyping these drought-related traits.

Honorable Mention: awarded two Microenvironment Monitors, two Em50G remote data loggers, two GS-1 soil moisture sensors, DataTrac 3 software

WASHINGTON STATE UNIVERSITY

DEVELOPING A LIFE-CYCLE DEGREE DAY MODEL FOR MELOIDOGYNE HALPA (NORTHERN ROOT KNOT NEMATODE) TO IMPROVE WASHINGTON WINE GRAPE MANAGEMENT STATE

Root-knot nematodes are endoparasitic organisms that infest plant roots and form galls that disrupt normal translocation of sugars and water. Declines in vigor in older vineyards and poor establishment or death of young vines in replant situations have been attributed to nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent species of root-knot nematode found in Washington wine grape vineyards. Knowing when the different life stages of M. hapla are present in the soil will allow growers to target those stages that are more susceptible to management intervention.

We know that the rate of M. hapla development and infectivity is most dependent on soil temperature and moisture. As such, we foresee the ability to develop a life-cycle model based on the temperature proxy of growing degree days. Over the next two years, I will intensively sample both soil and roots for life stages of M. hapla in two vineyards, and compare that to various environmental parameters such as air-based growing degree-days, soil temperature, and soil moisture. I plan on collecting the soil parameters using the METER 5TM soil moisture and temperature sensors and Em50 data loggers.

Honorable Mention: awarded four Em50 data loggers, 12 5TM sensors, 12 MPS-6 sensors

UNIVERSITY OF IDAHO

RESPONSE OF THE PHOTOCHEMICAL REFLECTANCE INDEX (PRI) TO ENVIRONMENTAL STRESSOR CONDITIONS FOR IMPROVED PREDICTION OF GRAIN YIELD IN WHEAT

Ground-based remote sensing techniques have recently garnered wide interest from the agricultural community as a tool to track crop performance with high temporal (daily) and spatial resolution. To cope with a projected increase in temperature and periods of drought worldwide, growers and scientists could benefit from more readily available information about daily crop performance. A better understanding of crop response to environmental stress conditions using ground-based remote sensing platforms that collect and process data in real-time could lead to a more rapid and efficient method for targeting site-specific management practices at local scales; and further, provide valuable information for scaling plant reflectance spectra from the plot to the landscape scale via airborne and satellite sensors.

One technique for gathering site-specific information on crop performance is via remotely sensed vegetation indices (VIs) such as the photochemical reflectance index (PRI). My work seeks to advance the understanding and interpretation of the PRI as a remote indicator of plant stress with specific application to improving our understanding of how different environmental stress conditions may impact grain quality and quantity.

CORNELL UNIVERSITY

MICROTENSIOMETER TO CONTINUOUSLY MONITOR WATER POTENTIAL IN PLANTS

Water potential (Ψ) is the best measure of a plant’s hydration relative to growth and product yield/quality. Unfortunately, directly measuring Ψ in plant tissue is only possible through labor-intensive, destructive methods such as the leaf pressure bomb and stem psychrometer. A common alternative is to use ‘set-and-forget’ soil tensiometers to measure soil water potential (Ψ_soil) as a proxy for plant water potential (Ψ_plant), but this method is unreliable for plants with high hydraulic resistance (e.g., vines and woody species) where often Ψ_plant << Ψ_soil.

Although very accurate and simple to use, tensiometers also have two drawbacks: they are large and bulky, and tend to cavitate in even slightly dry soils. My project involves using MEMS technology to develop a miniature tensiometer (microtensiometer) that overcomes these drawbacks and thus can be embedded in plant stems to directly measure Ψ_plant, is easily mass-manufactured, is stable for months, and communicates digitally.

Now that we have a functional prototype, I will use the AquaLab 4TE dew point water activity meter to produce solutions of specific activity to test, calibrate, and characterize the microtensiometer. My intent is to improve the design of this sensor so it can be used in the field to, for instance, continuously monitor and control Ψ_plant in vineyards, and consistently produce high-quality wine grapes with an exact flavor/aroma profile.

University of Colorado at Boulder

PHYSICAL MODELING OF THE THERMO-HYDRO-MECHANICAL RESPONSE OF SOIL-GEOSYNTHETIC INTERACTION IN THERMALLY ACTIVE REINFORCED SOIL SYSTEMS

Reinforced soil structures such as mechanically-stabilized earth (MSE) walls are a widely accepted method for grade separation in civil engineering, not only to allow more room for roads along highways but also to be more efficient in how space is used on private building sites. Traditional design of these structures calls for a select type of backfill which is free-draining to combat pore water pressures from developing in the system. These select backfills are not usually found on-site or readily available and can therefore be cost-prohibitive for some projects. Poorly-draining, marginal backfills such as silts and clays, which can be found on-site, have been used in some projects, though there are still some concerns over pore water pressure developing in the reinforced zone since the soils are not free draining.

A novel method for controlling pore water pressure is to incorporate heat exchangers to cause thermally driven water vapor flow out of the reinforced zone. While this method has been shown to increase the strength of soils, it could have a negative effect on the geosynthetics, which are typically made of polymers that are susceptible to thermal changes. The objective of this research is to quantify the effects of temperature changes on the complex interaction between unsaturated, compacted soils and geosynthetics. In particular, the thermally induced water flow away from the heat exchangers will lead to changes in soil-geosynthetic interaction. A better understanding of changes in thermal properties and how these systems function is instrumental in determining the feasibility of thermally active reinforced earth structures.

For this project, METER 5TM moisture probes will be used to evaluate changes in volumetric water content and temperature at discrete locations within a geosynthetic-reinforced soil layer during heat injection. Additionally, a METER KD2 Pro system will be used to determine non-isothermal relationships between the thermal properties of the soil and the degree of saturation. This set of instrumentation will be used to evaluate quantifying coupled heat transfer and water flow processes and related effects on the efficiency of geothermal heat in unsaturated soil deposits over time.

WAKE FOREST UNIVERSITY

MODELING SOIL-PLANT-ANIMAL FEEDBACKS TO UNDERSTAND “HOTSPOT” PERSISTENCE IN SERENGETI NATIONAL PARK

Physical and chemical properties of soils play a key role in mediating plant-herbivore interactions yet are often completely overlooked by ecologists. Serengeti “hotspots” are temporally stable swards of fast-growing, nutrient-rich grasses which attract populations of resident herbivores (zebra, gazelles) and generate heterogeneity within the ecosystem. Researchers have long been fascinated with hotspots but remain unable to explain the creation, maintenance, and spatial distribution of these unique microhabitats.

I will compare heavily grazed hotspots to neighboring non-hotspot sites and observe how specific soil characteristics vary with grazing intensity. I am especially interested in how the presence of grazers influences soil water potential and, ultimately, plant community composition and herbivore dynamics. Installing METER MPS-6 sensors and Em50 data loggers will allow me to monitor spatiotemporal variation in water potential in relation to grazing intensity. These data will serve as an integral component of a structural equation model (SEM) to provide a comprehensive mechanistic explanation for the persistence of Serengeti hotspots.

UNIVERSITÉ DE MONTRÉAL

IMPACTS OF DEGRADING PERMAFROST ON VEGETATION PRODUCTIVITY AND THERMAL AND MOISTURE REGIMES OF SOILS IN BOREAL FOREST LANDSCAPES

Boreal forest at the southern limit of the permafrost zone is especially vulnerable to a projected warmer climate. Widespread permafrost disappearance has been observed in northwestern Canada causing ground surface subsidence and a decline in forest cover. The resulting fragmented landscape is characterized by a high degree of spatial heterogeneity of soil thermal and moisture conditions as well as vegetation types.

Boreal forests in the Taiga Plains in northwestern Canada store a large amount of frozen soil organic carbon. Current soil thaw exposes this organic carbon to microbial decomposition but might also increase carbon uptake through increased plant productivity. A better understanding of the magnitude and dynamics of these carbon fluxes is important to assess potential feedbacks on the global climate.

In my doctoral research, I am using the eddy covariance technique and flux footprint models to study how the net exchanges of carbon, water, and heat between the land surface and the atmosphere are influenced by rapidly degrading permafrost. METER instrumentation allows continuous monitoring of vegetation status of the dominating land cover types and concurrent land cover type-specific monitoring of thermal and moisture dynamics. This information is essential to analyze integrated net ecosystem carbon dioxide exchange and its component fluxes gross ecosystem productivity and ecosystem respiration and to upscale these fluxes to regional scales.

University of Montana

HYDROLOGICAL AND ECOLOGICAL RECOVERY AFTER ROAD REMOVAL: INFLUENCE OF TREATMENT DESIGN ON ECOSYSTEM SERVICES

Despite the millions of dollars invested in the removal and restoration of legacy forest roads on public lands, there is considerable uncertainty among managers about the most effective road decommissioning method—particularly for promoting recovery of high value ecosystem services such as quantity and quality of water, nutrient cycling, and forest productivity.  At the core of management uncertainty is a dearth of research related to understanding the mechanisms of recovery for coupled above- and below-ground hydrological and ecological processes.

Because of the extensive road decommissioning and restoration efforts ongoing on the Nez Perce-Clearwater National Forest in north central Idaho, I have the opportunity to:

Location of Research: Lochsa Drainage, Nez Perce-Clearwater National Forest, Idaho County, ID.

• Develop integrated production functions to quantify how road removal may enhance ecosystem services, specifically quantity and quality of water and net primary productivity

UNIVERSITY OF WISCONSIN–MADISON

A WINTER WATER BALANCE TO INVESTIGATE NUTRIENT TRANSPORT FROM MANURE DURING FREEZE/THAW EVENTS

Phosphorus losses in agricultural runoff are a major environmental concern and thus are a key focus in manure management. Nutrient transport is sensitive to winter weather and the complex conditions of frozen soils, but as winter runoff generation and process-oriented information is limited, models and subsequent management guidelines are often not supported by data.

To investigate winter nutrient transport on manured fields, my objectives include quantifying a water balance to elucidate the underlying freeze/thaw mechanisms that control soil infiltration potential. Soil permeability will be tested in till versus no till corn fields with fall versus late-winter manure applications and unmanured controls. I will monitor runoff volume and nutrient load, snow, frost, soil moisture, and temperature.

Sublimation will be measured with VP-3 and DS-2 sensors and vertical soil water fluxes will be measured with MPS-2 water potential sensors. Data will inform prediction tools that evaluate nutrient loss from agroecosystems and improve agricultural sustainability by balancing environmental and economic viability.

UNIVERSITY OF CALIFORNIA AT BERKELEY

PREDICTING THE STABILITY OF RANGELAND PRODUCTIVITY TO CLIMATE CHANGE

Increased precipitation variability is predicted to be a consequence of anthropogenic climate change across rangeland systems. As precipitation more frequently departs from the historic range of variability, maintaining stable forage production despite increased climate variability will be a critical management priority in range agroecosystems.

A key mechanism that can lead to stability in forage production is compensatory dynamics, in which different species responses to climate fluctuations result in tradeoffs between functional groups over time. These tradeoffs should buffer overall forage production to climate variability. My dissertation tests the importance of compensatory dynamics for forage stability in an experimental field setting in which I manipulate rainfall availability and species interactions.

METER soil moisture probes and data loggers will allow me to characterize the treatment effects of this experiment and to parameterize models that predict rangeland response to climate change.

UNIVERSITY OF WISCONSIN

IRRIGATION AND CLIMATE IMPACTS TO THE WATER-ENERGY BALANCE OF THE WI CENTRAL SANDS

Pumping for irrigation in regions with strong ground-surface water connectivity can impact aquatic resources, leading to groundwater governance dilemmas. Recently stressed aquatic resources have created a dilemma between agricultural and aquatic stakeholders in the Wisconsin Central Sands, an ecological region with strong ground-surface water connectivity that has experienced changes in agricultural land use and climate over the past 60 years. My research goal is to determine how agricultural land use and climate change impact the regional water-energy balance of the Wisconsin Central Sands in response to scientific uncertainties identified by stakeholders.

My specific field objectives are to

Field-generated estimates of groundwater recharge and ET will parameterize and validate a dynamic, agroecosystem model, Agro-IBIS, simulating hydrological responses to climate and land use changes of the past 60 years. The water-energy budgets and water quantity/climate simulations will be shared with stakeholders in the Wisconsin Central Sands and future research questions will be generated through this forum.

• Estimate evapotranspiration (ET) using the METER SC-1 porometer to measure stomatal conductance along with micrometeorology, leaf area index, and gas exchange measurements

UNIVERSITY OF MARYLAND

ROOF-SCALE MODELING OF GREEN ROOF SUBSTRATE BLEND ON STORMWATER RETENTION AND PLANT-BASED WATER CYCLING

Green roofs are gaining popularity as stormwater management tools; however, reports concerning green roof performance are primarily based on small-scale platform studies (generally less than 20 square feet). The lack of real-roof performance data can be attributed primarily to expense and logistical concerns (i.e., some roofs are difficult or unsafe to access regularly).

I have established a relationship with a local green roof installation and management company who has been awarded the contract for a large green roof installation for a local government entity. The client wishes to collect data and monitor green roof performance. My project will equip a 30,000 square foot green roof for performance monitoring while simultaneously monitoring identical platform-scale systems for performance using appropriate METER moisture sensors and weather station instruments. Real roof performance data will be compared to platform performance data to determine if small-scale studies accurately predict real roof performance.

UNIVERSITY OF CALIFORNIA AT DAVIS

EFFECTS OF CHANGING SNOWPACK ON INVASIVE PLANTS IN MONTANE FORESTS OF CALIFORNIA

Montane forests are critical ecosystems to understand in the context of climate change because they represent spatial compressions of important climatic gradients and corresponding vegetation in a small geographic area. Decreases in depth and duration of winter snowpack expected in montane forests under climate change might facilitate spread of drought-tolerant invasive plants from lower elevations by lengthening the growing season.

My research investigates whether changes in snowpack can influence the population growth rates of two exotic shrubs (Scotch broom and Spanish broom) in the Sierra Nevada of California. Both species may be sensitive to earlier growing seasons brought about by decreased spring snow cover, because growth may occur via photosynthetically active green stems at soil temperatures as low as 4 °C . However, there is a possible tradeoff between earlier snowmelt and earlier soil moisture depletion that could lead to prolonged drought stress and reduced carbon gain. Preliminary data suggest that the more drought-tolerant shrub, Spanish broom, responds more positively than Scotch broom to reduced winter snowpack.

METER instrumentation will collect a comprehensive record of snow cover and soil moisture across a range of experimental snowpack treatments and forest canopy structures to document the interaction of those two factors and the mechanisms by which they can explain invasive plant performance.

UNIVERSITY OF VERMONT

ADAPTING TO CLIMATE CHANGE WITH LOW IMPACT DEVELOPMENT (LID) STORMWATER MANAGEMENT IN THE LAKE CHAMPLAIN BASIN

The goal of this research is to inform future design of Low Impact Development (LID) stormwater bioretention systems to provide optimal residence time, phosphorus adsorption and denitrification in the context of projected increases in precipitation in Vermont as a result of climate change. This research will investigate the mechanisms influencing greenhouse gas emissions and nutrient transformations at various depths in engineered soil media within eight bioretention cells at the newly constructed Outdoor Bioretention Laboratory at the University of Vermont. These systems will also be evaluated for their possible implementation in developing countries, which lack underground stormwater infrastructure.

UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN

FORESTED ALGIFIC SLOPES OF THE DRIFTLESS AREA: SOIL AND MICROCLIMATE EVALUATION AND MONITORING

Algific slopes are naturally occurring microclimatic ecosystems that are distributed across the Driftless Area of the Midwest (Cottrell and Strode 2005). Algific slopes are described as cold-air, north-facing colluvial slopes. Their unique microclimatological properties are due to geologic features fundamental to algific slope formation. Essentially, air is circulated across ice trapped in the fractured geologic substrate, which causes cool moist air to be vented on slopes during the warm months, thus effectively shaping local flora and fauna.

JOHNS HOPKINS UNIVERSITY

CRYPTIC METHANE EMISSIONS FROM UPLAND FORESTS

Methane is the second most important greenhouse gas after CO₂ but is far less understood. In the last 10 years, both lab experiments and satellite data have collected evidence that woody plants and forests are emitting methane to the atmosphere. Despite these new findings, upland forests are still considered sinks because organisms in their surface soils consume methane. It is also possible that methane could be leaking out of the deep soil through trees. This could result in a net methane source for an ecosystem that is currently considered a sink. Upland forests cover huge areas of the globe so there is a pressing need to resolve these issues and obtain accurate estimates of fluxes to be integrated into global climate models. Without new and accurate measurements, climate predictions will continue to include systematic flaws.

UNIVERSITY OF CALIFORNIA AT SAN DIEGO

INVESTIGATING DROUGHT RESPONSES IN THE CROP PLANT BRASSICA NAPUS

Drought is a major stress that reduces crop yields and will continue to be an increasing problem in the coming years as climate change and limited fresh water supplies lead to higher temperatures, desertification, and increased soil salinity. Abiotic stresses, including drought, elicit production of the plant hormone abscisic acid (ABA), which closes stomata through a complex signaling pathway, reducing the amount of transpirational water loss in plants.

I am using RNAi technology to knock down expression of negative regulator proteins in this pathway to assess whether drought responses in the crop plant Brassica napus (canola) can be enhanced without adversely affecting growth. The transformed plants will be grown under controlled drought conditions, with soil moisture content and stomatal conductance being monitored using METER instrumentation.

 MICHIGAN STATE UNIVERSITY

IMPROVING CARROT PROFITABILITY THROUGH THE INTEGRATION OF SLOW-RELEASE NITROGEN FERTILIZER

Improving nitrogen (N) use efficiency in vegetable production will not only be financially beneficial, but it will also improve environmental quality.  In Michigan, carrots are typically grown on very sandy soils and require frequent irrigation and multiple applications of nitrogen fertilizer over the course of their growing season.

My research focuses on  optimizing the synchrony of crop-N-demand with N supplied by fertilization through the use of slow-release-nitrogen fertilizer materials (SRN).  My overarching hypotheses are that the use of a polymer-coated urea (PCU) SRN material, in Michigan carrot production will

The potential benefits provided by the use of PCU in this system include reduced input costs, decreased non-renewable resource consumption, and minimization of environmental impacts caused by nitrate leaching.  METER data loggers and sensors that measure soil volumetric water content, temperature, and bulk electrical conductivity will help improve our understanding of conditions that regulate the release of N from the PCU.

Using METER data in combination with N extractions from soil samples, we hope to model N release as a function of moisture and temperature and to quantify the relationship between electrical conductivity and N release.  This information will be helpful for designing nutrient management programs for vegetable growers that are both profitable and environmentally friendly.

UNIVERSITY OF PITTSBURGH

EVALUATION OF GREEN STORMWATER INFRASTRUCTURE IMPACTS ON URBAN HYDROLOGY

Clarification of urban hydrologic budgets is needed to improve water management in complicated urban systems.  The aim of this research is to clarify changes in water inputs and outputs in an urbanized catchment and evaluate green infrastructure effectiveness in rerouting water to slower, subsurface flow paths.

Green infrastructure uses vegetation and soil amendments to reduce stormwater runoff at the source and promote infiltration and water storage.  Soil moisture sensors and water depth loggers, will be installed in two rain gardens and a control site at the Phipps Conservancy, located in Pittsburgh, PA. Sensors will continuously monitor soil moisture, water depth, temperature and conductivity at each site. Data collected will be used to characterize soil water dynamics and rain garden water storage.  Results from this study will clarify the benefits of green infrastructure as a stormwater management practice.

OREGON STATE UNIVERSITY

ESTABLISHING IRRIGATION CRITERIA FOR CORN LILY

In recent years, corn lily (Veratrum californicum) has garnered increased interest from the medical community because of its cancer fighting properties. Preliminary trials of the corn lily based drug IPI-926 (Infinity Pharmaceutical) on human subjects have yielded very promising results in the treatment of both basal cell carcinoma and pancreatic cancer. Establishing cultivation criteria for corn lily will be crucial in order to guarantee a steady supply of IPI-926.

The Oregon State University Malheur Experiment Station (MES) has conducted drip irrigation trials on corn lily for the past two growing seasons with the aim of characterizing the range of soil water tension that produces maximum corn lily growth. METER instrumentation will be used to measure soil water tension and soil moisture content in each of five treatments in the irrigation trial plots.

UNIVERSITY OF GEORGIA

INVESTIGATING THE LACK OF TRADE-OFF BETWEEN DROUGHT RESISTANCE AND MAXIMUM PRODUCTIVITY

Changes in global precipitation patterns are predicted to affect plant productivity in both natural and agricultural systems throughout the world. One of the major concerns of these precipitation changes is that some species will face increased water limitations causing decreases in plant productivity.

It has been demonstrated that species which are more drought resistant tend to have a low maximum productivity when grown under well-watered conditions. However preliminary evidence suggests that Helianthus porteri, a species which is found on the hot, dry granite outcrops of the Southeastern U.S., does not exhibit this tradeoff. Comparing drought resistant responses of H. porteri to its two closest relatives, H. agrestis and H. carnosus, which inhabit moist soils, can provide useful information for future agricultural.

My assessment of these species, especially H. porteri, will expand efforts to mine wild Helianthus species for drought resistance traits for agricultural purposes. My goal is to provide insight into which traits may be useful for enhancing agricultural productivity in areas where water limitation is expected to become problematic in the future.

UNIVERSITY OF GEORGIA

CALIBRATING LEAF WETNESS SENSORS TO MEASURE DEW QUANTITY IN A STUDY OF AMMONIA VOLATILIZATION FROM SURFACE-APPLIED BROILER LITTER

Large quantities of broiler litter are produced annually from commercial chicken production.  It is commonly used as fertilizer and is a good source for plant-available nitrogen in pastures and crops.  The amount of plant-available nitrogen and nitrogen loss to the atmosphere through ammonia volatilization is dependent on soil characteristics, application rates, and environmental factors.  Understanding the importance of rain, relative humidity, temperature, soil moisture, and dew deposition on volatilization and other nitrogen transformations in litter will lead to a better understanding of nitrogen applied to pasture and modeling for more precise application rates.

Read more about leaf wetness sensors and dew deposition

Washington State University

MONITORING N LEACHING UNDER ORGANIC FARM MANAGEMENT

Nitrogen is the most vital nutrient used in agricultural systems and contributes greatly to the economic viability, sustainability, and improvement of cropping systems throughout the world. Its management however has been linked to myriad of global problems ranging from groundwater pollution as a result of N leaching beyond root zones, eutrophication as result of its losses in surface runoff/erosion and its huge contribution to global climate change in the form of N20 emission.

Optimizing N management in organic systems is a challenge because of high N sensitivity and the unpredictability of N mineralization from organic fertilizers and soil organic matter. Also application of compost and organic fertilizers to increase soil fertility, which is prevalent in organic systems may increase the potential for unintended groundwater contamination by nitrate leaching. There is thus a need for evaluation of the impact of organic farming practices on soil organic matter, greenhouse gas emissions, and nutrient fate.

Using the METER Drain Gauge G3, I will be monitoring the flux of water and nitrogen draining from the vadose zone to help determine the nutrient availability and effects of common inputs, crops, and practices used on N leaching in five organic focus farms located in various parts of Washington state. Data from this research will help us to parameterize and evaluative predictive models for improvement of organic fertilizer management.

UNIVERSITY OF WYOMING

IMPROVING CROP GROWTH UNDER DROUGHT: AN APPROACH USING GENETICS AND THE PRECISE MEASUREMENT AND CONTROL OF SOIL MOISTURE

There is potential and impetus to develop crops either through breeding or genetic engineering that have traits that allow for greater growth under conditions of drought. While moving through a plant, much of the resistance that water experiences is from passing through membranes in the leaves and roots. Plants are able to decrease their overall resistance to water flow by creating proteins, called aquaporins, that insert themselves into these membranes and act as water channels. Crop genotypes that have a greater capacity to use these proteins to decrease their overall resistance to water flow may be able to assimilate carbon for a greater amount of time each day before their water potentials reach the point where their stomata need to close.

Genotypes of an important crop, rapeseed oil (Brassica rapa), have been identified with varying levels of aquaporin function. These genotypes will be grown under carefully controlled combinations of soil and atmospheric drought in a custom-made, automated system using METER soil moisture probes, to determine if this trait allows crops experiencing a drought to fix greater amounts of carbon and hence grow faster.

UNIVERSITY OF BRITISH COLUMBIA

BIOCHAR IMPACTS ON SOIL WATER DYNAMICS AND LEACHING IN A DOUGLAS FIR FOREST SOIL

Biochar is a very stable form of organic carbon (C) produced by pyrolysis of biomass. Its use in agricultural soils has been suggested as a means for reducing nutrient leaching losses and greenhouse gas emissions while increasing crop yields and soil carbon storage.

I seek to evaluate the potential use of biochar derived from Douglas fir and applied to Douglas fir forest soils to improve soil water dynamics and soil C storage. METER water potential sensors and GS3 sensors will be installed at a well-established research site to measure soil water characteristics for four treatments:

Soil cores taken from biochar treated field soils will be brought to the METER laboratories (Pullman, WA) where soil water characteristics curves will be determined using the METER Hyprop and WPC4. By focusing on Douglas fir we are representing the forest type with the largest latitudinal range of any commercial coniferous forest in North America. Results of this study are anticipated to help in directing forest harvesting away from dwindling areas of old-growth forest by evaluating strategies for improving the sustainability of Douglas fir production within existing managed forest areas.

• Biochar plus fertilizer each at aforementioned application rates
• Control

UNIVERSITY OF GUELPH

ANALYZING AND IMPROVING THE WATER TABLE FLUCTUATION METHOD OF ESTIMATING GROUNDWATER RECHARGE

Groundwater recharge (GWR) measurements in urban and rural areas are crucial for many applications, including understanding the spatial and temporal dynamics of groundwater availability and developing source water protection guidelines. Substantial gaps exist in our knowledge of GWR and accurate estimates are elemental for the characterization of the hydrological budget.

A novel technique is under development so that recharge (R) can be quantified accurately at the local scale on a five minute basis (averaged hourly) year-round using the water table fluctuation (WTF) method in combination with the soil water budget monitoring. The ability to measure R frequently over the entire year for multi-years is critical, as often substantial R occurs over a short time period of robust dynamic. The expected outcomes and the significance of the project are:

Obtaining GWR measurements at the local scale on a year-round basis, which are currently scarce or even completely lacking for many regions of Ontario and thus would provide a valuable database for guiding development or any policy requiring GWR Using this database to calibrate and test estimates of the spatial and temporal variability in regional-scale (watershed scale) GWR from approximate statistical techniques or deterministic means using, for example, precipitation and soil texture Providing guidance on how to supplement equipment at preexisting weather stations to measure GWR at the station. Guidance might include how many water-table wells, piezometers, soil water content and temperature sensors, tensiometers, and Drain Gauges need to be installed to estimate GWR within a desired confidence interval.

San Francisco University

RECHARGE RATES BENEATH LOW-IMPACT DESIGN RAIN GARDENS AND THE INFLUENCE OF EL NIÑO SOUTHERN OSCILLATION ON URBAN COASTAL GROUNDWATER RESOURCES

Global groundwater resources in urban, coastal environments are highly vulnerable to increased human pressures and climate variability. Impervious surfaces, such as buildings, roads, and parking lots prevent infiltration, reduce recharge to underlying aquifers, and increase contaminants in surface runoff that often overflow sewage systems.

To mitigate these effects, cities worldwide are adopting low impact design (LID) approaches that direct runoff into natural vegetated systems, such as rain gardens that reduce, filter, and slow storm water runoff and are hypothesized to increase infiltration and recharge rates to aquifers. The effects of LID on recharge rates and quality is unknown, particularly during intense precipitation events for cities along the Pacific coast in response to inter-annual variability of the El Niño Southern Oscillation (ENSO).

Using METER water potential and soil moisture sensors, I will collect and monitor soil, hydraulic, and geochemical data to quantify the rates and quality of infiltration and recharge to the California Coastal aquifer system beneath a LID rain garden and traditional turf-lawn setting in San Francisco, CA.

The data will be used to calibrate a HYDRUS-1D model to simulate recharge rates under historical and future variability of ENSO. Understanding these processes has important implications for managing groundwater resources in urban, coastal environments.

WASHINGTON STATE UNIVERSITY

COVER CROP INFLUENCES ON NITRATE LEACHING OVER WINTER

Potato production in Skagit Valley, Washington requires the use of fertilizer inputs to be profitable. Winter rainfall may leach labile nutrients leading to environmental issues. Cover crops hold promise in their ability to decrease nutrient leaching by increasing organically bound elements.

This research will employ 5TE soil moisture, temperature and EC sensors in conjunction with FullStop Wetting Front Detectors to measure water and solute flux for soils sown with or without winter cover crop mixtures. Our mission is to provide local organic and conventional producers with site-specific and sustainable production options. Characterizing which cover crops are best as catch crops will address grower apprehension and facilitate effective utilization.

 UNIVERSITY OF CALIFORNIA, SANTA BARBRA

UNDERSTANDING PROCESSES UNDERLYING TREE MORTALITY IN A CALIFORNIAN COASTAL PINE FOREST

Forests along the foggy coastline of California are likely to experience a warmer and possibly less foggy future.  Because summertime fog augments the water supply to forests during a time of year when conditions are otherwise warm and dry, less fog water input will likely place trees at higher risk of water stress and drought-induced mortality.

This study seeks to understand how variation in fog-water inputs impacts the physiological state of trees in a Bishop pine (Pinus muricata D.Don) stand located on Santa Cruz Island in Channel Islands National Park.  Sara will conduct a field-based experiment where she alters plant-available soil water to these trees by manipulating fog drip to the soil surface.  The goal of this study is to better understand how fog-water inputs influence the water budget of coastal forests and thus to enhance our ability to predict how coastal forests may respond to climate change.

CLEMSON UNIVERSITY

PHYSIOLOGICAL AND MORPHOLOGICAL RESPONSES OF AN EPIPHYTIC FERN TO NUTRIENT SUPPLY

The availability of nutrients and water can largely determine the distribution of plants.  Plants that can thrive under a variety of nutrient and water levels have higher morphological and physiological plasticity and thus a wider distribution than plants that are more specialized to particular conditions.  Pleopeltis polypodioides is an epiphytic fern (i.e., a plant that lives non-parasitically in the canopy of trees) whose distribution includes the hardwood forests of the southeastern  United States and the tropical rain forests of Central and South America.  The ability of this plant to span such a wide distribution may reside in its ability to tolerate varying levels of nutrient and water supply.

I propose to examine the morphological and physiological characteristics of P. polypodioides to varying degrees of nutrients and moisture in both South Carolina and Costa Rica.  From previous experiments, I found that when P. polypodioides was grown in high water without added nutrients, plants showed evidence of photoinhibition resulting in lowered growth and photosynthetic rates.  When nutrients were added, there was no evidence of photoinhibition; rather, there was an increase in the photosynthetic and growth rates.

I am proposing to test the hypothesis that in wet environments, P. plypodioides is restricted to habitats in the canopy with high nutrient content such as in canopy soil in order to mitigate the effects of photoinhibition.  I will measure morphological and physiological characteristics of P. plypodioides to varying nutrient and water supplies such as stomatal conductance, specific leaf area, and the concentration of nitrogen and phosphorus in leaf tissue.  Given that P. polypodioides can inhabit a diversity of habitats from oak trees in South Carolina to emergent canopy trees in Costa Rica suggests a potentially unique ability among ferns to tolerate a wide variety of environmental conditions.

UNIVERSITY OF SOUTH FLORIDA

ASSESSING INTERMITTENT FLOW IN SINKHOLES AND RECHARGE PATTERNS IN COVERED-KARST TERRAIN

A better understanding of groundwater flow is critical for improved water resource management in complex covered-karst environments.  Flow volume through vertical sand-filled collapse columns can determine whether a wetland will drain or whether lake levels and water tables will fall, especially where aquifers are heavily pumped.  Conflict rages over the competition for water resources, thus better understanding of sinkhole behavior and effective monitoring methods of near-surface groundwater flow are extremely desirable.  It is hypothesized that self-potential measurements reflect transitions between three flow regimes: fast-flowing, deeply plugged at shallow depths that behave as though no sand column is present.

Testing this intermittent flow hypothesis requires measuring moisture movement and matric potential changes during SP fluctuations.  An effective protocol for using hydrological sensors and SP to monitor sinkhole-associated flow will be established.  In addition, soil moisture sensors at conduits and at key hydrological, topographical, vegetative, and insolation locations will separate signals due to streaming potential from ET, root suction, and anisotropic terrain effects and confirm or deny usefulness of SP for analyzing groundwater movement.

Understanding water movement is as important in the 21st century as finding oil was in the 20th.  It is not just a matter of protecting wetlands, lakes, and streams but managing a resource that will be used competitively for transportation (fuel cell), nourishment, and recreation.  This work also addresses locating drain fields and well fields and may help distinguish sinkholes from shrink-swell soils as subsidence sources.  This study will practically assess SP as a tool for mapping vadose zone flow.

NORTH CAROLINA STATE UNIVERSITY

ENVIRONMENTAL AND PHYSIOLOGICAL RESPONSES TO STRESS INDUCTION IN TWO V. VINIFERA CULTIVARS IN NORTH CAROLINA

As North Carolina wine grape production intensifies, the importance of water management must be addressed.  Grape yield and composition, and consequently wine quality, are profoundly influenced by the water regime under which the grapes were produced.

Despite the importance of water management, little research pertinent to this topic has been carried out in North Carolina’s primary wine grape region, the Yadkin Valley Appellation.  This region has unique soils and climate and may differ considerably from other established wine regions where water management research has been completed.  While preliminary findings suggest that precipitation amounts exceed evapotranspirative demand in this region, some water stress is desirable for quality grapes, as excess available water negatively affects grape quality.

The primary objective of this research is to determine the status of key environmental and physiological variables at which desirable stress levels are attained in two hydraulically dissimilar v. vinifera cultivars, Grenach and Syrah.  We will exclude water from vines in these two cultivars, and use METER’s water content sensors, data loggers, and steady-state porometer to monitor soil and plant parameters as water stress is induced.  This information will assist growers in water management decisions and will be used to assess the feasibility of attaining adequate stress levels for quality grape production in this region.

UNIVERSITY OF MARYLAND COLLEGE PARK

LOW-RESIDUE WINTERKILLED COVER CROPS FOR NO-TILL VEGETABLE PLANTING

Despite the known soil quality and environmental benefits of both cover crops and reduced tillage, integrating cover crops and eliminating tillage for the earliest spring vegetables remains problematic in the Northeast and Mid-Atlantic United States.  Many traditional, high-residue cover crops exacerbate the problem of cool, wet soils in spring and can immobilize nitrogen for the subsequent crop.  Alternative, low-residue winter killed crops have the potential to provide environmental and soil quality benefits such as nutrient capture, erosion prevention and organic matter addition while facilitating early planting in spring without necessitating tillage.

This research will investigate the use of alternative cover crops such as forage radish, phacelia, black oats and lablab bean for no-till spring planting of vegetables.  Using METER 5TE sensors, we will monitor soil moisture and temperature to determine appropriate planting dates and we work to establish a relationship between pore water EC and nitrate concentrations to monitor the decomposition of cover crops and their ability to provide N to the subsequent crop.

UNIVERSITY OF CALIFORNIA, DAVIS

TESTING INNOVATIVE IRRIGATION METHODS TO INCREASE WATER USE EFFICIENCY

Alternative irrigation methods that use less water but produce high yields contribute to agricultural sustainability. This project focuses on the promising partial root drying (PRD) technique used in practice as alternate furrow irrigation to reduce water applied and increase crop water-use efficiency (yield/water applied, WUE) of processing tomatoes in California.

Information is now available on general crop physiological responses to the PRD technique, but strategies for reliable management need to be tested for individual crops. Alternate furrow irrigation consists of selectively watering only every other furrow. Each bed receives water on just one side and alternates the sides/furrow at each irrigation. Using half of the furrows in a field can reduce the volume of water applied, potentially without a decrease in yield.

Soil moisture and plant water status monitoring become crucial in timing each irrigation to prevent severe water stress and yield reduction but are limited by the capacity to take frequent measurements in a non-destructive fashion. Using the METER EC-5 soil moisture sensors at different growers’ fields, instant readings will be taken often enough to monitor soil water availability at two different depths. These data will be related to leaf conductance measurements from the SC-1 leaf porometer to show irrigation treatments that are water-use efficient and produce high yields. We will also analyze how soil moisture affects nitrogen leaching, canopy growth and light interception, WUE, yield, and fruit quality in every or alternate furrow irrigation regimes.

SAINT LOUIS UNIVERSITY

INFLUENCE OF SOIL PROPERTIES ON THE REVERSAL OF DESERTIFICATION

The desertification of arid grasslands around the world is seen as largely irreversible.  However, recent work has documented recovery of perennial grasses in long-term livestock enclosures at four desertified sites.  At one such site, changes in vegetation were concomitant with increased water infiltration and soil nutrients.

Based on these data, I proposed the following mechanism for reversal of desertification:  in the long-term absence of livestock, water infiltration rates increase via release from compaction, which decreases erosion and allows soil nutrients accumulate to a level that is favorable to perennial grass re-establishment.

To test this model, I am collecting data from additional long-term livestock enclosures at sites with and without grass recovery.  These data will allow us to draw more comprehensive conclusions about the dynamics of desertified systems, and the potential for restoration of arid range lands.

COLORADO STATE UNIVERSITY

QUANTIFICATION OF CONSUMPTIVE USE AND RETURN FLOWS IN IRRIGATED AGRICULTURE

As rapid municipal growth occurs in the Colorado Front Range and other water-limited areas of the United States, increasing pressure is put on farmers to transfer water rights.  As an alternative to permanent water rights transfers, Kendall’s research investigates the ability of producers to reduce seasonal consumptive use and optionally lease unused water to cities.

Kendall will use the METER Watershed Characterization Package to monitor three sensor arrays in a furrow irrigated corn field.  Data collected at these sites will help compute all components of the water balance.  This sampling method could potentially be used by individual producers as a low-cost method to quantify both evapotranspiration and return flows.

OKLAHOMA STATE UNIVERSITY

EFFECTS OF MARGINAL LAND CONVERSION TO BIO-ENERGY FEEDSTOCK PRODUCTION ON THE WATER CYCLE

Recent government mandates requiring increased production of bio-fuels to improve sustainability of the nation’s fuel supply and reduce carbon emissions could affect the water cycle both during and after energy crop establishment.  Switchgrass, a leading choice for biomass production has deeper roots than dominant mixed-grass prairie species.

We will use paired watersheds in Woodward, Oklahoma to determine how switchgrass establishment and production will affect each component of the water cycle.  The G.A. Harris Fellowship will provide METER Drain Gauge Lysimeters to determine deep drainage on each watershed and improve our understanding of both the baseline water cycle of this landscape and the water budget associated with a switchgrass monoculture.

 IOWA STATE UNIVERSITY

CLIMATE CHANGE EFFECTS ON TROPHIC INTERACTION IN MONTANE MEADOW SYSTEMS

Climate change is likely to impact many biological systems.  This study will quantify how modification in the timing of key biological events could affect a montane meadow ecosystem.  In this project, Jill will manipulate snow cover and temperature to mimic the effects of predicted climate change.  She will then test the interactions between soil moisture, soil temperature, and air temperature on emergence and survival of Parnassius clodius butterflies and their host plants, Dicentra uniflora.  The results will provide insight into the interactions of butterflies and their host plants and will be used as a proxy for understanding climate change impacts in other ecological systems.

UNIVERSITY OF WASHINGTON

WATER-HOLDING CAPACITY AND TEMPERATURE PATTERNS OF CANOPY SOILS IN AN OLD-GROWTH SITKA SPRUCE FOREST OF WASHINGTON STATE

Sitka Spruce tree crowns contain large accumulations of organic matter known as “canopy soil”.  These accumulations provide substrate and habitat for a broad community of plants, insects, and other arboreal species.  Using tree-climbing techniques, moisture and temperature sensors will be installed in the canopy soils of spruce trees of an old-growth stand of the Olympic Peninsula, Washington.

This study will characterize for the fist time environmental conditions associated with soil mats within the crown of spruce trees, providing a framework for understanding the distribution and activity of epiphytic plants, nutrient dynamics and associated canopy organisms.

IOWA STATE UNIVERSITY

INVESTIGATION INTO THE SPATIAL VARIABILITY OF DEW AT FIELD SCALE

Investigations into the spatial and temporal variability of dew have implications for both plant disease management and remote sensing of soil moisture.  In this study, the process of scaling point measurements of dew to canopy scale will be investigated by determining the contribution of LAI for regions in the canopy with the highest and lowest dew amounts to the total LAI of the canopy.  Leaf wetness sensors will be used to determine where in a soybean canopy the greatest dew duration (and amount) occurs.  Investigation at locations around a field will be examined for variation of dew within a field.

 UNIVERSITY OF WISCONSIN

THERMAL CONDUCTION PHENOMENA OF COMPACTED FILL FOR SUSTAINABLE ENERGY PRACTICE

Maximizing heat flow around high voltage, high ampacity cables in wind energy collector trenches and in shallow geothermal exchange trenches is necessary for efficient cyclic heating and cooling processes in compacted, engineered trench back-fill soil.  Research into the physical structure of compacted fill and theoretical constraints as related to heat input rate and thermally driven moisture flow is limited in the unsaturated state.  To transition from establishing soil thermal values for design by rules of thumb to using empirical correlations based on science and thermal measurements, a database of measured thermal properties for a comprehensive collection of soil types at variable compaction conditions will be compiled and investigated for correlations of soil thermal properties with physical properties.

BRIGHAM YOUNG UNIVERSITY

MEASURING DEEP DRAINAGE IN THE SOIL AS A RESPONSE TO GRAZING AND RAINFALL MANIPULATION

Climate change in the western United States is predicted to cause longer intervals between rainfall events and greater volume of rainfall in single events.  Grazing will likely interact with climate change to influence the soil water balance.  The instruments provided by this grant will measure changes in deep drainage related to rainfall manipulation in paired grazed and ungrazed treatments.  Rainfall manipulation and grazing may result in greater water loss through deep drainage or may improve water availability in the root zone.  The amount of water available for plants and soil bio-geochemical processes in a single year may change even if total annual precipitation remains constant.

KANSAS STATE UNIVERSITY

CANOPY ARCHITECTURE AND RADIATION USE EFFICIENCY IN SORGHUM

This study investigates the influence of canopy architecture on sorghum radiation-use efficiency.  RUE was calculated as the ratio of above-ground biomass accumulation to cumulative intercepted photosynthetically active radiation (IPAR).  Accupar LP-80 Ceptometer measurements of PAR above and below a crop canopy provide measures IPAR and leaf area index.  Preliminary results showed:

Lines differed in apparent RUE, which increased with average internode length Positive correlation between RUE and water use efficiency (biomass produced per unit crop water use) The increased productivity was due to increased radiation use efficiency rather than capture considering the similarity among lines in IPAR

UNIVERSITY OF CALIFORNIA, DAVIS

MODELING ROOT DISTRIBUTION AND NUTRIENT UPTAKE IN ALMONDS

To optimize nutrient use efficiency in fertigated almond it is essential that fertilizers injected into the irrigation system are provided at the optimal concentration and time to ensure that deposition patterns coincide with maximal root nutrient uptake.  The objective of the project is to instrument almond trees with 5TE water content devices to monitor ion and water movement to provide almond specific data to input in Hydrus 2D/3D model.  The goals are to determine root distribution, water and solute movement and dynamics of plant nutrient uptake.  These parameters, and the subsequent optimization of Hydrus performance, will be used to develop best fertilization management tools for almond growers.

UNIVERSITY OF MAINE, ORONO

ALTERNATIVE WEED MANAGEMENT STRATEGIES FOR ORGANIC CEREALS: ENHANCED CROP-WEED INTERFACE AND PHYSICAL WEED CONTROL

There are two innovative and opposing strategies to improve weed management in cereals grown with minimal or no herbicide inputs:

By measuring crop canopy development over the growing season, Lauren hopes to characterize how the dynamics of leaf area index (LAI) vary between planting strategies and determine how this correlates to weed suppression.

University of Virginia

FOG, AEROSOLS, AND NUTRIENT CYCLING IN THE NAMIB DESERT

The Namib Desert on the Southwestern coast of Africa is hyper-arid in terms of rainfall but experiences frequent coastal fog events.  The fog has been suggested to provide sufficient water to certain plants which are endemic to the Namib, some of which occur only in the fog zone (up to 60 km inland).  The G.A. Harris fellowship will be used to set up five fog monitoring stations along a climate gradient in the central Namib utilizing leaf wetness, air temperature and relative humidity measurements along with solar radiation and soil parameters (moisture, temperature, and electrical conductivity).  Stable isotope analysis of samples will also be used to help quantify the amounts of fog, groundwater, and soil water that plants utilize.

UNIVERSITY OF COLORADO

MEASURING CARBON SEQUESTRATION PROCESSES IN SUBALPINE FOREST USING WIRELESS SENSOR ARRAYS

Scale matters in modeling soil respiration rates.  This study deploys a suite of soil respiration and environmental sensors at the Niwot Ridge AmeriFlux research site to explore at what scales (temporal and spatial) drivers of soil respiration affect the respiratory flux of CO₂ from the forest floor.  This project will test our capabilities to measure soil environmental dynamics across small spatial scales and at high temporal frequencies.  We will develop new strategies for sensor deployment and the use of wireless technology to sustain high-frequency data collection and archiving in a remote location.

SARA BAGUSKAS, UC SANTA BABARA

Ecological interactions between epiphytic macrolichen (Ramalina mensiesii) and fog on Santa Cruz Island, California

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JUSTIN BECHNELL, UNIVERSITY OF MINNESOTA

Soil moisture and carbon uptake in restored tropical dry forests

ROBERT KEEFE, UNIVERSITY OF IDAHO

Model-based optimization of seed germination timing

 TONI SMITH, BOISE STATE UNIVERSITY

Spatiotemporal variations in soil water and their effects on carbon storage and cycling in a semi-arid foothills watershed

JAMES PAREJKO, WASHINGTON STATE UNIVERSITY

Determining the ecology and biogeography of phenazine-producing flourescent Pseudomonas spp. in the wheat rhizosphere

JONGYUN KIM, UNIVERSITY OF GEORGIA

Modeling water and fertilizer use of greenhouse crops for efficient irrigation