Irrigated land accounts for 40% of our food supply, and salts impact yields on about one-fifth of those acres. All irrigation water contains at least some salt. If salts are allowed to build up around the root zone of a crop, they injure plants, reduce yields, and even change soil structure causing long-term damage to the land itself. In order to preserve the productivity of irrigated land, it is important to learn how to manage salts.
The steps to managing salts are:
- Measure how much salt is currently in the soil
- Determine how much salt we are adding through irrigation
- Monitor continuously to manage salts as we irrigate
Electrical conductivity (EC) is the key to making these measurements. Pure water does not conduct electricity, but most water, even tap water, has enough dissolved salts to be conductive. Because the concentration of salts in water directly affects its conductivity, the measurement of electrical conductivity is a very effective way of measuring salt concentrations in soil water.
For in-depth information on how to measure electrical conductivity in soil, download the app guide: “Soil electrical conductivity: a beginner’s guide to measurements.”
Topics covered include:
- Why measure EC?
- Salt and plants. What’s the problem?
- More than one way to measure EC
- Application 1: minimizing salt buildup
- Application 2: calculating leaching fraction
- Application 3: tracking nutrients in the root zone
- Appendix 1: collecting data for EC