Topics Concerning Water Stress
Water stress is one of several factors that can reduce crop yield and quality. Under-irrigation results in plant water stress, while over-irrigation leaches nutrients and other chemicals out of the root zone. Maintaining root zone water content is essential to any crop production operation.
- Methods to Monitor Soil Moisture, publication A3600-02, is a University of Wisconsin-Extension publication about how to monitor soil moisture. Read or download it here, or at the UW-Extension Learning Store website.
- Irrigation Management in Wisconsin, publication A3600-01, is a University of Wisconsin-Extension publication about crop irrigation. Read or download it here, or at the UW-Extension Learning Store website.
More Resources on Water Stress and Monitoring Soil Moisture:
Below are more resources on water stress and monitoring soil moisture. Click on the title of each publication or resource to go to the link and read or download the information.
- Irrigation Monitoring Using Soil Water Tension, by C. Shock, F. Wang, R. Flock, E Feibert, C Shock and A Pereira, Oregon State University Extension Sustainable Agriculture Techniques Publication EM 8900
- Tensiometers for Soil Moisture Measurement and Irrigation Scheduling, by A. Smajstrla and D. Harrison, University of Florida Extension publication CIR487.
- Tensiometer Use in Scheduling Irrigation, by M. Alam and D. Rogers, Kansas State University Agricultural Experiment Station and Cooperative Extension Service publication L-796 Irrigation Management Series.
When to Stop Irrigation:
When Can One Stop Irrigating! Crop “ET” Slowly Reduces as Maturity Nears – Jerry Wright, Irrigation Engineer-Emeritus, University of Minnesota, 2014.
When is the Best Time to Stop Irrigating?, Duane R. Berglund, Extension Agronomist, North Dakota State University, 2001.
- A list of equipment suppliers for soil moisture management is available here. The inclusion of equipment manufacturers and/or product names are for example purposes only and does not constitute endorsement or condemnation if not included by the University of Wisconsin or University of Wisconsin-Extension.
Vendor Links to Sensor Installation Videos:
- A list of links to installation videos produced by vendors of soil moisture sensors is available here. The inclusion of equipment manufacturers and/or product names are for example purposes only and does not constitute endorsement or condemnation if not included by the University of Wisconsin or University of Wisconsin-Extension.
Soil Water Release Curves:
- Soil moisture is commonly measured using soil water tension and dielectric methods. Soil tension measures the attraction or adhesion of water to soil particles or the force of surface tension pulling water into soil pores. Dielectric methods measure the storage and dissipation of the electrical and magnetic energy of the soil. The inter-relationship between these two measurement methods is defined by the soil water release (also called retention) curve (SWR curve). The SWR curve is influenced by soil texture and organic matter content, both of which can vary significantly even within a field.
- Below are 3 different sets of soil water release curves (SWR) for 3 different soil texture groups (sand, loam, clay). These SWR curves approximately define the relationship between soil tension and volumetric water content within each texture group. If exact values are needed, a site specific SWR curve needs to be developed. Click on the title below to see and download the graphs.
Computer Software Program for Scheduling Irrigation:
- The Wisconsin Irrigation Scheduling Program (WISP) is a free, research-based program that uses a water budget approach to irrigation scheduling much like balancing a checkbook. Find the program here.