Crop irrigation which results in high water use efficiencies typically uses science-based irrigation scheduling tools to determine irrigation application timing and quantities. Although a large variety of sensors are available for measuring soil moisture status, there are a few easy-to-use irrigation scheduling tools which provide a yes/no irrigation decision or recommend how much water should be applied to return the soil profile to an optimal soil moisture condition. The work described here developed a method which uses soil water tension data from soil moisture sensors and the van Genuchten model to provide irrigation scheduling recommendations. The strength of the method is that it can use data readily available from USDA-NRCS soil surveys to predict soil water retention curves and calculate the volumetric water content and soil water tension of a soil at field capacity. Those parameters are then used to translate measured soil water tension into irrigation recommendations which are specific to the soil moisture status of the soil. The method was validated by comparing its results to other published methods and with continuous soil water tension data with multiple wetting and drying cycles from six fields in southern Georgia, USA. Finally, the model was incorporated into a web-based irrigation scheduling tool and used in conjunction with a wireless soil moisture sensing system to schedule irrigation in a large commercial field during 2015. By the van Genuchten model, we used about two thirds of the irrigation water and produced about the same yields as a commonly used yes/no irrigation decision tool. The presented method can be used to build resiliency to climate variability because it provides growers with data which they can use to make informed decisions about managing their water resources.
|Number of pages||10|
|Journal||Agricultural Water Management|
|State||Published - Oct 1 2016|
Bibliographical noteFunding Information:
Funding for this project was provided by the NOAA Regional Integrated Sciences and Assessments (RISA) Program through the Southeast Climate Consortium (SECC) , the USDA-NRCS Conservation Innovation Grant (CIG) Program through the Flint River Soil and Water Conservation District, the Southern Peanut Research Initiative (SPRI) Cotton Incorporated, the Georgia Cotton Commission, and by Hatch and State funds allocated to the Georgia Agricultural Experiment Stations. The authors would like to acknowledge Mike Tucker, Herman Henry, and Rodney Hill for their contributions to sensor installation and data collection. The authors are grateful to the anonymous two reviewers for their comments on the manuscript.
- Field capacity
- Permanent wilting point
- Soil water tension
- Volumetric water content
ASJC Scopus subject areas
- Agronomy and Crop Science
- Water Science and Technology
- Soil Science
- Earth-Surface Processes