Examination of Irrigation Water Quality and Role in Mississippi Soybean Production
Investigators
Objectives
- Sample irrigation water throughout the growing season and at farms across the Delta utilizing both surface and groundwater to capture the spatial and temporal variability of irrigation events. Samples will be measured for micro and macro nutrients in water, as well as pH, conductivity, dissolved oxygen (DO), and temperature to determine water quality at the time of irrigation application in soybean fields
- Evaluate the variability in water quality and identify potential components or concentration levels that may be detrimental to soybean growth based on the literature
- Conduct saturated paste tests of soils at each farm with irrigation water at the beginning and end of the growing season to determine changes in dissolved nutrients, metals, and salts. Evaluate soil physical, chemical and biological properties in irrigated and non-irrigated soils at study sites
- Collect yield data from participating farms to evaluate relationships between source water type and yield. Through this research we will estimate the range in water quality conditions of irrigation water for Mississippi soybeans throughout a season of measurements.
Expected End Results
Approximately 350,000 acres of soybeans are irrigated in Mississippi. Producers typically know rates of fertilizer and pesticides added to their fields, but they are unaware of what is being added to their fields via irrigation. With estimated high phosphorus content in the MRVAA, fertigation is likely occurring. However, high levels of iron may interfere with phosphorus availability in soils and for the soybean crop. There is a need to understand the role of irrigation in nutrient budgets within Delta agroecosystems. In addition, this work will help identify water quality components that could be diminishing soybean yields in the Delta and aid developing mitigation strategies.