Modern Geospatial Technologies for Cotton Irrigation Management

Several geospatial technologies are now available for applications in precision cotton irrigation, including soil property mapping, remote imaging from drones, spatial crop evapotranspiration modeling, and site-specific irrigation application technology. However, the potential contribution of different geospatial technologies toward improving crop production and water use efficiency remains unclear. The objective was to determine agronomic outcomes using a cascade of increasingly complex geospatial technologies to assist cotton irrigation decisions and applications. The four treatments from least to greatest complexity were 1) an FAO-56 water balance model with field-average soil data, 2) #1 applied geospatially with site-specific soil information, 3) #2 with FAO-56 basal crop coefficients (Kcb) estimated from weekly drone images, and 4) #3 with irrigation applications via commercial, map-based, site-specific irrigation technology. Results on irrigation amounts, yield, and water use efficiency will be presented for field investigations during the 2019 and 2020 cotton seasons at Maricopa, Arizona.