Variable Rate Irrigation for Cotton and Maize

Irrigation using overhead sprinkler systems (primarily center pivots) is commonly used for cotton (Gossypium hirsutum L.) and maize (Zea mays L.) production in the southeast USA. Although technology for variable rate water application is available, it is not widely used. Methods to develop prescriptions in-season in response to changing crop conditions are needed to move this technology forward. The objective of this research was to evaluate the potential of using normalized difference vegetative index (NDVI) to estimate crop coefficients for development of spatial irrigation prescriptions.