Impact of local weather variability on irrigation water use in Georgia

Abstract

Irrigation is often used to offset the impact of rainfall variability on crop yield and to reduce the risk associated with weather variability. However, especially for the state of Georgia, how much water is required and how much water is actually being used for irrigation is largely unknown. The objective of this study was to determine the relationship between farmers' irrigation applications, crop types, and local weather conditions. Farmers' monthly irrigation applications for three major crops in Georgia, i.e., cotton, peanut and maize, were obtained from selected sites of the Agricultural Water Pumping program. Significant relationships between monthly irrigation depth and monthly water deficit were obtained for only two of seven months for cotton, five of seven months for peanut, and only one of six months for maize. Individual differences among farmers on how much water they applied contributed to the lack of correlation between monthly irrigation depth and monthly water deficit. Future efforts should focus on a better understanding of the factors that contribute to the farmer's decisions related to when to irrigate and how much water to apply.