Site-Specific Variable Rate Irrigation as a Means to Enhance Water Use Efficiency

Abstract

Abstract. The majority of irrigated cropland in the US is watered with sprinkler irrigation systems. These systems are inherently more efficient in distributing water than furrow or flood irrigation. Appropriate system design of sprinkler irrigation equipment, application methods, and farming practices (e.g. furrow diking) enhance crop water use efficiency by minimizing irrigation losses and improving soil water storage. For years, the paradigm for best irrigation management practices included uniform application over an entire field, even though abiotic (soils, slope, aspect, etc.) and biotic (insect pressure, plant disease) factors often cause spatial variations in water use and yield potential. However, emerging technologies such as wireless communication coupled with soil water and plant sensors, commercially available variable rate irrigation (VRI) equipment, and the development of algorithms for computational data processing are shifting this paradigm towards variable rate management as a means to enhance crop WUE. This paper focuses on the potential of site-specific variable rate irrigation management (SS-VRIM) as a tool for enhancing water use efficiency, and the challenges encountered.