Establishing Irrigation Thresholds for Furrow-Irrigated Peanuts

Abstract

© 2019 American Society of Agronomy and Crop Science Society of America 5585 Guilford Rd., Madison, WI 53711. Scheduling irrigations for furrow-irrigated peanut (Arachis hypogea L.) based on soil moisture potential could improve yield and net returns by ensuring adequate season-long soil water availability. This research was conducted to determine if sensor-based irrigation scheduling improves peanut yield, net returns above irrigation costs, and irrigation water use efficiency relative to FAO-56, a water balance irrigation-scheduling method that determines evapotranspiration using meteorological data and crop growth stage. The effects of irrigation scheduling (FAO-56, -50 cbar, -75 cbar, -100 cbar, and non-irrigated) on peanut yield, net returns above irrigation costs, and irrigation water use efficiency were investigated at Stoneville, MS on a Bosket very fine sandy loam (fine-loamy, mixed, active, thermic Mollic Hapludalfs). Relative to non-irrigated and FAO-56, maintaining the soil moisture at -50 cbar improved peanut yield at least 12.7% and either had no effect during wet years or improved net returns above irrigation costs up to 20.7% during dry years (P ≤ 0.0376). Maintaining soil moisture at -50 or -100 cbar either had no effect during wet years or increased irrigation water use efficiency by at least 5.3-fold relative to FAO-56 during dry years (P = 0.0071). Our data indicate that peanut yield, net returns above irrigation costs, and irrigation water use efficiency are more consistently optimized in furrow-irrigated environments by maintaining a season-long irrigation threshold of -50 cbar.