Five Years of Subsurface Drip Irrigation on Peanut: What Have We Learned?1

Abstract Long term peanut yield with various crop rotations and irrigated with subsurface drip irrigation (SDI) is not known. A subsurface drip irrigation system was installed in 1998 on a Tifton loamy sand (Fine-loamy, kaolinitic, thermic Plinthic Kandiudults) with five crop rotations, two drip tube lateral spacings, and three irrigation levels. Crop rotations ranged from continuous peanut (Arachis hypogaea L.) to four years between peanut rotated with either cotton (Gossypium hirusutum L.) and/or corn (Zea mays L.). Laterals were installed underneath each crop row (narrow) and alternate row middles (wide). Crops were irrigated daily at 100, 75 and 50% of estimated crop water use. Continuous peanut yields averaged 3107 kg ha−1 while peanut in rotation averaged 4031 kg ha−1. Yield of peanut in any rotation and with narrow spaced drip tube laterals averaged 4883 kg ha−1 and wide spaced laterals averaged 4592 kg ha−1. Peanut in any rotation and irrigated at 75% had the same pod yield as the 100% irrigated i...