Peanut Response to Crop Rotation, Drip Tube Lateral Spacing, and Irrigation Rates with Deep Subsurface Drip Irrigation

ABSTRACT Long term crop yield with various crop rotations irrigated with subsurface drip irrigation (SSDI) is not known for US southeast. A SSDI system was installed in 1998 on Tifton loamy sand soil 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. Laterals were installed beneath each crop row (0.91-m) and alternate row middles (1.83-m). Crops were irrigated daily at 100, 75 and 50% of estimated crop water use. Laterals spaced at 1.83 m had the same yield as laterals spaced at 0.91-m in nine out of ten years. The 50, 75, and 100% irrigation treatments averaged 3263, 3468, and 3497 kg/ha, respectively. There was no yield difference between the 75 and 100% irrigation treatments implying 25% water savings. Crop rotation affected peanut yield seven out of eight years and continuous peanut had lowest yield across all years. As time between peanut crops increased peanut yield increased. Irrigation treatment had no effect on total sound mature kernels (TSMK). Lateral spacing affected TSMK 20% of the time and crop rotation affected TSMK 90% of the time. Continuous peanut rotation had the lowest TSMK with higher TSMK occurring as time between peanut crops increased. There was no evidence of any one crop rotation negatively affecting kernel size distribution except for continuous peanut. When using SSDI, it is possible to save 25% irrigation water, install drip laterals in alternate row middles, and rotate with peanut every three years without negatively affecting peanut yield or grade.