Cotton, Corn, and Peanut Yield Under Subsurface Drip Irrigation

Abstract

Long term yield response with various crop rotations of corn (M) ( Zea mays L.), cotton (C) ( Gossypium hirusutum L.) and peanut (P) ( Arachis hypogeae L) is unknown when irrigated with subsurface drip irrigation (SDI) in the humid southeast. A SDI 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 in south west Georgia. Crop rotations were continuous peanut (PP), alternate year rotations with corn and peanut (MP) and cotton and peanut (CP), three year rotation (CMP), and four year rotation (CMMP). 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 for each crop. There was no yield reduction in corn or peanut when irrigating at 75% of the estimated water use compared with the 100% irrigation level. The narrow spaced laterals had over 6 and 7% increase yield for peanut and corn, respectively, compared with the wider spaced laterals. Corn yield with MP and CMMP rotations had 8% higher yield compared with the CMP rotation. In cotton, longer rotations of CMP or CMMP had 18% higher lint yields when compared with alternate year CP rotation. Peanut pod yield increased over 12% with a CP rotation compared with MP rotation with highest peanut yields achieved with the CMP rotation (5579 kg ha –1 ). Crop yield response indicates that crop rotation is a valid management decision even when using SDI. Economic simulations would need to be performed for individual growers to identify best economical irrigation level, lateral spacing, and crop rotation when irrigating with a SDI system.