Subsurface and Alternate-Middle Micro Irrigation for the Southeastern Coastal Plain

Abstract

ABSTRACT Micro irrigation offers advantages in water and energy conservation, but cost of annual replacement of many components makes it unprofitable for most agronomic crops. Alternative tubing placements could improve profitability. An experiment was conducted for a three-year period (1985-87) to evaluate three micro-irrigation lateral placements and two irrigation application modes for corn in a coarse-textured southeastern Coastal Plain soil. Tubing placements were surface in-row (SIR), subsurface in-row (SSIR), and surface alternate middle (SAM). Irrigation application modes were continuous and pulsed. There were no differences in corn grain yield except during moderate-to-severe drought. Yields were significantly lower for the SAM treatments in 1986 and for the SAM-pulsed application mode treatment in 1987. Small differences in irrigation water were required among the three tubing-placement treatments. The SSIR treatment required the least amount of irrigation water each year. There was no evidence of emitter plugging on any treatment. The systems, still in use, will be evaluated for longevity; profitability can then be estimated. Based on these results, all of these placements of micro-irrigation tubing can produce acceptable corn yields in the southeastern Coastal Plain.