Comparison of Five Tillage Systems in Coastal Plain Soils for Cotton Production

Abstract

Soil compaction management in the southeastern USA typically relies heavily on the practice of annual deep tillage. Strip tillage systems have shown considerable promise for reducing energy and labor requirements, equipment costs, soil erosion, and cotton plant damage from blowing sand. Replicated field trials were conducted for three years in South Carolina, to compare the performance of three different strip tillage systems to conventional tillage and no-till methods. A second objective was to investigate whether the frequency of deep tillage can be reduced by planting cotton directly using controlled wheel traffic into the previous year’s subsoiler furrow. Tillage treatments included: conventional tillage (disk-subsoil-bed), straight shank strip-till, bent-leg shank strip-till (Paratill), bent-leg shank strip till (Terra Max), and no-till. Deep tillage was performed in all plots the first year. In years two and three, the plots were split and half received annual deep tillage and the other half were not deep tilled either year. Tillage methods were compared side by side with and without irrigation. Deep tillage reduced soil compaction and increased taproot length and cotton yields than the no-till system. There was no difference in cotton lint yield between the strip-till systems and conventional tillage in either dry land or irrigated plots. Deep tillage increased cotton lint yields compared to no-till. There was no difference in lint yield between plots which were deep-tilled in all three years with those which had tillage operation only in first year of the test. Dry matter partitioning at first bloom was reduced in plant height, total dry weight, and leaf area in strip-till and no-till production systems compared to the conventional tillage system. The results suggest that all three strip tillage systems are equally effective for cotton production and that annual deep tillage is not necessary if controlled traffic is employed.