Soil Properties, Soybean Response, and Economic Return as Affected by Residue and Water Management Practices

Abstract

Soil, water, and air quality can be positively impacted by alternative crop residue management practices that return residue to the soil. Double-crop production systems, particularly those with a grass included in the rotation, rely on successful residue management practices. Soil quality and overall soil tilth are often low in regions with a long history of intensely cultivated, row-crop production, such as in the Mississippi River Delta region of the mid-South. Therefore, the objective of this study was to evaluate the effects of alternative residue (i.e., tillage, residue burning, and residue level) and water management practices on soil properties, soybean [ Glycine max (L.) Merr.] production, and net economic returns, over two consecutive rotations in a wheat (Triticum aestivum L.)–soybean double-crop system in the Mississippi River Delta region of eastern Arkansas. Initiated in 2001, this study reports results from years 4 and 5 of the experiment. Residue management effects were inconsistent among soil properties and years, and differences were generally agronomically non-significant. Averaged across irrigation treatments, soybean yield was unaffected by tillage, burning, and residue level either year. Within the non-irrigated treatment, conventionally tilled (CT) soybean yield was 38 % greater (p < .05) than no-tillage (NT) in 2005, but similar in 2006. In 2005 and 2006, irrigated soybean yield was 34 and 26 % greater (p < .05), respectively, in the burned than non-burned treatment. In 2006, the estimated net return from the high residue/burned/NT/irrigated treatment combination was 51 % greater than the traditional combination of high residue/burned/CT/irrigated soybean. By years four and five following conversion from CT to NT, the more environmentally sustainable practice of NT appears to be a viable, and potentially more profitable, alternative to the traditional and common practice of CT.