Soil health within transitions from irrigation to limited irrigation and dryland management

Abstract

The decline in groundwater supply in the Texas High Plains is forcing some growers to convert center-pivot irrigated cropland to dryland production. Transitioning toward reduced water input can lead to declines in soil health. We assessed short-term changes in soil health indicators in two transition scenarios: (a) from high irrigation method to low irrigation method (center pivot to subsurface drip) and (b) from high irrigation method to dryland (center pivot to dryland), in comparison to continuous center-pivot management. We monitored changes in chemical and biological indicators in four fields for each transition scenario and in three pivot-irrigated fields. There were declines in soil water content, potassium (K), sodium (Na), and soil organic carbon with transition from irrigation to reduced irrigation and dryland. Severe drought in the final year revealed reduced amounts of multi-enzyme activities, total ester-linked fatty acid methyl ester (EL-FAME), and total fungi. Transitioning to low water-input management in this environment complicates efforts to maintain microbial components of soil health. Longer-term comparisons are needed to detect slow changes in soil health indicators on producers’ fields.