Developing Spatial Management Zones for Salt-Affected Soils in South Dakota Using Inherent Soil Properties and Yield History.

Eastern South Dakota (SD), USA agriculture is dominated by row crop production of primarily corn (Zea maiz), soybeans (Glycine max), and wheat (Tritium aestivum). In the past two decades, the salt-affected areas are increasing each year, though the total area is difficult to quantify. The soil salts limit and prevent crop yield of these salt-sensitive crops and cause producers to change management practices in order to maintain productivity on salt-affected soils. The objective of this study was to identify spatial predictors to locate salt-affected soils, and in doing so, create management zones for mitigation. Soil cores were collected from various points across two fields in Day and Spink Counties, SD and analyzed for pH, total soluble cations (TSS), electrical conductivity (EC), sodium adsorption ratio (SAR), and gypsum content. From each soil sampling point, soils were characterized by series, Mollic epipedon thickness, depth to redoximorphic features, and Natric horizon depth. These soil properties were then spatially evaluated using the ArcGIS 10.3 geostatistical analysis toolset using regression kriging. The spatial salt data was then combined with historical yield maps to generate management zones using Yield Editor 2.0. The results of this project will allow producers to identify the risk factors of salt-affected soils and prevent and manage these areas to improve crop growth.