Spatial Response of Near-Surface Soil Water Contents to Newly Imposed Soil Management.

A landscape's hydrologic response to rainwaters is a function of the soil's antecedent soil water contents near the surface. The capacity of soil to infiltrate and store rainwaters vs. the capacity to induce overland flows and water-driven soil erosion is directly affected by the soil’s surface water content. Therefore, land management induced changes to the near-surface soil water contents should be a primary consideration for landscape hydrologic models and prediction networks. However, the within-field spatial variability of the soil water contents are rarely considered. Currently, the literature lacks nearly any evaluations of side-by-side, agronomic soil management effects on semivariogram spatial patterns of near-surface soil water contents. Among the few studies that are published in the scientific literature, these data evaluate landscapes that have a long, continuous history of a single management practice. To our knowledge, no study exists that has evaluate the spatial patterns of near-surface soil water contents of newly imposed soil management practices. Therefore, our objective was to measure soil water contents near the soil surface along transects of agricultural fields with newly imposed, side-by-side management practices (i.e., conservation tillage practices and use of cover crops) and report their spatial patterns and model parameters. Data will be presented from fields in North Dakota, Minnesota, and Iowa. These data, although brief and preliminary in scope, provide clear proof of concept that differences in spatial patterns can be clearly detected in newly imposed soil management systems even though differences in the experimental plot’s mean values are not always detected.