Soil-water infiltration under crops, pasture, and established riparian buffer in Midwestern USA

The production-oriented agricultural system of Midwestern United States has caused environmental problems such as soil degradation and nonpoint source (NPS) pollution of water. Riparian buffers have been shown to reduce the impacts of NPS pollutants on stream water quality through the enhancement of riparian zone soil quality. The objective of this study was to compare soil-water infiltration in a Coland soil (fine-loamy, mixed, superactive, mesic Cumulic Endoaquoll) under multi-species riparian buffer vegetation with that of cultivated fields and a grazed pasture. Eight infiltration measurements were made, in each of six treatments. Bulk density, antecedent soil moisture, and particle size were also examined. The average 60-min cumulative infiltration was five times greater under the buffers than under the cultivated field and pasture. Cumulative infiltration in the multi-species riparian buffer was in the order of silver maple > grass filter > switchgrass. Cumulative infiltration did not differ significantly (P < 0.05) among corn and soybean crop fields and the pasture. Soil bulk densities under the multi-species buffer vegetation were significantly (P < 0.05) smaller than in the crop fields and the pasture. Other measured parameters did not show consistent trends. Thus, when using infiltration as an index, the established multi-species buffer vegetation seemed to improve soil quality after six years.