Assessing Cover Crop Effects on Soil Health Parameters.

Improving soil physical, chemical, and biological properties is essential to maintain or enhance the overall health of the soil and delivery of soil ecosystem services. Management practices can directly alter the health of the soils and their ability to provide services. Cover crops are an remerging strategy to improve soil quality or health, but research examining sensitive indicators of soil health on a comprehensive basis such as soil physical, chemical, and biological properties is limited. The purpose of this study is to determine the effects of cover crops on soil health indicators in a no-till corn (Zea mays L. –soybean (Glycine max L.)-winter wheat (Triticum aestivum L.) rotation in eastern Nebraska after 11 years of management. The experiment is a randomized complete block design with three treatments with different C:N ratios in triplicate. The treatments include: control (corn-soybean-wheat without cover crop) with C:N ratio of 2:1, cover crops with C:N ratio of 4:1, and cover crops with C:N ratio of 2:3.  We used cereal rye and grain sorghum cover crops with corn-soybean-wheat for the 2:3 ratio, and Austrian winter pea and soybean cover crops with corn-soybean-wheat for the 2:3 ratio. Each phase of the rotation was present each year, but, in this study, we only evaluated the corn rotation phase. We will measure bulk density, penetration resistance, dry and wet soil aggregate stability, soil organic C and  N, water infiltration, water retention characteristics, microbial community structure, soil water content, soil temperature, macro and micronutrients, and others for the 0 to 10 cm and 10 to 20 cm soil depths. These indicators will be integrated using a soil quality or health index for an overall assessment and better understanding of cover crop effects on soil health.