Sensitivity of dynamic soil properties to long-term agricultural management on claypan soils

Conservation management practices have the potential to improve soil health status and ensure that agricultural lands remain productive for future generations, especially in regions with degraded soils. To assess the soil health benefits of conservation management in the Central Claypan Area of Missouri, two long-term (30-yr) agronomic production systems and an ecological reference site were compared. Study systems included a corn ( Zea mays ) - soybean ( Glycine max ) - wheat ( Triticum aestivum ) rotation under no-till with cover-crops (ASP), a corn-soybean rotation with tillage and no cover-crops (BAU), and a remnant native prairie which served as an ecological reference site (TP). A suite of soil health indicators were measured from soil samples collected to a depth of 0-15 cm. Indicators included physical, chemical, and biological properties. Overall, soil health indicators were greatest at TP followed by ASP and BAU. Soil organic carbon and total nitrogen were not sensitive to differences in agricultural management practices, although the more dynamic soil health indicators, such as total protein, permanganate oxidizable carbon, alkali-absorbed soil respiration, and fresh soil respiration, were significantly greater under ASP relative to BAU management. This study demonstrated the utility of dynamic soil health indicators, especially in formerly degraded soils, even after 30 years of conservation management.