A Minimum Dataset for Soil Health Assessment in Missouri Claypan Soils.

Soils in the Central Claypan Region of Missouri present unique environmental challenges, including high runoff and erosion potential, rapid soil degradation, and reduced productivity. Soil health assessment is an important tool for evaluating the effects of land management practices on the biological, physical, and chemical functioning of soils in this region. Several candidate soil health indicators have been evaluated in long-term agroecosystems representing varied management practices, including annual grain cropping systems and working grasslands. In addition, the Soil Management Assessment Framework (SMAF) has been applied to evaluate soil function relative to its inherent potential based on site-specific characteristics. In these studies, candidate indicators that demonstrated sensitivity to management included total organic carbon, active carbon, soil enzymes, mineralizable nitrogen, bulk density, and phospholipid fatty acids. Biological and physical SMAF soil health scores were the most sensitive to management changes, while SMAF scores for soil chemical indicators were less sensitive, primarily due to the distribution of the data and the SMAF scoring algorithms. Future work includes development of a regional active carbon algorithm, modification of the aggregate stability and mineralizable nitrogen algorithms, and evaluation of soil respiration and soil protein as soil health indicators in the Central Claypan Region.