GREATPLAINSGRAZING.ORG – Healthy soils may help buffer agricultural systems in the Southern Great Plains (SGP) against increasingly variable and extreme precipitation events, higher temperatures, and more prolonged and intense droughts. Healthy, organic-matter-rich soils do not erode as readily as soils with less organic matter, and they hold more water and dry more slowly. In recognition of this, a growing number of producers across the SGP currently manage their farms with an emphasis on improving soil health by reducing disturbance and increasing soil organic matter.

While studies on soil health management practices (SHMPs) and soil health are relatively widespread, they generally focus on small groups of producers or a single location. However, soil types are widely variable across the region, and pronounced temperature and precipitation gradients further complicate application of these studies to larger scales. A better understanding of the effects of SHMPs at the region-wide scale is vital, especially due to the expected impacts of climate change on this region’s agricultural productivity and resilience, but no current studies explicitly compare SHMPs and traditional management across the region.

Dr. Caitlin Rottler, the Southern Plains Climate Hub Fellow at the USDA Grazinglands Research Laboratory in El Reno, OK, is working to determine the effect of SHMPs on un-irrigated cropland in Kansas, Oklahoma, and northern Texas. To do this, she will be collecting data on the physical, biological, and chemical properties of soils on both traditionally managed and soil-health-managed farms.

This spring, Rottler will sample at 12 locations in KS, OK, and northern TX, represented by green stars in the above image. Her study design makes use of paired fields at each location: one field managed with SHMPs and one managed with traditional management practices. She has chosen fields that are representative of the most common soil health and traditional management practices for the area. SHMPs generally incorporate no-till or reduced till, and, depending on the region, also incorporate monoculture or mixed cover crops and integrated livestock grazing, while traditional management practices generally incorporate more extensive tillage and may not include cover crops or integrated livestock grazing. Each location will include three pairs of fields, and soil analyses will include soil texture and bulk density (physical); percent C, N, and organic matter, pH, and electrical conductivity (chemical); and microbial community characteristics (biological). The objective of her research is to use this suite of soil health indicators to characterize if, and to what extent, SHMPs improve or conserve soil health across the Southern Plains, and to determine if these effects are consistent across the region.