Soil health in a changing climate: addressing challenges to maintain soil health in a semiarid region transitioning to dryland

Authors: Acosta-Martinez, Veronica

Submitted to: World Wide Web New Crops Center Purdue University Bulletin
Publication Type: Abstract Only
Publication Acceptance Date: 2/10/2020
Publication Date: 3/19/2021
Citation: Acosta Martinez, V. 2020. Soil health in a changing climate: addressing challenges to maintain soil health in a semiarid region transitioning to dryland . World Wide Web New Crops Center Purdue University Bulletin. Presentation. Cancelled due to Covid-19.

Interpretive Summary: The Southern High Plains of the USA is a warm, semiarid region characterized by sandy soils that are inherently low in soil organic matter (<1%) and prone to wind erosion. The region is experiencing a transition from irrigated to dryland crop production due to reductions in water availability from the Ogallala aquifer. Additional challenges are imposed by more frequent cycles of extreme droughts and heat waves due to climate variability. A scientist from ARS in Lubbock Texas has created a soil health network with collaborators from different institutions and universities to evaluate the soil health as affected by alternative management for this region. For example, understanding how the soil microbial community is affected by climate variability and alternative management for the region will provide indications of changes in soil health, functioning, and productivity. Alternative agricultural systems for this region include the integration of cattle into the cropping system, the incorporation of dryland sorghum for forage and biofuels, and the Conservation Reserve Program as Texas leads the nation in this restoration effort by the USDA. The combined efforts are focused on the evaluation of soil health for the selection of agroecosystems with improved microbial community and their potential functions.

Technical Abstract: The Southern High Plains (SHP) region is important for cotton production in the nation. This region is characterized by a semiarid climate with sandy soils that are inherently low in soil organic matter (<1%) and prone to wind erosion. The region is also experiencing a transition from irrigated to dryland crop production due to reductions in water availability from the Ogallala aquifer. Additional challenges are imposed by more frequent cycles of extreme droughts and heat waves due to climate change. Over the past 20 years, Acosta-Martinez has provided a comprehensive evaluation of the soil microbial community in terms of size, composition and activity, as affected by the complex interactions of climate variability and alternative management. This includes changes in functions related to biogeochemical cycling, organic matter and water dynamics, and productivity as indicators of soil health. Numerous collaborations have evaluated the integration of forages for livestock production into the cotton production, incorporation of dryland sorghum for forage and biofuels, and the Conservation Reserve Program as Texas leads the nation in this restoration effort by the USDA. Results from the research contributes to the Ogallala Water Coordinated Agricultural (OWCAP) project, a multi-disciplinary effort across the Great Plains to address issues of water decline and long-term agricultural sustainability across the Ogallala aquifer. The research also contributes to USDA-ARS-GRACEnet (Greenhouse gas Reduction through Agricultural Carbon Enhancement network) to provide information of organisms - and processes they govern - for selecting sustainable agricultural practices across the nation. The methods developed and applied to research have become a part of a soil health measurement framework used by initiatives such as the Soil Health Institute and NRCS. For example, the phospholipid fatty acid analysis (PLFA) and ester-linked fatty acid methyl ester (EL-FAME) methods have been compared in their ability to determine profiles of microbial community composition in soil samples taken from 15 states. Additionally, a combined assay for four enzyme activities will provide the comparison of a soil biogeochemical index (CNPS cycling) across regions while saving resources, time, and budget, and reducing chemical wastes. In summary, the efforts presented are focused on the evaluation of soil health for the selection of agroecosystems with an improved microbial community, resilience and other essential functions.