Location: Wind Erosion and Water Conservation Research
Title: Impacts of legume inclusion on soil microbial communities and greenhouse gas emissions in semi-arid pasture ecosystemsAuthor
SLAUGHTER, LINDSEY - Texas Tech University | |
RAAVI, ARORA - Texas Tech University | |
WEST, CHARLES - Texas Tech University | |
SANJIT K, DEB - Texas Tech University | |
Acosta-Martinez, Veronica |
Submitted to: World Congress of Soil Science
Publication Type: Abstract Only Publication Acceptance Date: 11/19/2021 Publication Date: 8/2/2022 Citation: Slaughter, L., Raavi, A., West, C.P., Sanjit K, D., Acosta Martinez, V. 2022. Impacts of legume inclusion on soil microbial communities and greenhouse gas emissions in semi-arid pasture ecosystems. World Congress of Soil Science. Interpretive Summary: Technical Abstract: Researchers are challenged with developing agroecosystems that conserve limited resources while improving production in the face of land degradation and climate change. This is critical in semi-arid systems already vulnerable to soil erosion, nutrient depletion, and extreme water scarcity. One economically feasible option is converting high-input row crop systems to grazed perennial grasslands, which conserve water and nutrient resources and provide the four soil health management principles (minimizing disturbance, increasing biodiversity, maximizing continuous living roots, and providing soil cover). Enteric methane (CH4) production from grazing cattle is a potential sustainability tradeoff in these systems, but it is likely possible to mitigate climate impacts through integrated soil-plant-animal management. The objective of this three-year study was to quantify how legumes (alfalfa, Medicago sativa L.) influence soil greenhouse gas (GHG) flux in established long-term pastures with either a N-fertilized warm-season perennial grass (WW-B.Dahl Old World bluestem, Bothriochloa bladhii (Retz) S.T. Blake) monoculture or unfertilized grass-legume mixtures. Soil GHG samples (CO2, CH4, N2O) were collected using static chamber methods in the field on a bi-weekly basis during the forage growing season from late spring to early fall, and on a monthly basis during the fall to spring. Soil samples (0-5 cm) were analyzed for microbial community size and structure using ester-linked fatty acid methyl ester (EL-FAME) analysis. The results of our study show how plant-soil interactions resulting from forage management regulate soil GHG emissions, and will ultimately help us create more efficient and resilient semi-arid agricultural systems across the globe. |