Soil microbial response to long-term management practices in cotton systems of the semi-arid Texas southern high plains

Authors: PETERMANN, BILLI - Texas Tech University; LEWIS, KATIE - Texas Agrilife; Acosta-Martinez, Veronica; LAZA, HAYDEE - Texas Tech University; STEFFAN, JOSHUA - North Dakota Parks And Recreation; SLAUGHTER, LINDSEY - Texas Tech University

Submitted to: World Congress of Soil Science
Publication Type: Abstract Only
Publication Acceptance Date: 11/19/2021
Publication Date: 8/2/2022
Citation: Petermann, B., Lewis, K., Acosta Martinez, V., Laza, H., Steffan, J., Slaughter, L. 2022. Soil microbial response to long-term management practices in cotton systems of the semi-arid Texas southern high plains. World Congress of Soil Science.

Interpretive Summary:

Technical Abstract: Agricultural producers in semi-arid regions such as the Texas Southern High Plains (SHP) face many challenges while attempting to increase soil health and profitability, particularly severe water and nutrient scarcity. Cotton production in the Texas SHP has historically relied on continuous cropping, tillage, and irrigation to sustain productivity, but declining groundwater resources have prompted greater focus on conservation practices such as cover crops, crop rotations, and conservation tillage to improve soil health and water storage. Soil microbial community size and composition drive many functions that influence plant productivity, such as nutrient cycling, improved soil structure and subsequent water dynamics, making them important indicators that can be used to assess soil health improvements. Soil samples were taken from two depths (0-10 cm, 10-20 cm) and from the root zone for two-years at a fine sandy loam site in this region under three long-term (> 7 years) cotton management strategies, each under high and low irrigation: 1) Continuous monocrop with conventional tillage, 2) reduced tillage with rye cover crop, and 3) reduced tillage with a cotton/wheat rotation. The microbial community among these systems were compared in terms of size (via ester linked-fatty acid methyl esters analysis), diversity (via amplicon sequencing) and C and N-cycling activities (via high-throughput fluorometric assays of extracellular enzymes). Our results revealed management-induced differences on soil microbial communities regardless of irrigation level, suggesting that conservation practices such as reduced tillage and diversified planting can improve soil health in course textured soils in this semi-arid region.