Microbial responses under differing ecosystems to promote agricultural sustainability on the Texas southern high plains

Authors: PETERMANN, BILLI - Texas Tech University; LEWIS, KATIE - Texas Agrilife; Acosta-Martinez, Veronica; STEFFAN, JOSHUA - Dickinson State University; LAZA, HAYDEE - Texas Tech University; SLAUGHTER, LINDSEY - Texas Tech University

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/12/2021
Publication Date: 11/9/2021
Citation: Petermann, B., Lewis, K., Acosta Martinez, V., Steffan, J., Laza, H., Slaughter, L. 2021. Microbial responses under differing ecosystems to promote agricultural sustainability on the Texas southern high plains [abstract]. ASA-CSSA-SSSA Annual Meeting Abstracts.

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, yet declining water resources have prompted greater focus on conservation management practices such as cover crops, crop rotations, and no-tillage to improve soil health and water storage. Soil microbial biomass and community structure drive many of the processes 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. Our ongoing study investigated soil and rhizosphere microbial community structure and function at two sites in the Texas SHP (Halfway and Lamesa) under three long-term (> 7 years) established cotton production management strategies: 1) Continuous mono-crop with conventional tillage, 2) reduced tillage with small grain cover crop, and 3) reduced tillage with a cotton/winter wheat rotation. Bulk soil samples from two depth increments (0-10 cm and 10-20 cm) and from rhizosphere samples were analyzed using ester-linked fatty-acid methyl esters (EL-FAMES) to measure soil microbial biomass and community structure between treatments and depths via non-metric multidimensional scaling (NMS) ordinations. Changes in microbial C and N-cycling activities were assessed using high-throughput fluorometric assays of extracellular enzymes, including ß-1, 4, glucosidase (BG), ß-1, 4, N-acetylglucosaminidase (NAG), leucine amino peptidase (LAP), and acid phosphatase (PHOS). Our results revealed management-induced differences in biological and associated soil properties at the Lamesa site (sandy) while Halfway (loam) revealed differences between irrigation levels, suggesting that conservation management practices including reduced tillage and diversified planting may improve soil health depending on soil texture in semi-arid agricultural regions such as the Texas SHP.