Submitted to: Soil Science Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 8/21/2019
Publication Date: 11/12/2019
Citation: Perez-Guzman, L., Phillips, L.A., Acosta Martinez, V. 2019. Next generation soil biological health indicators: Linking el-fame microbial markers with p-nitrophenol enzyme activities and functional gene qpcr. Soil Science Society of America Annual Meeting. Presentation. San Antonio, TX, November 10-13, 2019.
Technical Abstract: Methods to measure soil biological health are rapidly advancing. Currently, enzyme activity (EA) and ester-linked fatty acid methyl ester (EL-FAME) assays are accepted as Tier 2 indicators of biological activity and community structure by the Soil Health Institute. Alternate methods, such as quantitative PCR (qPCR) assays of functional and taxonomic communities, are newly emerging Tier 3 indicators. To facilitate comparisons of soil biological health between research groups that may employ different methods, we applied these current and emerging indicators to semiarid soils from the Texas High Plains (THP), which are sandy, alkaline, and have low organic matter (<1% OM). Soils were sampled in the growing season and post-harvest from 2014 through 2018, at five farms with irrigated or non-irrigated cotton cropping systems. Tier 2 EL-FAME and EA including ß-glucosidase, alkaline phosphatase, ß-glucosaminidase were measured and compared to qPCR assays of equivalent taxonomic and functional genes. These soils tested the sensitivity (low limit detection) of these methods. The different approaches for assessing either function or community were highly comparable (r > 0.79) and provided similar information on how soil biological communities were responding to both management and climate. Agriculture in this region experiences climate extremes and detecting even small but incremental changes in the health of these fragile (highly eroded) soils is critical to support productivity.