Long-term perennial management and cropping effects on soil microbial biomass for claypan watersheds.

Authors: ALAGELE, SALAH - University Of Missouri; ANDERSON, STEVE - University Of Missouri; UDAWATTA, RANJITH - University Of Missouri; Veum, Kristen

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 11/4/2020
Publication Date: 11/9/2020
Citation: Alagele, S.M., Anderson, S.H., Udawatta, R.P., Veum, K.S. 2020. Long-term perennial management and cropping effects on soil microbial biomass for claypan watersheds [abstract]. Proceedings ASA-CSSA-SSSA International Annual Meeting, November 9-30, 2020, virtual. Available: https://scisoc.confex.com/scisoc/2020am/meetingapp.cgi/Paper/124530

Interpretive Summary:

Technical Abstract: Sustainable vegetative management systems with their deep and extensive root systems can provide higher levels of residues and labile carbon necessary to increase soil carbon and promote soil microbial biomass and hence improve soil quality. The objective of this study was to evaluate the effects of grass buffer (GB), biomass crop (BC), grass waterway (GWW), and agroforestry buffer (AB) on soil microbial biomass and soil organic carbon (SOC) as compared to a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] rotation (row crop [RC]) on claypan soils. The RC, AB, GB, GWW, and BC treatments were established in 1991, 1997, 1997, 1997, and 2012, respectively. The study site was located at Greenley Memorial Research Center in Missouri, USA. Soil samples were collected in May 2018 from the 0- to 10-cm depth at summit, backslope, and footslope landscape positions. Within the AB treatment, soils were sampled from the 50-cm and 150-cm tree distances. Total microbial biomass and biomass of gram-positive bacteria, gram-negative bacteria, actinomycetes, rhizobia, fungi, arbuscular mycorrhizae, saprophytes, and protozoa were determined by phospholipid fatty acid (PLFA) analysis. Results showed that soil microbial biomass and SOC across all soil microbial communities were significantly higher (p < 0.01) under perennial vegetation treatments compared with RC management. The footslope position showed the highest total microbial biomass and SOC compared with the summit and backslope landscape positions. The distance of 50 cm from the tree base showed 16% higher total microbial biomass and 15% greater SOC than the distance of 150 cm. Overall, these findings highlight the impact of perennial vegetation, landscape position, and tree distance on soil biological properties and highlight the potential to increase soil microbial biomass and SOC in degraded RC management. Thus, perennial management systems can play a significant role in enhancing soil health for future sustainable production.