Soil microbial biomass influenced by cover crop after fumigation of potato fields

Authors: TORABIAN, SHAHRAM - Oregon State University; KIM, ESTHER - Oregon State University; QIN, RUIJUN - Oregon State University; SATHUVALLI, VIDYASAGAR - Oregon State University; Gollany, Hero; KLEBER, MARKUS - Oregon State University

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2024
Publication Date: 12/9/2024
Citation: Torabian, S., Kim, E., Qin, R., Sathuvalli, V., Gollany, H.T., Kleber, M. 2024. Soil microbial biomass influenced by cover crop after fumigation of potato fields. Science of the Total Environment. 958.Article 177910. https://doi.org/10.1016/j.scitotenv.2024.177910.
DOI: https://doi.org/10.1016/j.scitotenv.2024.177910

Interpretive Summary: Soil fumigation is commonly used for pest control in potato production, although it can unintentionally harm non-target organisms in the soil. The presence of cover crops can significantly influence the abundance and composition of microorganisms. However, there is limited knowledge regarding the combined impact of soil fumigation and cover crops on soil health in potato fields. To address this knowledge gap, a field study was conducted at the Hermiston Agricultural Research and Extension Center, Oregon State University with a randomized split-plot design consisting of four fumigation treatments (no fumigation control, Telone, metam sodium, and co-applied Telone and metam sodium) as the main plots and five cover crop treatments (no cover crop, wheat, mustard, radish, and a mixture of winter pea and faba bean) as the subplots. Compared to the control, microbial biomass carbon (MBC) in non-fumigated soils of pea+fava bean, wheat, and radish increased by 41%, 37%, and 31%, respectively. In soils treated with metam sodium, the inclusion of cover crops led to increases of MBC values by 30%, 34%, 41%, and 40% in pea+fava bean, wheat, radish, and mustard treatments, respectively, compared to the control. The results demonstrated the potential of cover crops to enhance MBC.

Technical Abstract: Soil fumigation is commonly employed for pest control in potato production, although it can unintentionally harm non-target organisms in the soil. The presence of cover crops can significantly influence the abundance and composition of microorganisms. However, there is limited knowledge regarding the combined impact of soil fumigation and cover crops on soil health in potato fields. To address this knowledge gap, a field study was conducted at the Hermiston Agricultural Research and Extension Center, Oregon State University with a randomized split-plot design consisting of four fumigation treatments (no fumigation control, Telone, metam sodium, and co-applied Telone and metam sodium) as the main plots and five cover crop treatments [no cover crop, wheat (Triticum aestivum), mustard (Brassica nigra), radish (Raphanus sativus), and a mixture of winter pea (Pisum sativum) and faba bean (Vicia faba)] as the subplots. Compared to the control, microbial biomass carbon (MBC) in non-fumigated soils of pea+faba bean, wheat, and radish increased by 41 %, 37 %, and 31 %, respectively. In soils treated with metam sodium, pea+faba bean, wheat, radish, and mustard increased MBC by 30 %, 34 %, 41 %, and 40 % compared to the control. The results demonstrated the potential of cover crops to enhance MBC.