Evaluation of physical strategies for kochia ( <i>Bassia scoparia</i> ) patch management and soil remediation

Kochia is a problematic tumbleweed that infests Prairie annual cropping systems. Due to herbicide resistance adaptation by kochia, additional nonchemical management methods are required. The study objective was to evaluate the efficacy of physical management strategies on kochia stand densities and soil characteristics, including microbiome, chemistry, and allelochemical buildup within established kochia patches on the Prairie. Unmanaged infestations reached a maximum stand density of 10 000 plants m −2 in 2022. Black plastic mulch completely suppressed kochia while mowing reduced densities to 2%–7% of the untreated control in 2021 and 2023, respectively. The chaff treatment was effective over the 3-year term, with one application reducing stand densities to 5%–14% of the untreated control in 2021, 5%–22% in 2022, and 22%–56% in 2023. Mowing may be suitable where total crop failure may occur to prevent kochia reproduction. Field chaff was a promising option to limit stand densities but additional study is required for compatibility within annual cropping systems. Soil allelochemicals were rarely detected above thresholds, a promising result for soil remediation post-infestation. Neither the diversity nor the composition of the soil bacterial and fungal communities were impacted by mechanical treatments; however, kochia patches were associated with specific microorganisms compared to the cropped soil, including Thanatephorus and Neocamaosporium. The soil EC in the patch declined each year, and soil electrical conductivity, NO 3 -N, and SO 4 -S were the most important characteristics to explain kochia density using machine learning.