Anaerobic soil disinfestation to break down herbicide residues in sweet corn-vegetable rotation systems

Overview

This solution addresses a critical agronomic challenge faced by sweet corn growers in the Southeast United States: the persistence of tembotrione and atrazine herbicide residues in soil, which can cause severe damage to vegetable crops planted in the following season. By leveraging anaerobic soil disinfestation (ASD), a process in which soil is amended with a carbon source, irrigated, and tarped with plastic mulch, this approach aims to harness the proliferation of anaerobic bacteria and organic compounds to accelerate herbicide degradation. The result is a practical, eco-friendly method that shortens rotation intervals and protects subsequent vegetable crops.

Technical specifications

Process and methodology:

• Soil amendment with readily available, farm-based carbon sources including molasses, mustard meal, and chicken manure, each selected for allelopathic properties
• Irrigation and tarping with plastic mulch to create anaerobic conditions in the soil
• Promotion of bacterial taxa affiliated with known anaerobes and fermenters, such as Acidobacteria and Bacteroidetes
• Generation of organic compounds including acetic acid and butyrate that contribute to herbicide breakdown

Experimental validation:

• Greenhouse pot experiments using a randomized complete block design with 10 replicates and a 4-week duration
• Factorial treatment structure with four amendments (molasses, mustard meal, chicken manure, and no amendment) crossed with two ASD treatments (ASD or no ASD)
• Post-treatment transplanting of vegetable plants with visual plant injury ratings and soil chemical analysis to assess herbicide persistence
• Field trials to evaluate the best-performing greenhouse treatments in actual sweet corn-vegetable rotation systems

Technology readiness level

This research is at an early-to-mid stage of development. The Clemson University weed science laboratory has already demonstrated through greenhouse and field studies that ASD treatments contribute significantly to weed control and pathogen suppression in soil. The proposed project will build on this foundation by specifically validating the ability of ASD to reduce tembotrione and atrazine concentrations in Southeast United States soils. Successful completion of greenhouse and field validation studies will be needed before this approach can be recommended for widespread commercial adoption by growers.