Addressing the Weed and Soil Management Trade-offs in Vegetables Through Integrated Cultural and Mechanical Strategies

View the project final report

Commodities

• Vegetables: carrots, cucurbits

Practices

• Pest Management: cultural control, physical control
• Production Systems: organic agriculture

Title:  Addressing Weed and Soil Management Trade-offs in Vegetables Through Integrated Cultural and Mechanical Strategies

Project Outcomes: We expect that our results will benefit farmers by helping them integrate cultural and mechanical weed management strategies to reduce the economic and environmental costs of weed management. We also expect that a better understanding of the interaction between cultivation tools and soil conditions will help farmers optimize their soil and weed management choices for their specific conditions to successfully manage weeds without excessive tillage.

Context:  Weed management is a major challenge for vegetable growers. Over-reliance on herbicides and tillage to manage weeds has contributed to both environmental and economic challenges including herbicide pollution, soil degradation and development of herbicide resistance. By integrating cultural and advanced mechanical weed management strategies, we hypothesize that Midwest vegetable growers can more effectively control weeds while minimizing environmental costs.  We also hypothesize that better understanding of the interactions between soil management and mechanical cultivation tools will help growers find an optimal balance between weed and soil management objectives. Farmers typically assume that flatter, more smooth beds are optimal for cultivation, but recent research has shown that some common forms of bed preparation may be unnecessary or even decrease cultivation efficacy through unfavorable effects on soil moisture or crusting (Priddy 2021).  Thus, we hope to understand how much bed preparation and pre-plant tillage is necessary so that farmers can minimize soil disturbance while still effectively managing weeds.

Approach:  In this project, we will take advantage of a long-term cropping systems experiment to evaluate interactions between soil management practices (tillage, compost and bed-preparation) and in-row mechanical cultivation efficacy in acorn squash.  We will also conduct field studies to evaluate strategies for integrating cultural and mechanical weed control in carrots, including the effects of cultivar choice and seed-priming on the efficacy of mechanical cultivation. We will use a novel 3D Lidar imaging approach to visualize and analyze soil conditions and their interaction with tools. Our findings will be shared with growers through an extension publication, conference presentations, and on an online forum for mechanical cultivation in vegetables.

Learning Outcomes:

1. Vegetable farmers will have a greater understanding of the value of cultural weed management strategies including cultivar choice and seed priming.
2. Vegetable farmers will be more aware of optimal pre-plant soil management practices for improved mechanical cultivation efficacy and selectivity.
3. Vegetable farmers will learn how to optimize mechanical tool choice under different soil conditions.

Action Outcomes:

1. Vegetable farmers will integrate cultural practices into their weed management plan to reduce reliance on herbicides and limit soil degradation on their farms.
2. Vegetable farmers will utilize optimal bed preparation practices and pre-planting decisions that improve cultivation efficacy without compromising soil health.
3. Farmers will optimize mechanical tool choice under different soil conditions. This will allow them to more effectively use long-term management strategies that are beneficial to soil health, since they will know how to effectively choose mechanical tools to manage weeds in these varied conditions.