Buckwheat Cover Crops on Wisconsin Vegetable Farms: Grower Perspective, Genetic Variation, and a Weed Supression Study Using Tartary Buckwheat

View the project final report

• 2011 annual report

Commodities

• Vegetables: cabbages

Practices

• Crop Production: conservation tillage
• Education and Training: focus group, on-farm/ranch research
• Pest Management: allelopathy, mulches - killed, smother crops, weed ecology
• Production Systems: agroecosystems, holistic management, organic agriculture
• Soil Management: green manures, organic matter

Common buckwheat (Fagopyrum esculentum) is a widely used summer cover crop on Wisconsin fresh market vegetable farms. Buckwheat cover crops are believed to provide environmental and farm production benefits including improving soil quality and fertility, weed suppression, beneficial insect habitat, and erosion prevention. Despite its utility, the relative importance to growers of different functions of buckwheat cover crops is not well understood. We use a web-based survey instrument and interviews to identify common grower practices and questions. Survey results are shared with all participants. Farmer input is used to design a series of on-farm and on-station studies on buckwheat cover crops, including a weed suppression study, variety trials using different genetic lines, a comparison of reduced-tillage killing methods, and a late-summer planted, overwintered residue study. The weed suppression experiment includes a novel comparison with a cultivated relative of common buckwheat, tartary buckwheat, which has been shown to contain possibly allelopathic substances. This project provides farmers with information about their peers' practices, and promotes discussion and better management for buckwheat and other cover crops. It also details genetic variation and novel management techniques for this unique green manure.

Through this study, we plan to:

1. Conduct a survey on buckwheat cover cropping and disseminate the results to participants, which will allow them to compare their own practices to those of other growers.
2. Compare cover-cropping qualities of common buckwheat to a related species, tartary buckwheat, which shows promise in cold hardiness and allelopathy.
3. Compare reduced-tillage management techniques for killing a buckwheat cover crop, and evaluate the ability of a buckwheat mulch layer to suppress mid-summer weeds.
4. Compare different USDA buckwheat accessions for traits of interest in cover cropping.
5. Characterize weed growth and emergence in an early summer buckwheat cover crop in order to better understand the mechanisms by which buckwheat suppresses weeds.

• Table of expected outcomes