Wild crop relatives and landrace cover crops for arid-land vineyards

This project faced disruptions from Covid-19 and was terminated as "incomplete."

Commodities

• Agronomic: peas (field, cowpeas), wheat
• Fruits: grapes

Practices

• Crop Production: cover crops, intercropping, no-till

For our two-year project, ‘Wild-crop relatives and landrace cover crops for arid-land vineyards,’ our goal is to quantify the cost and efforts required to establish arid-adapted cover crops in a Willcox, AZ-area vineyard. The benefits of cover cropping have been well demonstrated in vineyards located in regions with higher rainfall, but water use and other associated costs can be a barrier to adopting cover cropping in arid regions. We will address the economic barriers to establishing cover crops in the desert by planting arid-adapted wild-crop relatives and landrace crops native to- or with a long history in the region, which will require less water and other inputs to thrive. Further economic support for cover cropping will come from the valuable seeds produced by our trial crops which farmers will be taught to save, and can be sold on contract to our partner Native Seeds/SEARCH, a regional seed bank. We will compare two cover cropping regimes with either wild tepary beans or cowpeas planted in the warm season, followed by Sonoran White wheat in the cool season. We will also quantify the cover crops' biomass and row cover to measure the impacts on weed suppression and water retention but also to ensure trial plants are growing robustly enough to provide other benefits from cover cropping like top soil retention and increased organic matter in the soil. Trials will take place in the Sand-Reckoner Vineyard (4798 E Robbs Road, Willcox, AZ 85643) in rows under production. Should the trial crops pass muster, we will disseminate good management practices for low-water use cover crops in Arizona vineyards, at field days, short workshops, the Arizona Wine Growers annual conference, instructional publications, and social media in conjunction with Native Seeds/SEARCH.

1. Evaluate 1 wild-crop relative and 2 heirloom crops for use as cover in a production vineyard for row coverage (weed-suppression), biomass (soil organic matter), cover crop seed yield (harvest value).
2. Quantify the costs – seed costs, establishment costs like water and mulch, harvest labor; and benefits – potential nutrient contribution, reduction in mowing frequency, seed harvest value of cover crop seeds.
3. Encourage the adoption of arid-adapted cover crops by disseminating best practices, including seed recommendations.
4. Preserve crop biodiversity by demonstrating the utility of heirloom crops and crop wild relatives in sustainable agricultural production.