Tracking Vegetable Yields and Labor in a No-Till Perennial Clover Living Mulch System

View the project final report

Commodities

Practices

• Crop Production: cropping systems, no-till
• Education and Training: farmer to farmer, on-farm/ranch research
• Natural Resources/Environment: carbon sequestration
• Pest Management: mulches - living
• Production Systems: organic agriculture
• Soil Management: soil quality/health

Over 40 years of university research on perennial clover living mulches has documented its benefits - reduced tillage and erosion, improved aggregation and infiltration, N fixation, weed suppression, disease reduction - and consistent yield drag. For this reason, farmer adoption has been close to zero.

At Sawyer Farm, we've spent a decade experimenting with tillage reduction techniques and no-till systems (crimped rye, tarping, and transferred mulch), with mostly unsatisfying results. In 2020, we began transplanting vegetables in a perennial clover system (PCS). Initially a Hail Mary pass, PCS benefits were immediately clear (including reduced tractor and hand-weeding hours), and we found that timely mowings and large transplant sizes can largely offset yield reduction. As a commercial farm, we have not had the resources to gather data on yield losses relative to tilled controls, or to explore mowing and transplant size as they relate to labor and yields and university studies have largely ignored these variables. Farmers in our local and broader networks have expressed interest in PCS, but say they need more data on yield and labor to justify trials. 

The SARE partnership grant offers a rare opportunity for Sawyer Farm to collaborate with a UMass researcher with a strong background in PCS and another farmer hesitant to adopt PCS, to run rigorous trials aimed at answering the questions farmers want to know. The American Farmland Trust is another key collaborator; in addition to in-kind services, they will help Sawyer Farm with dissemination of results to Northeast farmers. 

The project seeks to identify key factors that affect soil health, vegetable yields, and labor in a perennial clover living mulch system (PCS).  

1. For each crop (cabbage, winter squash, and paste tomatoes), we will identify the smallest plug size growers can use without experiencing yield drag. 
2. For each crop, we will identify whether mowing clover according to variable high frequency versus variable low frequency affects yields, and track labor across both mowing regimens. Our data will provide information to guide growers in determining the appropriate mowing system for their operation.
3. Each crop will have an organic, tilled control that will allow us to measure labor and yield differences between PCS and the control. This data will empower farmers to make informed economic decisions about PCS. 
4. Comprehensive soil health assessment (Cornell CASH) will be compared (which includes SOC, SOM, soil respiration, active carbon, soil protein index, and other physical, chemical and biological indicators of soil health and fertility). Baseline tests will be collected in October of 2022, and tests will be taken in each treatment (PCS and tilled control) at the end of the 2023 season to provide initial information regarding carbon capture and nutrient retention in PCS versus control plots.