Yagi Sisters Farm Field Trial

Results Summary

Many growers in the North Bay Area demonstrate a clear, long-term commitment to using soil health building practices such as compost, cover crops, and no-till. However, during a Needs Assessment in 2023, many growers expressed that is often economically and physically challenging to use strict no-till soil management practices on their farms all of the time. Farmers often think through the economic and ecological costs and benefits of using tillage at strategic times or in specific locations to help achieve farm goals. They often are faced with difficult decisions and need to balance farmer and farmworker health, labor, economics, and plant and soil health benefits to find an approach that is most appropriate for their unique farm situation.

This case study explores one example that illustrates how a small-scale vegetable grower thought through these tradeoffs that many growers grapple with. Findings offer an opportunity to foster and support open conversations about tillage and low/no-till approaches, farmer decision making processes, and small farm sustainability that integrates soil health and farmer health.

At Yagi Sisters Farm, farmer Reyna Yagi decided to use a walk-behind tractor in 2024 in strategic areas to reduce labor time and physical strain associated with hand-scale no-till practices. With support from the UCCE North Bay Specialty Crops Program, California Farm Demonstration Network and the North Coast Soil Hub, soil health data was collected and labor time and all associated costs were documented. Findings presented here shed light on the early impacts of one BCS tillage pass on soil health metrics and associated costs and benefits. This can help answer growers’ questions about the potential negative impacts of tillage on soil health (for example, “how bad is one strategic BCS pass on soil health? How much time could it save me?”). This work highlights concerns shared by many growers about the need to balance farmer physical health and soil health. Scale-appropriate equipment can serve as an injury and burnout prevention strategy and improve labor efficiency.

Prior soil testing showed high pre-existing soil health at this site before the trial due to its history of careful soil health management.

After implementing the trial, our data suggests only slight reductions in several soil health metrics occurred due to one tillage pass. Compared to no-till soil, the soil where the BCS was used had slightly lower average water stable aggregates, organic matter, CEC, moisture, active carbon, and nutrient levels, though these differences were often quite small. The BCS significantly reduced compaction when measured by resistance via penetrometer, but not when measured by bulk density. Average bulk density, water infiltration rate, respiration, soil texture, pH, and EC were similar between treatments.

Compared to strict hand-scale no-till practices, the BCS saved approximately 1.5 hours of labor per bed, reduced self-reported farmer physical pain and injury by half, and increased on-farm efficiency. However, there was a learning curve associated with using this equipment and mechanic labor shortages and limited parts posed hurdles to implementation. 

While this work provides an early look at immediate effects, more data would be required to evaluate how metrics might change over time with regular BCS passes. Multiple tillage passes over time would likely lead to meaningful declines in soil organic matter, nitrogen, water stable aggregates and potentially other soil health metrics, but the rate at which these changes could occur on small-scale diversified vegetable farms in our region is currently unknown.

Benefits: “The upside to the BCS is the reduction in physical labor compared to no till. While I felt fatigued after about 3 hours of using the BCS (they are a different type of physicality and I might add not usually suited to a woman of my size), I completed far more farm work in those 3 hours comparatively. I could complete a field section easily in the span of a day to prep for a big planting rather than prep beds either in a sporadic manner or spanning over a few days depending on managing other farm and job needs. It was incredibly refreshing to see 5-6 beds mounded (often a heavy task by hand) and beds that took minutes to incorporate compost. After a full season of integrating the BCS, I am not experiencing as much shoulder and neck strain and the numbing, pinched nerve issues that would wake me up at night constantly. There still is some pain, but it’s reduced by half in my opinion.”

Tradeoffs: “The downsides to the BCS are my lacking mechanic skills that creates a bigger learning curve and more time at the onset, the fact that I only have one so when a repair came up it took 5 months to repair due to mechanic labor shortages and limited parts availability of the BCS brand so I had to scramble to borrow one on a budget. I’ve also learned that the BCS brand may not be the best fit given that latter downside as that has a big factor in the economics of integrating this machinery into my farm.”  – Reyna Yagi, farmer