Low-Till Forage Production Taking Hold in Central Valley
Strip-tillage is gaining momentum among dairy farmers in California’s Central Valley as a strategy with many benefits: It saves fuel, labor and equipment costs; reduces soil disturbance and dust; and opens the door to improved manure nitrogen management in the face of tighter regulations.
Leading the way is University of California, Davis Crop Specialist Jeff Mitchell, who has received two SARE grants to conduct research on Central Valley dairies evaluating strip-till and no-till planting systems for corn and winter forage production, and assessing conservation tillage’s ability to enable year-round triple cropping.
In addition, Mitchell coordinates the Conservation Tillage and Cropping Systems Workgroup, a 1,500-member group of California researchers, farmers, industry representatives and others interested in the practice, which is well-established in other parts of the country but relatively new to California.
By converting to strip-tillage, a typical dairy producer could eliminate four to five tractor passes. With high fuel costs, fewer passes across the field are better not only for the field but also for the dairy producer’s bottom line. It has also been shown that strip-tillage and no-tillage for forage production can reduce particulate matter emissions by 50-90 percent compared with traditional tillage.
“We estimate a reduction in costs of $50 an acre by using strip-tillage instead of traditional tillage,” Mitchell says. “However, it is important to understand that strip-tillage may not work in all soil types; heavier soils may be more difficult than coarser soils.”
Mitchell’s first SARE grant, received in 2006, evaluated strip-till silage corn production following wheat forage at Larry and Daniel Soares’ 600-cow dairy in Hanford. The trials evaluated conventional, no-till and strip-till in replicated strips, each 10 acres, in an 80-acre field. Results showed corn plant populations were higher in the strip-tilled fields, and weed populations and yields were roughly equal among the applications.
In his second SARE grant, ongoing since 2008, Mitchell is expanding on previous research by evaluating the potential benefits of conservation tillage-enabled triple cropping as a means for producing more silage, and thereby removing more manure nitrogen from dairy corrals. His work involves side-by-side comparisons of standard tillage double cropping versus conservation tillage triple cropping on dairies in Modesto and Turlock.
California dairies struggle with excess nitrate in groundwater, and new state regulations prohibit applications of nitrogen that exceed 140 percent of crop removal. “This standard will force many dairies, especially smaller ones, out of business if they cannot acquire additional land,” Mitchell says. Triple cropping, however, can become “a potentially reliable component of sustainable nutrient management plans.”
Mitchell offers these thoughts for producers considering strip-tillage:
- When strip-tilling, having some moisture in the soil precludes bringing up large clods.
- Timely weed management is needed – time herbicide applications close to planting (within a week).
- Using the same GPS system for both the strip-tilling and planting operations will keep the planter on the strip-tilled area.
Read Mitchell’s SARE grant reports to learn more about his conservation tillage research: FW06-308, Conservation Tillage Forage Production in California’s San Joaquin Valley; and SW08-060, Triple-Cropping Dairy Forage Production Systems through Conservation Tillage in California’s San Joaquin Valley.
Interested in sustainable soil management? For in-depth, practical information on implementing conservation tillage and other ecological management practices, check out SARE’s Building Soils for Better Crops, 3rd Edition. Visit the Learning Center to see SARE's library of educational resources, or visit the project reports database to learn more about SARE's grant-funded research.