Dairy farmers in California’s Central Valley are at the forefront of a movement bringing conservation tillage to the region.
Michael Crowell of Turlock is one of the pioneers.
“Today, I basically harvest my winter forage and then go right in and direct seed into the stubble with my corn planter,” he says. “I have eliminated all of the seedbed preparation.”
He harvested corn silage in mid- to late August last year – about two weeks later than normal. This past fall he ran a scraper across those fields to reduce the weeds, then spread dry manure and no-till-drilled a grain mix that included winter wheat, oats and rye.
Since going no-till, the producer has dramatically reduced the number of passes across his fields, resulting in significant savings in fuel, labor and equipment costs.
One of the most important benefits is improved soil health. Leaving plant roots largely undisturbed helps build carbon in the soil, says Crowell, who holds the 2011 Conservation Tillage Farmer Innovator Award from California’s Conservation Tillage and Cropping Systems Workgroup.
Under no-till, his corn silage yields have reached about 30 tons per acre – comparable to what he was getting under conventional tillage. His No. 1 rule for successful no-till farming is simple: “Stay off your ground when it’s wet.”
While conservation tillage is a well-established practice in other parts of the country, it’s relatively new to California.
A 2006 survey of the nine-county Central Valley region found that conservation tillage was used on just 3% of the acreage for selected crops, including corn silage and winter cereals grown for forage. Two years later, it had jumped to about 10%.
Jeff Mitchell has worked with several growers in the San Joaquin Valley to evaluate strip-till and no-till in dairy forage production. A crop specialist at the University of California, Davis, he’s seen good results with both methods.
“In the dairy corn sector, there’s probably more strip-till going on,” he says. “It’s an easier, more readily adaptable practice than going out and doing no-till. The bottom line is that we’ve seen success stories using both strip-till and no-till for corn silage and winter forage.”
Fields are strip-tilled in early spring just after the winter forage crop is chopped.
The idea is to loosen the soil when it’s still fairly dry, says Mitchell. Growers then pre-irrigate fields and plant silage corn. Borrowing a practice from the Midwest, California strip-till farmers have started to plant and fertilize in the same pass.
The average dairy producer can eliminate four to five tractor tillage passes by converting from conventional tillage to strip-till. That can cut costs by more than $50/acre, he says. Strip tillage may not work well in heavy soils, however.
Conservation tillage requires that growers, “recognize that they have to be really timely with respect to weed management and irrigation,” he says.
Of two Sustainable Agriculture Research and Education Program grants that helped fund Mitchell’s forage studies, the second looked at conservation tillage as a tool to enable year-round triple-cropping.
Triple-cropping has the potential to increase the total amount of annual plant nutrient uptake, allowing dairies to move more manure from corrals to fields. It’s an important consideration given California’s strict regulations on groundwater pollutants, including nitrates.
But triple-cropping will not fit every situation, Mitchell cautions.
Crowell tried it for three consecutive years, but plans to abandon the practice. Trying to sandwich a sorghum-sudan crop between corn silage harvest and winter forage planting was tricky in his northern San Joaquin Valley location.
“I’m not keen on triple-cropping right now,” he says. “The farther south you go, the better chance you have.”
Still, Crowell is a firm believer in no-till. To skeptics he says: “If you don’t think it’s going to work, it most likely won’t.”