The survey tallies silage and grain corn; small grains for hay, silage and grain; tomatoes, cotton, dry beans, and melons managed as no-till, strip-till, ridge-till and mulch-till – which leave at least 30 percent of residue from the previous crops on the soil surface – in the nine-county Central Valley region. In 2010, such conservation tillage accounted for about 14 percent of the crops’ total acreage, an increase from about 10 percent in 2008. The survey also found that minimum tillage practices – which reduce the overall number of tillage passes by at least 40 percent relative to what was done in 2000 – were used on about 33 percent of crop acreage in 2010, up from about 21 percent in 2008.
There are many potential benefits for using conservation tillage, said UC Cooperative Extension cropping systems specialist Jeff Mitchell. Conservation tillage is credited with water conservation, dust suppression, reduced pesticide runoff into surface water, lowered labor needs and costs, and fuel savings. In addition, limiting tillage helps to keep carbon in the ground and prevent the buildup of greenhouse gases in the atmosphere.
CASI has conducted comparisons of annual row crop acreage farmed under different tillage systems in the Central Valley region since 2004. More than 35 Natural Resources Conservation Service, University of California and private sector experts take part in the survey.
The largest change in conservation tillage acreage from 2004 to 2010 is found in the amount of corn silage acreage that uses strip-tillage. In 2004, there were only about 490 acres of summer silage corn using strip-till, while in 2010 more than 103,000 acres in the San Joaquin Valley dairy region had adopted this form of conservation tillage. The overall use of minimum tillage practices has also greatly increased during this time from about 64,000 acres under reduced pass tillage in 2004 and just over 700,000 acres under minimum tillage in 2010.
California’s Conservation Agriculture Systems Institute involves more than 1,500 farmers, industry representatives, university, Natural Resource Conservation Service and other public agency members. Over the past 10 years, the team has come together to develop information on the costs and benefits of the production system and irrigation management alternatives and to develop long-term sustainability goals. For more information on the body of CT research, see the UC Conservation Tillage website.