By Tara Maxwell
Cover crops are increasingly being used by farmers across the country to suppress weeds, conserve soil, protect water quality and control pests and diseases.
The fourth annual SARE/CTIC Cover Crop Survey collected data from more than 2,000 growers from 48 states and the District of Columbia. The survey provides insight into cover crop usage and benefits and explores what motivates farmers to include cover crops in their farm management and soil health plans.
Respondents reported a steady increase in the number of acres they have cover cropped over the past five years. They said the most important benefits of cover crops include improved soil health, reduced erosion and compaction, and increased soil organic matter. Other reported key benefits of using covers are weed and insect control, nitrogen fixation, attracting pollinators and providing deep taproots.
North Central SARE (Sustainable Agriculture Research and Education) and CTIC (Conservation Technology Information Center) sought data on how farmers use cover crops to manage their fertilizer inputs. Growers were asked to indicate their level of agreement with a series of fertilizer-related statements using a scale ranging from 1 (strongly agree) to 5 (strongly disagree). The statement that got the highest level of agreement was “Using cover crops has enabled me to reduce application of nitrogen on my cash crop,” with 134 of 1,012 respondents strongly agreeing and 244 checking “agree.” The statement that had the highest level of disagreement was “Using cover crops has required me to use additional crop fertility inputs over time to meet the needs of my cash crop.”
Cover Crops & Yields
For the fourth year in a row, the survey found yield increases in both corn and soybeans after cover crops (1.9 percent in corn and 2.8 percent in soybeans). According to the survey analysts,
“Those are modest bumps, but they are statistically significant. A new angle of exploration — on the effects of a cereal rye cover on a subsequent crop of soybeans — revealed that a majority (52 percent) responded that their soybeans often or always rise after a cover crop of cereal rye. Notably, 82 percent said cereal rye cover crops helped with weed control. In all, the popular practice of planting cereal rye cover crops before soybeans was validated in this year’s survey.”
While a majority of those surveyed saw no loss in profit, or lacked the data to tell, about one-third found a profit increase from cover crops, and two-thirds of the respondents said cover crops helped yields remain steady during extreme weather events.
Cover Crop Mixes & Timing
Cereal rye was the most popular cover species in the survey, followed by radish. However, cover crop mixes were planted on nearly as many acres as cereal rye. More than half of the participants in the survey reported that they started with a single species and “graduated” to mixes, while another 17 percent started with mixes and increased their use of blends. 61 percent of the respondents said they designed their own blends and 22 percent relied on their crop consultant or cover crop seed dealer to help them develop a mix.
Legumes are popular among many cover crop users because they fix nitrogen in the soil, in addition to all the other benefits of covers. Crimson clover led the legume category in average acreage per user, followed by winter pea, hairy vetch, other clovers, cowpea, red clover, other vetches and sun hemp.
Covers have traditionally been planted after harvesting cash crops. However, many farmers have found that seeding cover crops into growing cash crops can provide a vital head start in cover crop establishment.
Tara Maxwell served as managing editor of Acres U.S.A. magazine for 8 years. She is a graduate of Virginia Tech with a background in journalism and animal science, and has a passion for sustainable farming.