Farmers in Nebraska are researching how cover crops work in the north central region and, particularly, how they affect a dryland cropping system.
Providence Farms, LLC is the joint farming venture of brothers Brian and Keith Berns of Bladen, NE. Brian and Keith, along with their families, farm more than 2,000 acres in south central NE. The farm is about 1/3 pivot irrigated and 2/3 dryland, and has been under continuous no-till production for 10-15 years.
The Bernses were interested in conducting a trial study to measure the water usage of various cover crops seeded into no-till dryland wheat stubble after harvest and measuring the impact of the cover crops on the yield of the following year's crop. In 2007, Keith Berns submitted a proposal to the North Central Region SARE (NCR-SARE) Farmer Rancher Grant Program and was awarded $5,990 for the on-farm research trial.
"The first question and major concern any dryland farmer has about cover crops is: 'How much water will a cover crop use?'" said Keith Berns. "This project attempted to answer that question regarding the use of cover crops in a dryland no-till cropping system."
The Bernses consulted with cover crop specialists to determine what species to use and what mixtures to consider. Factors that were considered in the selection of cover crops were: cost of seed, ease of seeding, variety, and life span. Based on that criteria, cover crops that were used included broadleaves, grasses, legumes, and mixtures.
The Bernses seeded a 20 foot strip of each selected cover crop into wheat stubble. They planted 50 acres of a cover crop mix on the same field to be used for grazing trials. They installed soil moisture sensors at three different subsoil levels and took photographs to monitor and catalog the growth and water use of their cover crops and cover crop mixes.
The late summer and early fall of 2008 was a wet period for Providence Farms, but they gleaned some useful data from the moisture use trial study. For instance, cover crop mixes showed less water use than did heavy use crops such as sunflowers and soybeans, and cover crop mix water use charts were similar to the water use chart for wheat stubble alone.
As for trial yields, Berns reported that corn planted into cover crop mixes yielded significantly better than corn planted into plain wheat stubble or a monoculture cover crop, and that corn planted into a monoculture cover crop mixes did not yield significantly less than corn planted into plain wheat stubble. Regarding the grazing trials, cover crop mixes provided high quality late fall and winter supplemental grazing for livestock, according to Berns.
Based on the trial results, Berns believes that cover crop mixes can be beneficial to yield of the next crop. They even developed an online cover crop seed selection tool that allows a farmer to choose from nearly 40 different species of legume, brassica, grass, and broadleaf crops.
"The results of this project have made us firm believers in cover crops," said Berns. "We will continue to experiment with different mixes, seeding rates, and plant species. We also hope to continue to monitor water usage of cover crops and also measure yield in the crop following."