Research Case Study
Demonstrating the Potential for Triticale and Annual Ryegrass as Both an Alternative Winter Crop and a Soil Organic-Matter-Building Practice
Project reports: https://projects.sare.org/sare_project/FS11-253/
Problem Statement
Winter cover crops offer farmers a number of benefits: they increase soil organic matter, thereby protecting the soil from erosion during winter months; they provide an alternative, high-quality crop that can be used as forage in dairy and beef operations; and they can increase the sustainability and profitability of farms by decreasing environmental degradation and lowering input costs. Researchers at the University of Georgia conducted a two-year study on a farm in Screven, Ga., to identify and develop the management practices needed to produce a winter annual cover crop. In doing so they wanted to address problems specific to the farms of southeast Georgia, where the soil is low in organic matter and nitrogen, and has a limited capacity of holding water. The farmer, Jonny Harris, raises cattle and grows cotton, corn, soybeans and peanuts.
Not all producers in southeast Georgia are aware of a winter cover crop’s ability to increase soil organic matter, organic nitrogen and water-holding capacity. For those farmers who are aware of the benefits, few fully perceive the economic advantages to be gained from cover crops. With the rise in the price of feedstuffs for forage-based livestock production systems and the recent technological innovations in forage conservation technology, cover crops have the potential to be used as a cash crop, with farmers storing and selling their cover crop to local livestock and dairy operations. This gives an additional economic incentive, beyond those that are motivated by environmental protection, for farmers to increase the production of cover crops.
For decades, Harris had been growing winter cover crops to build organic matter in his fields and provide forage for his cattle. He partnered with University of Georgia researchers on this SARE-funded project to begin quantifying the benefits to his operation. “I understood that it was good, but we needed documentation. I couldn’t go to my neighbor and say if you use this as a forage cover crop, you can get this much production and market it for this much,” Harris said.
Methods and Practices
Over three years, different winter cover crops (annual ryegrass, triticale, annual ryegrass and crimson clover, triticale and crimson clover) were planted on a 45-acre tract of land divided into seven plots. Changes in soil organic matter, organic nitrogen, bulk density and water-holding capacity across the different plots were monitored and compared to a control where no cover crop was planted. Differences in yield for the cotton cash crop were also noted, and results between years were identified.
Results
Following the first year’s growing season, two varieties of ryegrass used for the cover crop were eliminated from the study and replaced with newer varieties. The study found that cover crop use increased soil organic matter by 1 percent in one year. The plots that used cover crops produced a cotton crop that yielded 150 pounds more of lint than the control plot. The results of the study were presented at a meeting the following year with more than 80 producers from the region present. The researchers placed emphasis on the need for further on-farm testing to add to information available for producers