In a Louisiana field just north of the Rapides-Avoyelles parish line, a 45-acre plot that once grew sugarcane is now covered in Austrian winter peas, vetch and tillage radishes. These three cover crops are part of a study being conducted by LSU AgCenter researchers with cooperation from area farmers.
While cover crops are not new, there is renewed interest in the potential benefits these crops can provide, said AgCenter area agent Donna Morgan.
“I think producers are starting to see some of the benefits with the nutrients and improved soil health these cover crops can provide,” Morgan said.
Morgan is working with Will Bain, a sugarcane, soybean and rice farmer who farms in both Rapides and Avoyelles parishes. This is the second year for Bain to experiment with cover crops.
“I am interested in cover crops for two reasons,” Bain said. “The first reason is to add organic matter to the soil and improve soil fertility. Another reason is to reduce soil erosion.”
Cover crops are not grown to be harvested, but Morgan said farmers still must employ management strategies commonly found in crops grown for income.
“It is a crop you have to manage,” she said. “And manage in that you have to know which variety to plant, when to plant and when it needs to be terminated to get the most benefit.”
Most cover crops are terminated with a chemical spray, usually four to six weeks prior to planting the cash crop, which is now for those planning to plant corn, soybeans or cotton. Morgan recommends planting a cover crop as soon as possible after harvest in order to get the most benefit.
“If you wait too long, by the time the cover crop germinates and gets established, it may be out there only for two or three months before you have to terminate it,” Morgan said.
Bain’s situation is somewhat different. He does not plan to plant sugarcane where his cover crops are until August. This extended time will allow his cover crop to mature longer, and he hopes this will help increase the organic matter in his soil. He plans on spraying it in May and begin working his land in June to get ready for sugarcane planting.
“I went with a more legume-based approach [winter peas and vetch] mainly because I have a sugarcane rotation,” Bain said. “I have a problem in some fields with ryegrass in sugarcane, so I wanted to stay away from grasses.”
Variety types, planting dates
AgCenter researchers are studying issues such as variety types and planting dates on crops such as cereal rye, vetch and tillage radishes and how to properly terminate them.
“You don’t want that cover crop to become a weed if it is not terminated at the proper time,” Morgan said. “And you want to give it the most optimum time to release those nutrients or fix the nutrients it needs to.”
Bain said that along with growing a cover crop to improve soil health, a soil sample should be taken to give a better picture of what nutrients are present and their levels.