Converting row-crop production from conventional tillage to strip-till plus a winter cover crop could save soil and money, says Jamie Foster, Texas AgriLife Research forage agronomist at Beeville, pictured at left.
She came up with the idea shortly after moving to South Texas two years ago, and seeing topsoil being blown away.
“I wondered why people were producing crops the way they were,” she says. “I thought that incorporating strip tillage with a legume cover crop in the winter might be a good solution to a lot of the problems we are facing. Here in South Texas, those problems are primarily moisture availability because of the drought situations and low rainfall in general, and also rising fertilizer prices.”
The price of nitrogen in fertilizers has increased as fuel prices have increased, says Foster.
“Phosphorous and potassium fertilizers also have their limitations,” she adds. “They are limited resources, and we’re competing with India and China more and more every day for these other two primary resources.”
She’s now working to identify legumes adapted to the area’s growing conditions, including medics and clover, which have the potential to serve as cover crops.
“As off-season cover crops, the legumes have the potential to hold the soil in place on windy days and also improve the nitrogen cycling and availability. Legumes do take a lot of phosphorus to grow, but as they degrade in the soil, they leave some behind that’s available for the row crops that follow its production, be it cotton or sorghum.”
As the cool-season legumes grow, they can be harvested periodically for hay for added income or even grazed, she says.
In conventional tillage, the entire field is tilled between crops; in strip tillage less than 70% is tilled as growers leave behind 6-18”- wide strips of untilled soil. Growers in South Texas leave their fields completely bare during the off season for a couple of reasons, says Foster.
"It is easier to manage a tilled field, and other states have restrictions against conventional tillage. Or, they offer incentives to not till a field completely to reduce runoff. And there’s a perception that a clean field is a better, neater field.”
This fall, she’s starting legume research demonstration plots in Uvalde and Beeville to determine which perform best.
“We’ll do the research and develop data before making any recommendations,” she says. “Growers are not likely to change their practices until they know this strip tillage, legume system will improve yields and increase profits.”
She adds that the changing economic times are making the system more attractive to growers.
“When fertilizer and fuels were relatively cheap and moisture was abundant, it was easy to continue with conventional tillage, or no-till. But with those prices rising so dramatically, so is interest in this new system. Strip-till equipment is available and there are now modern legume cultivars to choose from.”
The advantages of switching are too enticing to ignore, she believes.
“Lots of problems, both environmental and financial are solved. It reduces erosion, soil-moisture loss and nitrogen loss. It improves organic matter in soil, which means the soil is holding carbon. That reduces carbon emissions, greenhouse gasses and global warming. Plus, hay sales and grazing can increase incomes. That’s a lot of wins.”