Editor’s note: Pigweed, a curse in the Southwest for peanut, cotton and other row crop producers, vexes Mid-south farmers’ patience as well. Finding an efficient and effective way to control the weed offers a challenge, regardless of where the farm is. A Mississippi peanut farmer is using a winter cover crop as part of his weed management program. Southwest producers might find the practice useful as well.
One Mississippi producer may have found a way to rid his farm of pigweed, that prickly, fast-growing, troublesome weed dotting the Delta’s landscape. The solution, according Mississippi producer B. Jones, lies in a winter mix of beneficial vegetation.
When Delta F.A.R.M. (Farmers Advocating Resource Management) kicked off the Mississippi Healthy Soils Initiative in the fall of 2014 with the aim of demonstrating and evaluating better ways to build healthy soils, B. Jones and his brother, Will, were already believers in the benefits of a winter cover crop. What they didn’t know then, was how much pigweed control that cover crop would offer.
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The Jones brothers, who farm in Mississippi’s Holmes and Humphreys counties, began planting winter cover crops a few years ago, both for the soil benefits and for the promise of better weed control. Their initial crop mix was a seed blend out of west Tennessee that included clover, cereal rye and tillage radishes. While the clover provides a residual nitrogen benefit, especially for a spring corn crop, the tillage radishes aid in soil aeration and the cereal rye assists with weed control.
Cereal Rye a Workhorse
According to University of Arkansas researcher Trenton Roberts, “As far as cover crops go in the Mid-South region, cereal rye is a workhorse that is hard to beat in terms of the benefits that can be gained for the relatively low input cost that is required to establish and manage it as a cover crop.”
The conservation practice impressed the Jones brothers enough to continue planting cover crops, with a few creative adjustments of their own. Beginning in 2013, Jones created their own cover crop blends to best fit the needs of each field.
In 2014, on all freshly leveled land, or land with hardpan soils, B. Jones made the decision to drop the clover rate in his cover crop mix. “I wanted as much rye as I could get in my budget to help with the weeds. Our goal was to control pigweed and break up that hardpan. The cereal rye seems to really help with weed control. Even when it is dead, it keeps the light out, which helps control pigweed,” Jones says.
“In most cases the name of the game for cover crop success is biomass production,” says Roberts. “Cover crop biomass production is essential to achieve many of the benefits that are associated with cover crop use including erosion reduction, weed suppression, nutrient retention, crusting prevention and increasing soil organic matter. Cereal rye is a huge biomass producer with little to no input cost.”
While sticking to a $35-per-acre budget, Jones also tripled the rate of tillage radishes in his cover crop mix to break up the hardpan soils. While Jones didn’t have what he considers “the best” stand of radishes, he says the cover crop was a worthy investment. “The amazing thing is where I’ve put it, the pigweed population is greatly diminished,” he says.
Adjusts Mix for Field Needs
This year, Jones will again alter his cover crop planting ratios according to the needs of each field. Because he didn’t land-level any fields in 2015, he will cut back on the percentage of tillage radishes he plants. He’s targeting weed control in peanuts with an increase in the percentage of cereal rye planted, and will add in some winter wheat or oats for the additional ground cover benefits those two crops may provide in terms of weed control.
Jones plants the cover crops into sandy and sandy loam soils that will be seeded for soybeans, peanuts, cotton, and corn next spring. While most crop fields are planted from turnrow to turnrow, the cover crop on Jones’ peanut fields is planted along the edges of the fields where pigweed pressure and hog and deer populations are high.
He aims for an early September planting date, but weather and harvest timing often alter that date. “The first of September is the ideal time to plant cover crops because it gives the tillage radishes adequate time to grow to maturity,” Jones says. “Much of our crop is still in the ground the first of September, however, so we are aiming for a cover crop planting window of Sept. 1 to Oct. 1. It’s a real timing issue.”
Most of Jones’ cover crop is broadcast onto the soil’s surface, but he may drill some seed into the soil additional time presents itself. He also has planted the cover crop on beds in 30-inch rows, and he has planted them flat in soybean fields before pulling the middles for irrigation. “The rye is plentiful down in those middles where the weed pressure is highest,” he says.
Amazing Weed Control
Jones adds, “The weed control the cover crop has provided in all three crops (peanuts, soybeans and corn) has been amazing, especially with regards to pigweed. The rye appears to greatly suppress our pigweed pressure.”
Despite the fact the majority of tillage radishes die from winterkill, Jones does terminate the cover crop with a herbicide burndown. Fields that will be planted to corn are terminated one month prior to planting, and both soybean and peanut fields are terminated six weeks prior to planting.
“I am still experimenting with this cover crop system, but so far I’ve been very impressed with the weed control benefits the system provides,” Jones says.
Since Delta F.A.R.M. kicked off the Mississippi Healthy Soils Initiative in the fall of 2014, more than 8,500 acres of cover crops are being planted by 30 farmers on more than 120 fields in Mississippi.
An association of growers and landowners, Delta F.A.R.M. (Farmers Advocating Resource Management) strives to implement recognized agricultural practices that will conserve, restore, and enhance the environmental resources of northwest Mississippi. Founded in 1998, Delta F.A.R.M. has enrolled over 1.3 million acres into its voluntary conservation program, which promotes and documents conservation practices implemented on private lands in the Mississippi Delta.