Perfect Timing
February 22, 2010 Southern cotton growers have been aware of the rotational benefits that grains could offer their cotton crops for decades. But when it came time to make planting decisions in 2008, a spike in grain prices translated into unprecedented acreage for corn and soybeans across the Mid-South. After two full growing seasons, cotton is finally ready to reclaim a large chunk of its lost acreage in the Mid-South. As grain and cotton experts point out, cotton’s timing couldn’t be better.
It was the Bush Administration’s ethanol mandates that began the domino effect that would change the landscape in the Mid-South. As corn prices rose, that crop naturally took up more acreage on the versatile southern soils. Once that trend took its toll on soybean acreage, those stocks fell and soybean prices rose right along with corn. In the Mid-South, cotton suffered the worst acreage hit. By 2009, Louisiana and Mississippi would produce the least amount of cotton that either state had in their respective recorded histories.
But as cotton continues to flirt with the 80 cent mark, and as corn and soybean prices subtly fade back to their medians, all signs are pointing to a cotton recovery in 2010. In January, Cotton Grower magazine released its annual Acreage Survey results, which projected a national total of just over 9.9 million acres of cotton in 2010. That number represents an almost 10% increase over the 2009 planted total. Industry experts in the Mid-South agree that cotton is poised to make a comeback.
“(In 2009) we had 230,000 acres,” says Dr. Tom Boquet, the Jack and Henrietta Jones Professor of Agronomy in the LSU Ag Center. “Are we going to do higher than 230,000 acres? I think so.”
Boquet believes growers in Louisiana have become sufficiently versatile to plant whichever crop is most profitable in any given year.
“So cotton will stay in when the prices go up. I anticipate we could have as much as 400,000 acres of cotton at times in the state, in the near future,” he says.
Mutual Benefits
And as cotton moves back on to those acres in places like Louisiana, the soil conditions could be just right.
While soybeans and cotton can be natural hosts to cyst and reniform nematodes, corn is not susceptible to either of the pests. In Louisiana, where reniform nematodes can wreak havoc on a crop, this makes corn a highly beneficial rotation option.
“To control reniform nematodes, the best way is to rotate susceptible crops like cotton with the non-host crop such as corn. You can grow a year of corn or sometimes you can grow two years of corn and when you come back growing cotton again you won’t have any nematode damage,” Boquet says.
Another benefit cotton will see as it inherits soil from grain crops is a replenished nutrient base. Soybeans, in particular, leave a host of usable nutrients in the ground, which prove beneficial to both corn and cotton.
“Soybeans don’t utilize nearly as much nutrients as what a corn crop does,” says Trey Koger, Soybean Extension specialist with Mississippi State University. “A corn plant uses a tremendous amount of phosphorous to make a grain crop. The nutrient cotton uses the most is potash, outside of its nitrous requirements. Soybeans being third, don’t utilize as much overall phosphorous and potassium as what a corn crop does.”
While corn may soak in valuable phosphorous nutrients, it also leaves behind the benefits of its crop residue. According to Boquet, as the residue is ‘mineralized’ into the soil, bacteria and fungi begin to break it down. The process leaves valuable nutrients in the soil. And the residual organic activity isn’t the only thing a corn crop can leave behind for cotton.
“There’s also just a fertility issue there particularly for the cotton. If you fertilize the corn with nitrogen, and use the high rates it uses, we find when we come back with cotton we don’t need as much fertilizer or nitrogen. We can cut nitrogen use anywhere from 30% to 50% just because of the residual effect,” Boquet says.
A Bigger Tool Box
And as the Mid-South braces for its own battle with glyphosate resistance, the grain rotation options could once again prove beneficial. According to Koger, corn is a crop that offers a wide variety of weapons in the battle against resistance.
“Corn is a great option for trying to prevent, circumvent, or manage glyphosate resistant weeds,” Koger says. “In corn we have things like atrazine, we have things like Callisto. There are herbicides that we can use only in corn that we cannot use in cotton and soybeans. We also have 2,4-D or Dicamba that can be used over the top of corn to control things like horseweed or pigweed.
“(Corn and soybeans) give you a bigger tool box to utilize different herbicides to manage glyphosate resistant weeds than what you have in just cotton alone.”
Raising the Yield Bar
Of course, in addition to the input cost cutting measures these crops provide, they also benefit each other in another important way: increasing yields.
“The yield increases we get from rotating just corn and cotton are in the neighborhood of 20%. So if you’re looking at a 2 bale crop, which would be about 1,000 pounds of lint, you could increase it up to 200 pounds of lint per year on each acre.
“And we have gotten as much as 25% yield increase when we’re growing two years of corn and then planting cotton,” says Boquet.
As many growers across the South devote more acres to cotton after a two year absence, that 25% could be a welcome sight.
Add 3 photos:
A corn harvest can leave behind organic material that is beneficial for cotton.
Grain bins have become a familiar sight on the Mid-South landscape.
A corn and cotton rotation system can lead to increased yields for both crops.
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