Cotton’s environmental footprint
Jun 30, 2009 9:47 AM,
By Cary Blake
Farm Press Editorial Staff
Despite its naysayers, the U.S. cotton industry creates a positive environmental footprint worthy of bragging rights.
“If you look at U.S. cotton’s energy footprint, the cottonseed in a bale of cotton contains more energy than the energy required to produce the cotton and gin the bale,” according to Ed Barnes, director of agricultural research with Cotton Incorporated, Cary, N.C.
Energy inputs for cotton include diesel fuel, nitrogen, herbicides, and irrigation among others. Barnes spoke at the joint annual meetings of the Arizona Cotton Growers Association and the Arizona Cotton Ginners Association in Rio Rico, Ariz.
Barnes rattled off praises for the natural fabric. Cotton is grown on less than 3 percent of the world’s agricultural land. Cotton yields have increased on average over the last three decades, showcasing improved land use efficiency.
Among cotton’s naysayers, Barnes says, is the Lenzing company, which manufacturers man-made cellulose fibers. The rayon maker hails itself as nature’s friend, with minimal negative impact on the environment. Lenzing points a finger at the cotton industry as an environmental polluter. Barnes maintains that studies and publicly-released data sets indicate otherwise.
“In the cotton production process, more greenhouse gasses are sequestered in the fiber and soil than are emitted into the atmosphere,” Barnes noted. “There’s more carbon in the fiber than the cotton industry emits in growing and ginning the fiber.”
Water use in cotton is a tougher sell with the public and regulators. About one-third of the U.S. cotton crop is grown with irrigation. New drought-tolerant cotton varieties are water-misers.
“In Arizona, people want to claim that cotton is a big water user, but we’re not compared to other crops,” Barnes told the grower/ginner crowd. “Arizona cotton growers have some of the best yields in the country. Growers have optimized land use efficiency. There’s a lot to be said for irrigated systems.”
Barnes referenced USDA data from 2007 that foliar insecticide is not applied to one-third of the U.S. cotton acreage; in part due to Bt technology.
Some of the latest positive spins on cotton are from the results of the Natural Resource Survey of U.S. cotton growers conducted by Cotton Incorporated and the Cotton Board last year.
The survey’s purpose was three-fold: promoting natural cotton using fresh data; examining the cotton industry’s greatest research needs to better reflect where research dollars are spent; and gaining a benchmark on current production practices.
About 1,300 valid responses were received representing about 16 percent of U.S. cotton acreage, plus 1.7 million acres of rotational crops. More than 100 growers from the Far West submitted responses.
Survey results indicate about 80 percent of U.S.-grown cotton is rotated with other crops. In the Far West, about 90 percent of the cotton is rotated with alfalfa, wheat, corn, vegetables, and orchard crops.
“Many people don’t believe cotton is rotated,” Barnes said. “This is a good statistic to show that cotton is not just monoculture; there is a lot of variety out there.”
The survey revealed about 75 percent of the growers reduced pesticide use by 40 percent or higher over the last decade. Foliar insecticides were not applied on more than 40 percent of the farms. About 30 percent of the acreage received no insecticide treatment.
The survey results revealed needed improvements in scheduling cotton irrigation. About half of the growers responding to the survey make irrigation decisions by visual assessment. Less than 10 percent utilize monitoring tools or evapotranspiration.
Irrigation scheduling is tricky in the West, Barnes says. “We will try to direct Cotton Incorporated’s research to develop easier irrigation tools that better achieve farmers’ needs.”
To produce cotton from “dirt-to-bale,” the energy to create fertilizers represents about one-half of the total energy used in non-irrigated production. In irrigated cotton, drawing 40 inches of water from a 300-foot deep well requires about two-thirds of cotton’s energy demand. “Water pumped from any depth can quickly dominate the energy footprint,” Barnes said.
About 7,600 BTUs of energy are required to produce 1 pound of cotton for typical production practices in the U.S., Barnes says.
After a year of lower energy prices, the cotton researcher predicts the return of higher energy costs. “Energy will get expensive again,” Barnes said. “We have a break right now in prices. I think what we saw last summer was a hint of what the future holds for us. Anything the cotton industry can do to reduce energy use will lower our greenhouse gas emissions and production costs.”
e-mail: cblake@farmpress.com
