Better tilling for those willing
Drought, increasing costs may encourage conservation tillage
Increasing production costs and prolonged drought should provide Texas producers with more of an incentive to use conservation tillage techniques, said Texas AgriLife Research and Texas AgriLife Extension Service experts.
"Conservation tillage has not been well established in many areas of Texas, but it has tremendous water- and labor-saving potential for the state's farmers," said Dr. Diane Rowland, AgriLife Research plant stress physiologist at the Texas AgriLife Research and Extension Center in Uvalde.
Rowland, who has studied the effects of conservation tillage techniques on peanut, corn and cotton crops in Georgia, is now working with South Central Texas producers to show how employing such techniques can benefit their operations.
"By definition, conservation tillage retains 30 percent or more soil cover by crop residue or a cover crop," she said. "It typically requires little or no actual tillage. Conservation tillage primarily recycles the crop residue after harvest, putting it back to work to feed new crops and improve soil productivity."
Conservation tillage can improve soil's quality and nutrient content while reducing erosion and pesticide movement, Rowland noted. It can also reduce fuel and labor costs because it requires fewer passes with tillage machinery than conventionally tilled soil.
In times of drought, conservation-tilled soil can hold on to moisture for longer periods, as well as provide faster and more thorough moisture infiltration when it finally rains, she added.
"Many Texas growers have tried some type of conservation tillage, but may not have used the technique to its full benefit," she said. "Conservation tillage has been proven effective in many other parts of the country and can be equally useful in Texas."
Information from the Conservation Technology Information Center, a national non-profit headquartered in West Lafayette, Ind., indicates conservation tillage can reduce erosion by as much as 90 percent when contrasted with intensive conventional tillage. It also states that reducing erosion also reduces phosphorus seepage into the water table and helps convert chemicals used for crop production and protection into carbon and other basic components.
"There's no doubt that conservation tillage provides benefits during drought conditions and also improves the overall quality of the soil," said Angie Williams, center project director. "This comes from data we have collected from farmers throughout the U.S. over many years using our crop residue management survey."
Rowland said while there are different conservation tillage techniques, a minimum-till method known as strip-till may provide the greatest benefit to most Texas farmers.
Strip-till combines the benefits of no-till and conventional till techniques. Narrow strips are created where seeds can be planted and fertilizer can be applied, and undisturbed residue is left between the rows.
"We've already tried no-till with oats, planting them after harvesting peanuts, and that's worked out pretty well," said Ted Outlaw, who has been farming east of Devine for more than 30 years. "For the first time this spring, we'll be trying strip-till on a 33-acre section of peanuts, planting them using the oat stubble."
Outlaw said the sandy soil in his area lends itself well to strip-tilling, and he expects the technique will save water.
"With more and more people needing water, it's important to find new ways to get the most out of the limited water resources available," he said. "Conservation tillage will help."
At Stiles Farm in Thrall, located in the Blacklands region of Central Texas, trials comparing no-till, strip-till and conventional-till have been ongoing for the past five years.
"We've been looking at the difference in tillage practices on cotton, corn and grain sorghum crops in the Blacklands," said Archie Abrameit, the farm's manager and AgriLife Extension specialist.
Abrameit said the strip-till method used in these comparisons produces strips no more than 10 inches wide, which are then seeded and fertilized.
"The residue conserves moisture, reduces erosion and feeds the roots," he said. "It also makes it easier to plant the seeds and more precisely apply the fertilizer."
The farm's tillage trial results from 2003-2007 show that strip-tillage has either maintained or improved crops and/or has increased net income from the crops--after factoring in tillage trips, planting, spraying and harvesting costs at standard rates for the region.
For nearly 30 years, the Texas AgriLife Research and Extension Center in Corpus Christi has been conducting studies of conservation and traditional tillage under non-irrigated conditions in the state's Coastal Bend region. Six different tillage methods have been employed in two of the areas' major soil types--Orelia sandy clay loam and Victoria clay.
Comparisons have been made to determine the effects of long-term tillage variables on selected soil properties, including organic carbon and microbial activity, as well as crop yields, said Dr. John Matocha, AgriLife Research lead investigator for the center's ongoing conservation tillage study.
"What we have found through our studies is that in this region conservation tillage is a viable alternative to conventional or deep tillage for cotton, corn and grain sorghum," Matocha said. "No-till is more successful for the swelling and shrinking clay soils such as the Victoria. And the three years of study we've done on strip-till so far shows it compares well to conventional tillage."
He added that cotton and corn crops in the Coastal Bend region tend to produce better than grain sorghum when employing conservation tillage techniques, especially no-till, due to advancements in herbicides and weed control.
Opponents of conservation tillage, however, have identified soil compaction, drainage reduction, planting delays and disease or insect carryover from crop residue as potential negatives.
"You may need to till with a chisel every few years to reduce compaction from harvesting equipment and, with some conservation tillage methods, especially no-till, you may need to apply soil insecticides on grain crops a little more often," Matocha said. "But the advantages far outweigh the disadvantages and costs."
More information on conservation tillage can be found in publication B-6189, "Best Management Practices for Conservation/Reduced Tillage," which can be downloaded free from the AgriLife Bookstore website: http://agrilifebookstore.org/.