Charles Stichler, Texas A&M agronomist at Uvalde, Texas, usually comes up with a pithy quotation or two that puts a little perspective on the message he's trying to deliver.
For instance, at the recent Conservation Tillage, Cotton and Rice Conference in Houston, Texas, he reminded his audience that: “Good judgment comes from experience and experience comes from bad judgment.”
He and other speakers at the eighth annual gathering of folks involved in or interested in reduced tillage systems hope to short circuit some of that bad judgment before it takes too big a chunk out of production. Stichler took a look at what he and others have learned about conservation tillage practices in central and south Texas.
“Conditions here are different from those in the Midwest,” he said. “We have a longer season and crop residue continues to decompose after harvest and after winter. Consequently, we have less residue and mulch at planting time.”
Temperatures, he said, don't drop to below 55 degrees and stay there, as is the case farther north. Colder wintertime temperatures stop decomposition.
“We also have more fall rains and little moisture in winter, and we're often dry at planting time.”
Stichler said strict no-till systems are not as useful in central and south Texas as they might be in less-temperate climes. “We often need a seedbed to pull down to find planting moisture.”
Cotton and grain sorghum crops continue to grow after harvest, so farmers have to either disk them up or kill vegetation with herbicides. With conservation tillage, herbicides get the nod. “Glyphosate and phenoxy materials work well,” Stichler said.
Winter weeds also create challenges for Southern reduced tillage practitioners. “We have to control winter weeds in south Texas,” he said. “For one thing, cutworms can be a problem in winter. Moths will find fields with green matter (even if it's a weed crop).”
Cover crops are not as effective in south Texas because of moisture demands. “We can irrigate a cover crop, but that adds to the expense,” he said. Timing termination also creates challenges.
Other reduced tillage challenges include soil compaction, especially with clay soils and moderate temperatures, without freezing and thawing extremes to keep soil loose. “We like some form of strip-till to loosen up the soil,” he said.
Corn may be the best crop for novice con-till farmers. “It's the easiest to start,” Stichler said. “We plant corn fairly deeply, and plants can push down to moisture. We also can plant early, when moisture is more available.”
Stichler said corn offers a number of herbicide choices for weed and grass control. “And because the plant dies after harvest, we don't have to kill it.”
Grain sorghum offers more challenges. Seeds are smaller, so stand problems could be more troublesome. “Because we need to plant later, we run the risk of drought conditions. We need to build a little bed for grain sorghum so we can knock it off to find moisture.”
Herbicide selection for grain sorghum is more limited than for corn. “We kill grain sorghum as quickly as possible with glyphosate,” he said. “That can occur either just before or just after harvest. Root crowns and stubble resist decay, too,” he said.
Overall, grain sorghum in a reduced-tillage program demands more management and more work than corn, Stichler said.
Cotton creates a bit more management stress. “We plant later, as late as the first of April in Uvalde but as early as February in the Lower Rio Grande Valley. Soils are drier in many areas, so we depend on a planting-time rain or beds to hold moisture.”
Temperature plays a critical role as well. Seedling diseases can cause significant losses in colder conditions. Stichler said a small bed creates a warmer environment for emerging seedlings.
“Cotton has difficulty pushing crust to emerge,” he said. “Planting flat may result in silt burying seed even deeper. A bed makes the seed shallower. Water may remove some of the soil.”
A viable stand becomes even more important with transgenic seed, he said. “Farmers are lowering plant populations to two to four seed per foot of row. We can't afford stand problems, so we wait for good soil conditions before we plant.”
Transgenic cottonseed, including Roundup Ready and Liberty Link technology, provide “good tools” for conservation tillage, Stichler said.
“We need to kill cotton stalks as soon as possible after harvest.” That's critical with boll weevil eradication programs that demand stalks be destroyed by a set date to prevent weevil reproduction. A 2,4-D application usually takes care of the stalks.”
Cotton and cover crops do not work as well in central and south Texas as they might elsewhere because they need “too much moisture. Winter weed control, especially henbit, is also important.”
Stichler said growers sometimes question whether to shred cotton or grain sorghum stalks after harvest or to leave them standing. “I recommend shredding unless a farmer has a good residue handler,” he said. “Shredding distributes the residue evenly and creates soil mulch that prevents erosion.”
He also recommends creating a small bed after harvest. “Then leave it alone in winter.”
He likes strip-till or ridge-till, especially in clay soils.
Stichler said a good conservation-tillage planting rig would consist of a stalk chopper, followed by a fertilizer coulter, then a sweep bedder, a furrow diker, and a bed conditioner. That accounts for only one trip across the field.
“Controlled traffic in reduced tillage systems is a must,” he said. “Also, rotational tillage is a good idea. Use a conservation-tillage system for two or three years and then consider chiseling to check compaction.”
He said con-till farmers need several different closing wheels, changed according to soil moisture at planting.
Fertilizer placement also bears consideration. Stichler said banding pays dividends in several ways. “We get a 30 percent savings by applying fertilizer in a band. As energy prices go higher, that savings will only increase. We also reduce potential for leaching if we band fertilizer instead of broadcasting.”
He said a pop-up fertilizer works well for corn and grain sorghum but not for cotton.
And he offered one more tidbit of advice for anyone new to conservation tillage. “Plan for the worst and hope for the best.”
The annual Conservation Tillage, Cotton and Rice Conference is sponsored by Mid America Farm Publications. Farm Press Publications is a co- media sponsor.
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