Reduced tillage systems come in about as many forms as there are farmers who find ways to modify them to fit specific management systems, field conditions and crops. Conservation tillage also offers significant benefits for moisture management, erosion control and soil health.
“Tillage definitions have changed over the years,” says Texas A&M professor and Extension soil chemist Tony Provin.
Provin, speaking at the Stiles Farm Field Day in Taylor, Texas, said conventional tillage continues to feature a “clean seedbed, but conservation tillage comes in a thousand different versions as farmers tweak a system until they find something that works.
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“No-till has its place,” he added, “but that doesn’t mean never tilling.”
Provin said conventional, reduced-till and no-till systems all have advantages but a few shortcomings as well.
Conventional systems provide better residue decomposition and soil warming, he said. But erosion, operation costs and reduced soil structure pose problems.
Reduced-tillage systems offer reduced cost, less erosion, and potential for enhanced soil structure. Disadvantages include equipment costs and residue management.
No-till also comes with reduced operating cost, the least potential for erosion, and the greatest long-term improvement to soil structure. Residue management, slower decomposition, potential for initial lower yields and problems in wet years are shortcomings.
Soil structure, Provin says, should be a significant consideration for Blacklands farmers. “The goal for a crop is to provide nutrients and water,” he said. “Poor soil structure will result in water pooling even after a light rain, compaction, soil that’s hard or powdery when dry, limited root development and erosion.
Root development is important for soil and plant health. Poor soil structure restricts roots and should be modified, Provin said. “Soil test is the first option to evaluate how to improve soil structure. Nutrient level is also the easiest thing to modify. Scout for compaction during soil sampling and minimize traffic on moist soils.”
Influence of tillage
“Tillage systems influence long-term soil health,” he added.
Blacklands farmers should evaluate tillage, depending on fields and soil conditions. “Soil moisture—dry versus wet—is important. No-till systems have problems when planting in wet, cool soils. They are superior in protecting soil from erosion, and they enhance soil aggregate stability.”
Provin recommends a hybrid system that offers advantages of conventional tillage with the long-term benefits of no-till. Strip-till may be the answer. “It’s the best of both options.”
Strip-till uses a 6-inch to 10-inch wide clean strip tilled prior to planting. The rest of the soil surface remains protected by old-crop or cover crop residue. The clean strip allows soil in the planting zone to warm more quickly and also permits band fertilization.
Provin said farmers opting for strip-till should be prepared to control winter weeds.
“Strip-till reduces fuel costs, has a limited tilled area and reduces moisture evaporation.”
Provin says farmers interested in switching to a strip-till system might be wise to start small. “Try the practice on 10 percent to 15 percent of the acreage, across the top of slopes. That reduces runoff from the top into the lower areas. Continue adding strip-till down the slope over time.”
He said the advantages of reduced tillage are well-researched, especially for water capture and conservation, soil preservation and soil health. “The key is economics. If the practice is not economical it is not sustainable.”