Et cetera : Avoid Fall Tillage To Maintain Soil Productivity

    Tilling fields this fall could have a lasting impact on your soil’s long-term productivity, according to Barb Stewart, state agronomist for USDA's Natural Resources Conservation Service (NRCS) in Iowa. Reducing tillage minimizes the loss of organic matter and protects the soil surface with plant residue. Tillage can break up soil structure, speed the decomposition and loss of organic matter, increase the threat of erosion, destroy the habitat of helpful organisms and cause compaction. Each of these potential outcomes negatively impact soil quality. A soil’s performance is directly related to a soil’s quality or health. A healthy soil will do a better job at: resisting erosion; cycling crop nutrients; supporting root growth; infiltrating water; and sequestering carbon, she said. “One of the most crucial of these decisions affecting soil performance is a producer’s residue management or tillage practices,” said Stewart. “So producers who till the soil this fall could already be reducing their yield potential for the following year by damaging the soil performance on their farm.” Tillage negatively impacts the following: Soil Structure: A healthy soil structure provides the framework for good water infiltration, reduced runoff and root development. Organic Matter: The amount of organic matter in the soil is probably the number one indicator if the soil is at its peak performance. Tillage aerates the soil, triggering increased biological activity, resulting in rapid decomposition, loss of soil organic matter and release of CO2 into the atmosphere. Basically, tillage promotes the “burning” of organic matter. Habitat: Tillage can destroy the soil structure needed for good habitat for the microorganism’s living in the soil. Most of these organisms live in the top two inches of the soils surface, so even the most shallow tillage operations can have damaging effects. These microorganisms play an important role in nutrient cycling and helping decompose organic matter. Compaction: Tillage can damage soil structure making it more vulnerable to compaction. This compaction reduces the amount of air, water and space available to roots and soil organisms. When this space is removed, runoff increases, root development is impacted as well as the fertility of the soil. So before tilling the soil this fall, think about your soil performance, advises Stewart. “Tillage can have a lasting impact on how well your soil performs for your operation,” she said.