Spring tillage is a tradition steeped deeply in American agriculture. But more and more farmers are realizing that this iconic tradition is costing them -- in more ways than one.
Tillage comes at a high price. There are the known expenses like increased fuel and labor costs. But according to Rick Bednarek, state soil scientist with USDA's Natural Resources Conservation Service in Des Moines, the bigger, long-term cost may be the loss of soil health and function resulting in lower yields, higher input costs and reduced drought resiliency for Iowa farms.
Tillage destroys soil structure, making soil vulnerable to erosion, compaction and runoff
"Tillage is incredibly destructive to the soil structure and to the soil ecosystem," says Bednarek. "Healthy soil is 50% air and water, which is made possible by the pore space in the soil and 50% mineral and organic matter. But tillage collapses and destroys that structure, making the soil vulnerable to erosion and compaction."
The possibility of another dry year should also have producers rethinking their use of tillage, says Bednarek. "Because it destroys organic matter and soil structure, tillage actually reduces the soil's infiltration capacity," he adds. "Studies have shown that each tillage pass can release a half-inch of soil moisture from each acre. Tillage tends to limit the availability of water in the soil, and that could prove very costly during those long, summer dry spells."
Fortunately, more and more producers in Iowa are farming with systems to build soil health. "Using a suite of conservation practices, like no-till, nutrient management, and cover crops," he notes, "they're keeping living plants in the soil as long as possible and they're keeping the soil surface covered with residue year-round."
Increased water holding capacity of soil reduces runoff, which helps minimize nutrient pollution of streams, ponds and lakes
Also, Bednarek points out, the benefits of improved soil health extend beyond the farm. "Producers who improve the health of their soil are also increasing its water-holding capacity, which reduces runoff that can cause flooding. Improved infiltration of water into the soil in the field keeps nutrients and sediment from being carried off-site into nearby lakes, rivers and streams," he says.
Farmers who are interested in learning more about the basics and benefits of soil health or receiving technical and financial assistance to implement a soil health management system should contact their local NRCS office. Additional soil health information is available at the NRCS website.