Why is fall tillage so common in the upper Midwest? The reasons I am familiar with are the following: (1) the soil warms up faster in the spring, (2) it’s convenient to be able to pull into the field in the spring and plant rather than having to do any tillage, (3) tillage incorporates the corn stubble into the soil, (4) tillage “fluffs up” the soil and breaks up compaction, and (5) it looks good to “button-up” all the field work in the fall and go in to the winter with all work done.
What has made it possible to get all this work done in the fall? Fifty years ago, farmers might be lucky to get the harvest in, much less finish with tillage. The reason is that today with larger, faster equipment we can tear through the acres much faster. For example, my neighbor chisel plows corn stalks with a Steiger-Case IH quadratrack that packs somewhere between 370-620 horsepower.
So what could be wrong with fall tillage? Well, the scientists tell us the following: (1) fall tillage allows nitrate and phosphorus to flow into the watersheds (nitrate flows with tile water and phosphorus adheres to soil particles and flows with surface erosion, and (2) tillage increases soil erosion, both by wind and water, since it leaves the topsoil exposed to the elements for approximately six months.
With an alternative “tillage” system, cover crops, we retain nutrients and reduce erosion greatly. Additionally, we suppress weeds and increase organic matter on the farm. Since fall tillage would destroy the cover crop in the fall, there is no need for the large horsepower tractor on the farm. Instead, the cover crop is either seeded by plane into standing crops or seeded with a drill and tractor after harvest. If corn is the next crop, the anhydrous ammonia can be applied the following spring rather than in the fall in the bean stubble as it is done conventionally. Farmers may need a heavier no-till ready planter to plant into the cover crop residue. One example is the Kinze planters. Other companies offer suitable planters as well.