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Tillage is a popular practice across much of Illinois and it still has its place in a high-yield management system. It also simplifies other decisions that no-tillers have to consider such as handling residue, cooler and wetter soils in the spring and more potential for seedling diseases. Tillage provides two main benefits:

• Tillage blackens and loosens the soil in the fall so it dries and warms more quickly in the spring. In heavier soils in central and northern Illinois and tighter clay soils in southern Illinois tillage is a practice that helps guarantee a good stand that emerges rapidly—which is a prerequisite to high yields.

• Tillage can help manage all of the corn residue after 200+ bushel corn, in continuous corn rotations and any cornstalks that don’t decay readily enough in the field.

Fall tillage begins with spreading residue, especially corn residue created by a 200-bushel corn crop. Cornstalks can be a headache because with today’s Bt traits, good plant health and stay green characteristics, they just don’t decay and disintegrate as rapidly as in the past.

Whether you practice conventional tillage or no-till, properly spreading residue is the start of managing it. Take a good look at the spreader behind your combine and how it is set up and operating. Distribution is very important, especially when you want bumper crops. Remember you are spreading chaff and coarse residue. Chaff is lightweight, affected by the wind and more difficult to spread. Coarser material spreads more equally using spreaders with batts.

Of course, today growers can adopt chopping corn heads which will slice cornstalks as they are pulled down through the stalk rollers. The key to residue decomposition is slicing and dicing into small pieces and fracturing the stalks and then anchoring it down with soil to introduce microbes into the material. Of course decomposition needs moisture, warmer temperatures and an available supply of active carbon, nitrogen and sulfur. Not all of these requirements are available during the late fall and winter months and this delays decay. Ever notice how the stalks from corn harvested in mid September blacken before it turns cold in the fall vs. how stalks from corn harvested in late October and November stay golden brown till spring? Winter months aren’t good for decay.

Next comes the tillage pass. Farmers till to process and incorporate residue, fertilizer and chemicals; blacken the soil so it warms and dries faster in the spring; and prepare an even seedbed for next spring.  However, fall tillage usually leaves the field rough and requires a spring finishing pass to create a seedbed. No matter what your goal, adjust and run the tool so it will help you achieve your objective for the fall.

When doing fall tillage first consider soil conditions. For tillage to work properly, soil has to be relatively dry to fracture and process residue without causing compaction. If you do primary tillage, fall is a better time because the soil is in more fit condition. Moisture is below field capacity; compaction is less of a risk, soil hasn’t frozen yet and you won’t pull up wet clods of soil. And if shearing forces do compress the soil, winter freezing and thawing and wetting and drying will break up clods and loosen compact layers, either horizontal or vertical.

Remember, tillage is about processing and incorporating residue, fracturing density layers in the soil and blackening the soil so it will warm and dry in the spring. And in the process you can prepare a seedbed. However, tillage doesn’t necessarily improve soil tilth, health or productivity. Conventional tillage tends to degrade natural soil structure while creating a temporary solution for planting the next crop.

Do you do fall tillage? If so, what are you reasons and what are the benefits you experience? Let us know in our forum.

Agronomist Dr. Daniel Davidson posts blogs on agronomy-related topics. Feel free to contact him at djdavidson@agrwrite.com.