AgriGold

2010 Tillage and Residue

by Jack Hardwick, CCA, March 8, 2010

Wet conditions throughout the Corn Belt during the harvest season in 2009 resulted in compaction and rutted up fields in many areas. Those same wet conditions did not allow many farmers to repair those ruts or complete fall tillage. As we approach the spring season in 2010, corn growers need to have a plan for repairing damaged fields and need to know what conditions will make spring tillage a good choice. Below are some common questions that need to be addressed.

Do I need to worry about ruts in the field? Any ruts deeper than a few inches will need to be repaired before planting can occur. Planters are not able to accurately and consistently place seed into rough field conditions, especially ruts. Fall tillage normally does a good job repairing harvest season ruts. If fall tillage was not completed, light tillage implements like disks and field cultivators should be used to level out ruts. Driving at an angle across the ruts is recommended, and more than one pass may be needed. Even after ruts are leveled, it is important to remember that compaction deeper in the soil profile, especially directly under the rut, will affect water and air infiltration, nutrient uptake, root growth, and yield. This generally causes stripped patterns of stunted, pale colored plants within the field throughout the growing season.

So why not take my chisel plow or deep ripper out there and remove ruts and compaction this spring? If we have a very dry spring and soil conditions are right, then primary tillage is still an option. However, most areas had wet soil conditions when the soil froze in the late fall or early winter. Wet soil does not lift, loosen, and shatter like dry soil does. Shanks and points cause soil smearing and destroy soil structure. Implements with lifting action form hardpan layers at the depth of tillage. This compaction can leave corn fields worse off in the long term than doing no tillage at all. If the spring is wet, it will be best to wait for dry conditions to perform deep tillage, even if that means waiting until fall 2010. Implements that lift the soil also produce soil clods when used in wet conditions. These clods can be broken up when immediately followed by a lighter tillage tool or a rainfall. If the clods dry out before the second tillage pass, or rain does not fall, it will be difficult to get the clods broken up to form a good seedbed.  Current weather conditions are going to limit most all deep tillage applications that could remove compaction, so the main focus right now should be on preparing a good seedbed for planting. 

Vertical tillage is a relatively new term in the crop production world. Many different styles of vertical tillage implements are on the market. Manufacturers of these implements claim these new tools bring many advantages in the field including: sizing and incorporating residue, including thick corn stubble; seed bed preparation in all tillage systems; faster soil warm-up and dry-out; reduced compaction; and high working ground speeds. In a wet spring, vertical tillage might be something to consider. Wetter soils should not suffer from as much compaction as lifting type implements, faster warm-up and dry-out can get growers planting sooner, and high ground speeds allow growers to cover large areas quickly. Growers have had success using vertical tillage in many different ways. As with any new technology, it is a good idea to try it out before jumping in with both feet.

Residue management will be very important in 2010. High corn grain yields also lead to high residue yields. Couple that fact with a late harvest, cool conditions, and reduced completion rates of fall tillage, and we realize that dealing with corn residue needs to be an important part of our strategy for spring 2010. Below are some corn on corn considerations for spring 2010.

Corn Residue

• Corn residue on the surface keeps the soil beneath cooler and wetter.
• Chopping stalks creates a mat on the soil surface if they are not removed or incorporated. This mat of residue hampers soil warm-up and dry-out.
• Reduced tillage systems also result in cooler soils (Chart 1).
• Properly adjusted row cleaners help provide a dry, warm, and barrier-free environment for emerging seedlings.

Nitrogen Immobilization

• Soil microbes use nitrogen (N) as fuel to break down corn residue. This "immobilized" N is temporarily unavailable for plants to use.
• Microbes are going to have more than normal residue in 2010 due to a late and cool harvest.
• Surface applying N will help "feed" microbes and well as young corn plants.
• Microbes that decompose corn residue are fueled by N in the ammonium form. Providing early N in the nitrate form can boost seedling growth.
• Refer to Nitrogen newsletter for more details.

Categories: Planting Tips

Print this page