Residue management begins in fall
With higher yield goals, higher plant populations and aggressive fertilization, growers need to manage increased amounts of crop residue to establish productive stands the following year.
This is especially important if you are planting corn following corn. Typically, soybeans can tolerate more residue than corn.
Uniform emergence is critical to optimizing yield potential in corn. The greater the delay in a plant’s emergence compared to neighboring plants, the more likely it will be a weed instead of a productive plant contributing to yield. Each day emergence is delayed, yield potential is further reduced.
• Adjust choppers or chopping headers to size residue.
• Uniformly spread residue across whole combine width.
• Consider vertical tillage to size residue before primary tillage.
Residue slows growth
Residue insulates the soil from the sun, so soil temperature under the residue can lag behind temperatures under the bare soil by several degrees for an extended period of time in the spring. A 180- to 200-bushel corn crop can produce 10,000 pounds of residue per acre. High levels of residue slow seedling growth, particularly root development, even if soil temperatures only drop as little as 3 to 5 degrees F. If root development is compromised, uptake of nutrients by the seedling is reduced. Delaying early growth and nutrient uptake affects yield.
With larger planting and harvesting equipment, it’s becoming more important to pay attention to chaff spreaders and chopping equipment. Uniform distribution of residue may become difficult with larger row-crop harvesters. Residue needs to be cut and sized so it can be broken down more rapidly and spread uniformly across the swath of the combine.
Chop stalks to size the residue for better incorporation with tillage. A traditional stalk chopper needs to run carefully so residue is drawn up and chopped well.
Some growers use corn headers with built-in choppers to save a chopping trip prior to tillage. Adjust these headers so residue is spread uniformly. There are instances when some chopping headers have spread a heavier swath in one direction causing excess residue to lie on certain rows. The rows with excess residue have seedlings which are delayed in development. The delay in development carries on through the rest of the year and is noticeable with strips of plants tasseling at different times and, therefore, maturing at different times.
Vertical tillage equipment, employing narrowly spaced ripple coulters, has come on the market to better handle the sizing of residue prior to the deep primary tillage. These tillage tools require high horsepower to pull them at speeds of 9 to 10 miles per hour for most effective sizing of stalks and root balls.
Livestock producers can reduce the residue load in fields that are going to corn next year by baling excess corn residue for bedding.
Heavy soils in fairly flat fields where erosion has limited risk still may benefit from moldboard plowing to bury the residue.
Take soil tests before tillage so fertilizer can be incorporated with the primary tillage.
Fall residue management allows producers to manage the residue at planting time using trash-whippers on the planter to clear a 6- to 10-inch path in front of the row units. These residue-free strips allow the soil over the rows to warm up compared to the soil between the rows.
Tiffany is an area agronomist for Pioneer Hi-Bred in Spicer. Contact him at firstname.lastname@example.org.
Residue impact: Heavier residue (in middle) reduces vigor of seedlings compared to seedlings (on right) where residue is less.
The right tool: Vertical tillage tools employ narrowly spaced ripple coulters to size stalks and root balls.
This article published in the September, 2010 edition of THE FARMER.
All rights reserved. Copyright Farm Progress Cos. 2010.