Ideally, crop residue management begins at harvest with proper distribution of residue behind the combine. It continues with subsequent residue cover measurements after each trip (fall or spring tillage operations) and finishes with measurements after planting to ensure that desired levels are achieved.
Between harvesting and planting operations, a large portion of residue cover may be lost from overwintering or from burial by tillage equipment for those not using no-till systems. Because overwintering losses are nearly impossible to control, crop residue management strategies typically concentrate on limiting tillage practices to maintain high levels of surface cover.

Goal: an evenly- spread blanket of residue.

Crop residue remaining after harvest
The amount of crop residue cover that remains behind a combine depends primarily on type of crop and crop yield. Row spacing can also influence cover but to a lesser degree than the crop grown. In nearly all crop production systems, residue cover following harvest is 70% or higher. Exceptions are crops where large quantities of biomass are removed (corn silage), low residue-producing crops (soybeans), or below-normal crop yields.
Typically, there is little or no difference in residue cover remaining after harvest among varieties of a given crop when yields are normal or above-normal.

Combine adjustments and accessories
Wider combine headers (greater than 15 feet) and higher residue production with new crop varieties are two reasons a well adjusted combine is critical to high-residue farming. Without special attachments or modifications, combine headers of 20-30 feet or more are not adequately equipped to spread today's larger volumes of residues uniformly.

Common problems
The most common mistake made in the harvesting operation is to allow crop residue to accumulate in windrows behind the combine. This accumulation causes the soil under the windrows to stay wetter and cooler which can limit early season plant growth. Planting into windrows can result in uneven stands because the seeds take longer to germinate and grow, resulting in significant yield reductions.
Other problems associated with improper combine residue distribution include:
Unsatisfactory weed
control from herbicide
interception.
Poor performance of
planters and tillage
implements.
Increased demands on
planter equipment.
Poor seed-to-soil contact
(usually from "hairpinning"
of residue into the seed
row).
Excessive residue lying
directly over the seed
furrow resulting in an
allelopathic effect (natural
chemicals or toxins from
related plant types that
could inhibit germination
or growth).
Increased pest infestation
(from insects and rodents).
Increased weed seed
concentration.
Poor plant nutrient uptake
(from fertilizer tie-up or
interception).

These problems are usually associated with small grains, such as wheat, but the effects of concentration of residues by a combine can be a problem with almost any crop. If properly adjusted, the type of combine used (rotary or cylinder) has little influence on residue cover.
To avoid the above problems, make sure you:
Always check residue
distribution patterns of
newly purchased combines
(whether new or used)
Consider residue spreading
attachments.

Avoid windrowed residue.