Residue Management During Harvest

REGINA - Sep 19/05 - SNS -- Growers need to pay more attention to residue management during harvest to make it easier for the next season's crops to get a good start, according to Special Crops Provincial Specialist Ray McVicar.

"As producers use minimal or zero till practices in efforts to improve soil conservation and reduce fuel costs, trash management must be approached differently," says McVicar. "Whereas, in the past, producers could dispose of the residue by incorporation into the soil through cultivation, this method is often no longer an option."

McVicar advises producers to give particular care and attention to chopping and evenly spreading residue with the combine.

"If the straw is left in piles, next year’s seedlings will be unable to grow through the residue, resulting in uneven plant stands and populations. If there is a thick concentration of residue in places, this will interfere with the ability of the sun to warm the ground in spring. Crops rely on rapidly warming soil for even germination and development. That is why spreading the trash evenly is so key."

As the ground warms up in spring, explains McVicar, it provides a heat source to the air three to four centimeters above the ground at night, providing a protective microenvironment for seedlings early in the growth process. Seedlings that emerge through thick residue or straw do not have that protection and are more susceptible to late spring frost.

McVicar says there are other advantages to chopping and spreading the straw evenly for next spring’s seeding operation.

"Poorly chopped straw might get pushed along by the seeder and reduce the effectiveness of seeding by plugging the seeder, or the openers might ride over top of the straw piles."

Pea and other pulse crops provide many benefits. They extend and diversify crop rotations, increase nitrogen availability, improve soil tilth and contribute to soil organic matter.

Pea residues break down more rapidly than the residues of many other crops, such as wheat or canola, but they must still be handled properly. Bunched and piled pea straw can cause extensive plugging of seeding equipment, explains McVicar.

"Some producers report that the use of heavy harrows can spread pea residue before seeding. But perhaps the greatest concern with pea is combine fires. There is an increased risk of fires, especially if the crop has been infected with a disease called powdery mildew."

The disease produces a fine powder that can accumulate on the hot surfaces of combines, like a manifold, where it can ignite.

"As a basic precaution, we advise producers harvesting peas to bring the water truck to the field before starting to work. It can save a lot of heartache."