By: Ken Panchuk, PAg, Provincial Specialist Soils
Fine chopping and uniform spreading of straw and chaff is a critical first step in all zero-till or min-till seeding systems. This critical first step protects the soil from wind erosion while allowing the ease of seeding the next crop and keeping the soil moisture near the surface for that ideal seedbed.
Fine cut straw choppers are now the standard in the industry, allowing the finely chopped straw and chaff to be spread uniformly over the width of the cut. These high-performance choppers require regular maintenance to effectively handle a variety of crop types under variable harvest conditions. Servicing the flails and knives prior to harvest ensures that the straw chopper will do the job effectively and efficiently and without downtime during harvest. This is particularly important for flax, which has residue that is more difficult to chop.
Producers have other options for managing crop residues, such as the use of straight cutting headers or stripper-headers to leave the stubble as tall as possible. If moisture conservation in drier areas is the focus, then the stubble is left standing as tall as possible to catch snow and conserve moisture. Tall-stubble technology that also involves seeding between the rows of standing stubble will further help conserve moisture. It also usually results in increased yields in the Brown and Dark Brown soil zones, where soil moisture reserves are sometimes limiting.
If fields have very high residue amounts, consider a “residue manager with fixed knives,” which is a specially designed type of rotary mower that can finely chop and shred heavy residues. The residue manager can be used late in the fall or early spring. This creates flexibility in leaving the stubble standing to catch snow or, if the soil is recharged with moisture, to shred the residue in fall to reduce snow trapping. Also, the use of the residue manager leaves the stubble roots anchored to prevent soil erosion.
Some high-biomass crops need just a little more residue spreading, which can be accomplished by heavy harrowing during a dry day to help distribute the finely chopped straw and chaff.