Plant residues are a precious resource in reduced tillage, providing enrichment of soil organic matter, moisture and physical characteristics, microhabitats for crop seedlings, and reduced weed germination.
Good residue management exploits these benefits:
• Fit the combine-harvester with a straw/chaff spreader
• Spread straw and chaff evenly
• Harrow the straw in the fall or spring before seeding
The key to harrowing straw:
• Speed of the tractor-sufficient to spread the straw evenly without bunching
• Timing-spring generally, or fall depending on the specific situation
• Dry soils provide better medium for straw handling
Factors that affect residue management:
• Crop type-heavy crops providing more straw are a positive factor
• Width of cut-affects the spread pattern; aim for an even spread
• Stubble height-tall stubble or alternate height stubble increases moisture retention and snow trapping
• Straight cut vs. swathed-straight cut may give higher stubble; swath may give more straw
• Straw quantity-some crops produce more straw than others; canola mustard, short vine pea and lentils produce less straw and it tends to break down easily
• Conventional vs. rotary combine-rotary produces shorter straw and may not require chopping
• Straw choppers and spreaders-under high yield wide swath conditions, original equipment choppers and spreaders are often inadequate
• Chaff spreaders-chaff spreading is essential
Farmer experience: (4 farmers share their experiences)
• Farmer A uses a 50 ft Flexi-Coil heavy harrow with a 360 hp tractor in the spring. According to this farmer, fall harrowing creates problems at seeding.
• Farmer B bales the straw, which he takes to a feedlot, and stubble grazes livestock.
• Farmer C uses an air blowing system on the combine to spread the chaff.
• Farmer D blows the chaff into a high dump silage wagon trailing behind the combine