Most proud and passionate direct-seeders tend to centre on the features of their preferred seeding operation. This discussion will focus primarily on the oft-forgotten harvest phase.
Twelve years as a direct-seeding (DS) extension agent with Reduced Tillage Linkages in Alberta finds me well-adjusted to all the notill bad mouthing that goes on over soil warming and other such residue-related woes. (My on-farm learning has caused some personal muttering, too.) A recent outcome from working as a reduced tillage agronomist is my absolute conclusion that future DS advancements will originate from a change in attitude, belief, and awareness that “no-till truly does begin at harvest.” Broadening the focus to include residue management at harvest will be coming soon to a farm near you.
STRIPPER DIARY, OCTOBER ENTRY
Camera in hand, snooping around in waste-high wheat stubble with the combine whizzing past, I quickly realized why this innovative farmer was keen about his stripper-header. My interest in this advanced harvesting system twigged a few months earlier while kneeling in similar notill stubble to explore freshly seeded canola. The focus then was mainly on his no-till seeding implement, a Flexi-coil 6000 with Barton double-shoot openers at 10-inch row spacing. It was doing a super job in tall stripped wheat, barley, and flax stubble. I could tell that a decade’s experience with angle-disc openers and different crops had taught this guy how to set and operate his machine.
STRIPPED VS. CUT
Of late I’ve been looking at how the concept of an untouched seedbed functions from a harvest standpoint. Here are some benefits of stripped over swathed stubble:
1. Generally, the taller the stubble the more snow it traps. In 2009 near Mannville, Alta., snow accumulation in fields of three-foot tall stripped stubble (SS) measured two to three times more than in 10-inch swathed stubble (SW). See photos 1 and 2.
2. Tall stubble has less snow pack. Interestingly, during spring thaw, the deep lower density SS snow actually melted as fast or faster than snow in SW due to a superior radiant effect of exposed tall stubble. In fact the last snow to disappear on SS was in wheel tracks (pre-harvest sprayer, combine, trucks, etc.), but seldom remained longer than snow pack areas where drifting frequently occurred on nearby SW fields. See photos 3 and 4.
3. Fall tillage increases the risk of springtime “ponding.” See photo
5. Stubble knock-down not only causes variable snow accumulation across the landscape, but cultivation also tends to seal the soil by destroying ground pores that soak up runoff — the “tilth.”
TALLER STUBB LE, LESS MATTING
Zero tillage is good for snow trap and moisture retention. We know that. But how do we seed through this bulk?
It’s true, heavy layers of chaff and straw are real barriers for no-till if all that nice residue drags and clumps beneath a drill. Even if well distributed, the thick mulch may keep the soil wet and cold, hampering early spring planting. I am an advocate for novel harvest methods that mitigate these concerns.
The goal is to have the majority
In 2009 near Mannville, Alta., snow accumulation in fields of three-foot tall stripped stubble measured two to three times more than in 10-inch swathed stubble.
of crop residues remain intact and standing rather than processed and dropped behind the combine, thereby generating sustainable conditions more conducive for timely seeding. For example, a well designed straight-cut draper header can effectively minimize the amount of combine mulch or “surface trash.” With less mulch on the soil surface, your drill can more easily pass through it, over it and under it to seed into the firm undisturbed soil beneath. Playing with residue when you could be seeding is simply frustrating!
Keeping this in mind, here are two more no-till questions that still need answers:
1. Is crop residue trash or recycled nutrients? An agronomist understands the latter, but a machinery engineer’s perspective is essential to optimize the outcome. Normally “trash” refers to unwanted junk or scraps to throw away. Headache may be the term often synonymous with harvest, especially when straw is tough or lodged, nevertheless where will renewed organic matter come from?
2. How do we spread residue with Class 9 combines and their 36-foot and wider headers? A stripper-header is certainly one approach.
After decades of discovering mechanized ways to seed and fertilize directly into heavy residue (concluding there is actually no good reason for major tillage), I trust that better equipment will also eventually enable growers to surmount the harvest bottleneck created by an abundance of residue as a result of higher-yielding DS crops. Leaving more stubble standing is one answer. Seeding into this matt of tall stubble may indeed come down to precision guidance tools and technology for seeding between the rows.
STRIPPER DIARY, JUNE ENTRY
Trudging through those fields of tall stubble to measure snow-trap in March and revisiting through April thaw, my enthusiasm grew. It peaked even more by June as I observed crop after crop emerging similar or superior to nearby fields, despite the discouraging spring and the almost ridiculous amount of stubble. My thoughts soared: Could this be the missing piece of the puzzle I’ve been looking for?
Ron Heller is an agronomist, formerly with Alberta’s Reduced Tillage Linkages. He farms near Vermilion.