Narrow rows, early seeding, and heavier seeding rates are just some of the strategies organic farmer Ian Cushon uses to fight weeds on his 3,600-acre organic farm on the fringes of the black soil zone near Oxbow, Sask.
“In terms of weed management and crop competition, seeding equipment I think is the most important equipment on the farm,” Cushon said in a presentation at Ag Days.
“If you don’t do a good job of seeding, you’re at a disadvantage right from the start.”
Narrow row spacing with his Flexcoil 5000 air drill helps shade out empty gaps between the rows, and early seeding in late April and early May lets him put the seed into moisture before the top few inches dry out.
His triple-tanked seeding rig, with nine-inch shovels on 7.2-inch spacing and 3.5- inch steel packers on behind, is also set up to broadcast clover seed out the front at the same time as other crops go in the ground.
“Since we got this three years ago, we’ve seen a marked improvement in our crops,” he said.
Cushon tries to maximize natural fertility by using legume-heavy rotations, green manures and Jumpstart seed inoculant to pick up more phosphorus for the growing crop.
Choosing only the best, largest seed in any lot is another strategy.
“That’s an important strategy for getting an early establishing plant that is really competitive,” he said. “I take out about 25 per cent of my wheat to get the best, plumpest kernels.”
His rotation starts with a green manure fallow of heavy-biomass-producing Trapper peas or Indian Head lentils, followed by a cereal crop to soak up the nitrogen produced, and then a pulse crop such as lentils to restore fertility.
If the rotation is likely to stay clean of annual and perennial weeds, he often sows flax in year four on the pulse stubble. Seeding is often delayed, after a few harrow passes to catch the first flushes of weeds, he added.
“We often underseed our flax with alfalfa, and that leads us into the alfalfa part of our rotation,” he said, adding it is often harvested for seed in year two or three, then plowed down to fertilize higher value, but N-hungry crops such as hemp.
Green manure fallow costs about $80 per acre in year one, but wheat the following year typically yields 30 bushels to the acre. At about $12 per bushel, that pays $360 an acre, minus $226 in fixed and variable costs including the fallow year, leaving a net return of $134.
For oats, 70 bushels an acre is common on good green manure fallow and at $4 per bushel generates $280 an acre in gross revenue and about $50 in profit.
Flax on stubble often yields 10 bushels per acre and pays around $25 per bushel. Costs are lower for the stubble crop, and net returns are around $106/acre.
Peas net about $103 per acre after costs, and lentils (at $30 per bushel) pay about $142 per acre.
In a back-of-the-envelope calculation of the profitability of a 1,920-acre organic farm running one-third fallow, one-third stubble, and one-third green manure, Cushon said that a net profit of $158,000 per year, before factoring in labour costs, is possible.
That’s the good news about organic farming, he said. The bad news is that weeds, fertility and moisture are all limiting factors, and one year is never the same as the next.
Phosphorus depletion is an ongoing issue, he added, and adding more livestock in organic systems and using soft rock phosphorus as an amendment could offer solutions. Tillage requires caution, especially on vulnerable soils. But green manures and cover crops (where growing season length permits) helps to keep soil at home. Increased labour requirements and price volatility are also headaches, just as in conventional farming.
But the fact that nitrogen fertilizer accounts for 50 per cent of the energy used in Prairie agriculture gives organic farmers a good head start, he said.
“I think we’re less susceptible to energy and input price increases, although we’re still using lots of diesel,” said Cushon.
The grain, fibre and meat that leaves a farm represents an “export” of nutrients, and so Cushon expects to see more livestock being used to intensively graze green manure crops, as well as chaff pile and stubble grazing.
“In my thinking, the current agricultural systems are fragile and vulnerable because of declining fossil energy resources,” he said. “We’ve seen what high fuel prices can do to economies around the world. It’s going to have a huge impact as we find out how expensive it can be.”
daniel. [email protected]
agriculturalsystems arefragileand vulnerablebecause ofdecliningfossil energyresources.”
– IAN CUSHON