I’ve been discussing in the past several articles important tips for continuous no-till crop production on dryland and irrigated acres. Managing residue begins at harvest with even distribution of the residues at harvest.
I’m a big fan of using stripper headers in harvesting small grains like winter wheat, as it leaves residues in place and attached to the soil surface. The entire plant is left undisturbed for maximum residue height. You’re not cutting the residue in half and expecting the combine to handle and distribute the residue evenly out the back of the combine. This makes for much more even residue distribution if you simply leave the residue in place.
A chaff spreader is also an essential piece of the combine. Distributing the chaff evenly out the back of the combine will make planting the following crop much less difficult.
On our irrigated acres we have looked at crop rotation and grazing livestock to help with residue management.
The crop rotation we’ve designed for our farm consists of winter wheat; a forage crop planted following winter wheat and grazed in the winter; dry edible beans planted the following spring; corn the next spring that is grazed in the winter following corn harvest; field peas the following spring, and back to winter wheat in the fall.
This rotation has many agronomic benefits and allows us to manage the high-residue crops of winter wheat and corn with the use of forages for grazing and livestock. Following the winter wheat we plant a mixture of mostly cool-season crops that will grow late into the fall.
The mixture we’re using consists of oats, turnips, radish, fava beans and flax. The oats are grown to add carbon to the system and tonnage to the forage. The turnips and radish are added for their grazing benefit.
The brassicas, consisting of the turnips and radishes, also help break down the winter wheat stubble. I don’t know why, but brassicas have been shown to really break down residue.
The fava beans are added to produce nitrogen. I’ve never used fava beans before, but from what I understand they fix nitrogen at a higher rate than even a field pea. My understanding is fava beans also carry very little disease that may interfere with our edible bean production the following growing season.
Flax is added to replace the vertical structure lost when drilling the forage crop. The flax produces a tall, sturdy stem, which will catch snow during the winter prior to grazing. We may add additional forages to this mix prior to seeding as I discuss this mixture with our seed suppliers and other producers.
Planting these forages will increase the amount of time we have living plants and roots growing on our field. This will add additional carbon into our soil, which will increase the organic-matter content of the soil. The diverse forage crop will also increase the diversity and populations of our soil micro-organisms. This will improve the health of our soil.
The grazing of the forages helps us manage the winter wheat residues and improves the health of the soil. We also have the economic benefit of grazing the livestock on our farm.
Following the forages with edible beans the following growing season allows us to plant our corn the next spring in the lower residue edible bean stubble. This allows our corn to get off to a quicker start with fewer residues than our old rotation of following winter wheat with our corn.
We use livestock to help manage corn residues by grazing the corn residues prior to seeding our field pea crop in the spring.
The crop rotation we use along with the forages and livestock for grazing help us manage residues on our irrigated acres. I think this crop rotation also provides agronomic benefits to our farm along with bringing livestock into our operation. I think this rotation will work well on our continuous no-till irrigated crop production system.