Sept. 9, 2013 – Thirty per cent soil cover can go a long way in protecting the soil from erosion, notes OMAF in its latest Ontario Field Crop Report. Here are this week's recommendations on tillage and cropping.
Maintain 30 per cent soil cover all year long
Keeping the soil protected throughout the year is easy. Leave enough residue on the soil in the spring so there is at least 30 per cent residue cover left after planting. It's not a lot, but it can go a long way in protecting the soil from wind and water erosion. As that residue breaks down, the crop fills in to provide the cover through the season. After the crop is harvested, leave the residue untouched, minimize tillage to leave residue on the surface, or plant a cover crop to provide soil cover through the fall, winter and into the spring. The soil cover provides more benefits than soil erosion protection. The residue provides food for earthworms and other soil life, conserves soil moisture, improves soil structure and can help maintain or increase organic matter. Good soil structure allows more water to infiltrate into the soil. All of which can lead to improved yields.
Every tillage pass breaks down soil structure and aggregates.
Good soil structure is important for water movement into the soil. The more water that goes into the soil, less runs off and is lost. Well-structured soil allows more air in the soil to support root growth and soil life.
The tillage system must be economical when it comes to tillage and whoever makes the least passes wins.
Fewer passes leave more residue on the soil surface to protect from erosion, and also saves labour and fuel. Design your tillage system to keep soil out of surface water. Avoid excessive tillage. In many cases, tillage does not pay for itself in additional yield.
The tillage system should be sustainable in the long term.
Depleting organic matter levels and allowing the soil to erode is not sustainable.
Let the planter or drill do a tillage pass.
Adding coulters to the planter or drill can save a tillage pass, or eliminate the need for tillage all together. Trash whippers can remove residue from the row, reducing one or more tillage passes. Utilize a wide range of planter attachments to ensure good seed-to-soil contact.
Longer crop rotations are better.
Including a wide variety of crops will help increase organic matter levels, reduce pest problems and increase crop yields.
Include cover crops as much as possible.
Cover crops can provide a wide variety of benefits, such as soil cover to protect against erosion, adding organic matter and improving soil structure.
Manage residues at harvest.
Proper spreading of crop residues at harvest can reduce the need for tillage and avoid uneven soil drying in the spring.
No-tilling winter wheat into soybean or edible bean residue is the most profitable system, and provides the most soil cover.
Soybean residue not going into wheat
If the residue is spread evenly no tillage is likely needed. Coulter tillage or light secondary tillage may even out soil drying if residue is not evenly spread. Primary tillage of soybean residue generally provides no benefit.
No-tilling soybeans into corn residue is the most profitable system, and provides the most soil cover.
Reduced tillage and good residue management produces yields equivalent to moldboard plowing. This often costs less and provides more than 30 per cent soil cover. No-tilling corn after corn results in lower corn yields, even though it provides the most soil cover. Many growers successfully no-till corn after soybeans and cereal crops, protecting the soil from erosion.