Cover crops, quick-growing crops, such as winter rye or clover, are planted between periods of regular crop production to prevent soil erosion and provide humus or nitrogen.
Check out these photos from Minnesota farmer Ray Rauenhorst on how he prevents water and wind erosion using cover crops:
Water spilling over into drainage ditch after a heavy/fast 3" rain. The topography is quite flat. The soil is heavy and black where farmers say, "My soil doesn't have an erosion problem."
A ditch bank about 8 miles from picture #1. The bank has caved in and is on its way to the Gulf of Mexico via the Maple, Le Sueur, Blue Earth, Minnesota, and Mississippi River system. These hills are conventionally tilled and have little residue to stop water erosion. This cave-in of sediment is also very costly for the county to remove as it now acts as a dam to restrict normal water flow.
After heavy rains on lighter, sandy soil, what didn't wash away the previous day is now blowing away. This field is also conventionally tilled. That's a farm building site in the distance.
This is another picture of the same field.
A graphic comparison of what can be done to prevent erosion. On the left is a strip-till field with rye cover that has been planted to soybeans. On the right is a field where conventional tillage is practiced. Note the line of demarcation - to the foot - literally!
The day after the wind went down. This wind erosion is from a high organic matter peat field. It also looked like the Sahara Desert the day before.
This is looking down from the combine while harvesting corn on October 30. The rye was aerially seeded about September 7.
Rye that was aerial seeded into standing corn - a very uniform stand.
Rye that was fall seeded into standing corn during the first week of September. The rye greens up very early in the spring. It also needs very few heat units to germinate and grow in the fall. About 34 degrees will get it going.
A very dense stand of rye on April 23. It should be burned down with Roundup® at this stage.
A close-up of the picture above.
This is a picture of a rye check strip with a waterway in the strip. The rye has been burned down and the field has been no-tilled into soybeans. With all the rye biomass along with the no-till, this field is no longer vulnerable to water or wind erosion. By the time the rye residue has decomposed on the surface, the soybean crop has already produced a canopy to further protect the soil - plus the dense root structure of the rye crop remains in the soil. Contrast this with the clean tilled field in the foreground.
The tenacity of rye. This rye has been aerially seeded into this drilled soybean field only 5-6 weeks earlier. With all the foliage on the soybeans at this date, it's almost dark below the soybean foliage, yet the rye thrives.
Fall rye that was strip-tilled in the fall. The planter had DAWN® row cleaners on to clear the path for the row of corn. Again, this field is not going to erode with either the wind nor the water. The track between the rows has been made by spring sidedressing of 28% nitrogen solution.
To my amazement, a duck also seemed to like the cover crop by building her nest between the corn rows.
A strip tilled corn field. This field went through a 5" rain in 1 hour and did not wash. This is also a hilly field that is subject to erosion in a clean tillage environment. Now with a hard 2" rain, I'm more apt to retain a net 2" of moisture all over the field versus before with nothing on the tops or sides of the hill and 4" on the bottom.
A very simple soybean practice. Harvest the corn in the fall. Next, plant the soybeans the next spring with no attachments on the planter. During my 6 years of tillage studies in the Monsanto Center of Excellence program, the 30' no-tilled soybeans were consistently the most profitable.
This rye strip was burned down too late with Roundup® in the spring. The rye has already crowded out the corn.
This is fall aerially seeded rye that was subsequent fall strip tilled. At this stage, the rye is just on the verge of precluding a successful stand of corn. The stage of growth and burndown of the rye is critical for the corn in the spring. This photo shows the rye just short of "sodding over."
Mark Zumwinkle, Soil Scientist/ResearcherMark.Zumwinkle@state.mn.us651-201-6240Ag Marketing & Development Division
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, firstname.lastname@example.org