Cover crops related work of Mark Zumwinkle and Adam Herges at the
Minnesota Department of Agriculture

The environmental benefits of cover crops are well documented. However, there is a surprising lack of cover crop acreage on the Minnesota landscape. This is primarily due to the high cost of establishment. There is also a narrow window of opportunities in MN for cover crops establishment.  To overcome these obstacles, the Minnesota Department of Agriculture is working with creative farmers to find ways to fit cover crops into Minnesota farming systems and increase cover crop acres in Minnesota. We have found ways to make this happen by encouraging farmers to establish cover crops after canning crops, drilling after silage, aerially seeding into row crops, and adding to fresh market vegetables and organic systems.

Farmers can gain economic returns and benefits by grazing cover crops and harvesting the cover crop as green chop. Other associated benefits include using the cover crop ground as a manure disposal site, improvements in soil quality and soil organic matter.

Mark Zumwinkle and Adam Herges are working on improving the dependability of aerial seeding (or overseeding). They are cooperating with southeast Minnesota farmers to seed a winter rye cover crop in standing field corn, silage corn, sweet corn, and soybeans using a helicopter. Rye planted in late October or early November results in unreliable regrowth the following spring. In contrast, rye seeded in late summer germinates in the understory of the cash crop and produces a strong stand when the cash crop is removed. The helicopter is able to negotiate variable terrain and seed relatively small acreages.

For more information on aerial seeding please check out the Arieal seeding winter rye brochure and a Presentation on winter rye aerial seeding into corn and soybeans (a project with Minnesota farmers Andy Hart and Ray Rauenhorst).

Rye emerging in soybeans in the first week of September.
Photo by Mark Zumwinkle.

Rye emerging in harvested sweetcorn.
Photo by Mark Zumwinkle

Rye growing in early winter. Photo by Mark Zumwinkle

Cows grazing on rye cover crop in the last week of April.  This reduces pressure on the permanent pasture.  Notice overgrazed permanent pasture in foreground. 
Photo by Mark Zumwinkle.

The team is supporting Minnesota animal agriculture by providing alternative forage. They are also working towards creating a state-wide cover crop program. Future plans include exploring potential synergy between cover crops, manure, conservation tillage, and organic systems. Their plans for the next year include documenting the environmental benefits of cover crops on the landscape using field edge monitoring and rainfall simulations. They have created ongoing dynamic working groups highlighting farmer creativity and networking with University researchers. Their goals are to increase farmer participation, develop new farming systems, and cover crop testing sites for farmer use.

For information about how cover crops can be a tool to fight against soil erosion read the brochure Are you covered? (Stop soil erosion on canning and row crop acres) by Mark Zumwinkle.

Ray Rauenhorst's (farmer) prevents water and wind erosion by using cover crops. Here are some of his photos:

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!

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."

A very dense stand of rye on 4-23-02.  It should be burned down with Round Up at this stage.

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.

Check out the rest of Ray Rauenhorst's photos on how he prevents water and wind erosion with using cover crops by clicking here

Additional links

Mark Zumwinkle's work on Living mulch: Living Mulch Literature Review Living Mulch of Alfalfa for Specialty Crop Production

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