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Not Planting a Fall Garden?

Save your soil with a cover crop

A winter cover crop like rye will prevent soil erosion while sucking excess nutrients from your soil. It also helps keep weeds from getting a foothold in your garden.

If you are not planning a fall vegetable garden, it’s worth your while to consider a cover crop of rye or winter wheat. Your corn, beans, tomatoes, lettuce and pepper plants may not have used all of the nutrients in the soil. Even if you did not apply more fertilizer than the plants needed, even if you are an organic grower, there is organic matter in the soil that continues to decompose, releasing nutrients until the ground freezes.
    Unless these nutrients are absorbed by the roots of plants, they will leach deeper into the soil and enter the water table. Barren soil also is subject to erosion by wind and water. Unless you plant a cover crop, as farmers are required to do, you will be contributing to the Bay’s pollution.
    Cover crops that are planted immediately after a crop has been harvested absorb those excess nutrients, growing to cover the soil and protecting it from erosion. When the cover crop is plowed or rototilled under in the spring, it adds organic matter back into the soil. Upon decomposing, that organic matter will release nutrients for next year’s crop. The incorporation of organic matter in the soil improves both its physical and chemical properties.
    Allowing weeds to grow as a cover crop has the same effect as planting rye or wheat. However, weeds produce thousands of seeds that can persist in the soil for many years, so you will be compounding next year’s weed problem. Cover crops of rye or wheat are incorporated in the spring before they form seeds. These vigorously growing cover crops crowd out less vigorous weeds, thus reducing your weed problem.
    Some gardeners have complained that they have difficulty incorporating the cover crop in the spring. The solution is to mow the cover crop a week or so before you rototill the garden.
    If you don’t want to plant a cover crop and don’t want weeds, cover your garden with three or four inches of leaves. Using your rototiller, lightly incorporate the leaves in the surface layer of the soil. The leaves will slowly decompose, leaving a layer of organic matter that is resistant to erosion. In the process of decomposing, the microorganisms responsible for the decomposition of organic matter will absorb the excess nutrients in the soil.

Ask Dr. Gouin your questions at frgouin@erols.com. All questions will appear in Bay Weekly. Please include your name and address.