What’s so great about cover crops? By planting between growing seasons, farmers can literally turn field negatives into field positives. Take a look at the multiple advantages learned from planting appropriate cover crops. (Source: Purdue University Department of Agronomy)
1. Water erosion control in sloping fields. Research has shown that fields with wintercover plowed under in the spring have 55 percent less water runoff and 50 percent less soil loss annually than do fields with no winter cover. More recent studies show soil losses from corn or soy- beans no-tilled into a vigorous growth of rye or wheat to be 90- 95 percent less than soil losses from corn and soybeans conventionally tilled.
2. Wind erosion control. In a given state, such as Indiana, millions of acres are susceptible to wind erosion. These acres primarily consist of coarse-textured soils (sands) and mucks along major rivers. A cover crop left on the surface to be no-till planted is tremendously effective in controlling wind erosion.
3. Improved soil tilth. The added tilth from a winter cover crop, whether turned under or left on the surface, benefits many types of soils, especially but those with less than 2.5 percent organic matter in the plow layer.
4. Improved crop yield. In recent experiments in the state of Kentucky, winter cover used with no-till planting markedly increased corn yield. For instance, three-year average continuous corn yields were 8 bushels per acre greater when planted into a winter cover of rye and 25 bushels per acre greater when planted into hairy vetch than yields from plots without winter cover. The significantly higher yield in the hairy vetch cover plots was due primarily to the extra nitrogen (N) that this legume provides. All plots in the experiments had received 88 pounds of fertilizer N.
Other advantages: Cover crops recycle nutrients that might otherwise be lost to leaching during the winter and spring. Also, cover crops used in no-till production of corn or soybeans provide an excellent surface mulch after being killed with a contact herbicide; the mulch not only reduces soil erosion, but also slows evaporation of soil moisture, increases infiltration of rainfall, increases soil organic matter and aids in control of annual weeds. Additionally, cover crops can often be grazed by ruminant animals in the early spring before row crops are planted.