Erosion Control

Cover Crops: Making a Comeback

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Janice Kasperson - Erosion Control Editor
Although the practice of using cover crops on agricultural fields after a harvest is thousands of years old, it’s been largely displaced by modern chemistry. Cover crops were common in ancient China, India, Rome, and northern Europe. They were once used in North America—and still are, or are being used once again, in specialized areas like some California vineyards. But for the most part they were replaced decades ago by synthetic fertilizers, which provide nutrients with less effort. Why plant something that doesn’t bring in cash, after all?

Although the practice of using cover crops on agricultural fields after a harvest is thousands of years old, it’s been largely displaced by modern chemistry. Cover crops were common in ancient China, India, Rome, and northern Europe. They were once used in North America—and still are, or are being used once again, in specialized areas like some California vineyards. But for the most part they were replaced decades ago by synthetic fertilizers, which provide nutrients with less effort. Why plant something that doesn’t bring in cash, after all? [text_ad] Now cover crops are gaining in popularity with many US farmers because of benefits applied fertilizers can’t provide. These have to do with the general health of the soil—less erosion, greater fertility, fewer weeds. Cover crops add carbon and help maintain the organic elements of the soil—bacteria, fungus, and microbes. In some cases farmers find they have fewer pests to deal with and can use less water once cover crops have improved their soil, a process that can take a few years. This article from the New York Times visits a few farms that have revived the practice. Some cite increased crop yields from land that has had cover crops compared to land that has not. Others describe how plants like hairy vetch, cereal rye, or Oregon ryegrass help prevent soil compaction, aerate the soil, and thus trap nutrients instead of letting them wash away. Upon discovering the webbed root system left by Oregon ryegrass, says one Indiana farmer, “I thought to myself, I have been pulling the guts out of my tractor to remove compaction 14 inches deep with a ripper, and this plant has just bored a system of micropores four feet deep between cash crops all on its own.” The federal government has endorsed use of cover crops and offers small subsidies to farmers who adopt the practice. It can also eventually pay for itself. One family interviewed for the article says it spends an extra $100,000 a year for cover crop seed for the majority of its 6,200 acres. But it saves about $57,000 in fertilizer costs, and the larger crop yield also brings in about $107,000 in additional income. Factoring in other advantages like reduced erosion of topsoil, the family figures it gets $244,000 in yearly benefit from using cover crops. People are unlikely to make such a big change if they’re unsure of the benefits, though. Although the Natural Resources Conservation Service says cover crops are becoming more popular, as of 2012—the date of the last Census of Agriculture report—just over 10 million of the country’s 390 million acres of farmland were being planted with cover crops. In surveys the agency has conducted since, more farmers says they’re adopting the practice; the 2017 census will provide a more comprehensive picture. In the meantime private companies are also funding research on the effects of cover crops, including supporting the Soil Health Partnership, a National Corn Growers Association research project. EC_bug_web

Now cover crops are gaining in popularity with many US farmers because of benefits applied fertilizers can’t provide. These have to do with the general health of the soil—less erosion, greater fertility, fewer weeds. Cover crops add carbon and help maintain the organic elements of the soil—bacteria, fungus, and microbes. In some cases farmers find they have fewer pests to deal with and can use less water once cover crops have improved their soil, a process that can take a few years.

This article from the New York Times visits a few farms that have revived the practice. Some cite increased crop yields from land that has had cover crops compared to land that has not. Others describe how plants like hairy vetch, cereal rye, or Oregon ryegrass help prevent soil compaction, aerate the soil, and thus trap nutrients instead of letting them wash away. Upon discovering the webbed root system left by Oregon ryegrass, says one Indiana farmer, “I thought to myself, I have been pulling the guts out of my tractor to remove compaction 14 inches deep with a ripper, and this plant has just bored a system of micropores four feet deep between cash crops all on its own.”

The federal government has endorsed use of cover crops and offers small subsidies to farmers who adopt the practice. It can also eventually pay for itself. One family interviewed for the article says it spends an extra $100,000 a year for cover crop seed for the majority of its 6,200 acres. But it saves about $57,000 in fertilizer costs, and the larger crop yield also brings in about $107,000 in additional income. Factoring in other advantages like reduced erosion of topsoil, the family figures it gets $244,000 in yearly benefit from using cover crops.

People are unlikely to make such a big change if they’re unsure of the benefits, though. Although the Natural Resources Conservation Service says cover crops are becoming more popular, as of 2012—the date of the last Census of Agriculture report—just over 10 million of the country’s 390 million acres of farmland were being planted with cover crops. In surveys the agency has conducted since, more farmers says they’re adopting the practice; the 2017 census will provide a more comprehensive picture.

In the meantime private companies are also funding research on the effects of cover crops, including supporting the Soil Health Partnership, a National Corn Growers Association research project. EC_bug_web

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Comments

  1. I’ve been experimenting with use of cover crops, such as tillage radish, in reclamation seeding of native species, particularly in areas with compacted soils where mechanical tillage is difficult or not possible. I would be interested in learning if others are also experimenting with cover crops for reclamation of disturbed lands.

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