Cover crops are an idea whose time has come.
In one sense, cover crops are a new practice. Several decades ago, the number of acres planted in cover crops in the U.S. was negligible; today it numbers somewhere north of 15 million and rising.
The use of the term dates to at least the late 1800s, though. Many early references to cover crops seem to be for use in orchards, rather than in row crops or vegetables.
Were cover crops — by some other term — being used prior to this? Farmers certainly were in the practice of growing non-cash crops to cover their soil and improve their fields. Many were rotating their plowed fields with short-term perennial pastures. In some places these were known as “herbal leys” (see Frank Newman Turner’s books, reprinted from the 1950s by Acres U.S.A.). Fields that for a few years had served as paddocks for horses, sheep and cattle — and thereby were naturally fertilized and the soil health improved (assuming proper livestock rotation) — were ploughed up in order to grow cash crops for a few years. “Cover crop” seeds were needed to replant the pastures, but only infrequently.
Perhaps we could say that cover crops exist today because these older farm management practices do not. When farms were smaller and more diversified — particularly when pretty much every farm integrated livestock in some way — cover crop seeds as we know them today weren’t really necessary.
This isn’t in any way a criticism of modern cover cropping techniques. They’re not a “second best” alternative. Growers today are able to take advantage of a wide array of different species of cover crops to address different needs, from soil erosion (perhaps the most popular use) to nitrogen fixation, increasing soil organic matter, weed suppression, compaction reduction, supplementing grazing or hay, attracting beneficial insects, nematode control and more. Cover crops are an incredible instrument in the toolbox for growers and grazers.
One reason cover crops weren’t widely used for row crops and vegetables until recently is that it’s difficult to efficiently harvest their seed in places where it rains when the seeds need to be harvested. This is an issue our forebears didn’t have the logistical pipeline to deal with — and thus their relatively simple rotation of pastures with cash crops. See the interview with Oregon’s Don Wirth in this issue, though, where he discusses some of the advantages he as a cover crop seed grower experiences by being in the Willamette Valley.
The articles in this issue by Loran Steinlage on relay cropping, by Anne and Eric Nordell on cover crops and nutrient excesses in hoophouses and by Steve Groff on nutrient density — along with an interview with Colorado farmer John Heermann — will hopefully inspire you to either take the first step into cover crops or to be even more bold in your use of them this fall or next spring.
And that’s the view from the country.
