No-till crops put down roots in high-cost commodity market

No-till agriculture has been touted as the wave of the future for several years, praised for its ability to repair marginal land, reduce the need for nitrogen and soak up carbon dioxide. Now, more and more farmers are turning to annual rye grass as the no-till crop of choice, particularly for crops associated with biofuels, such as corn and soy beans. Dan Towery, agronomist and 25-year veteran of the Natural Resource Conservation Service, says growing annual rye grass over corn fields in a no-till environment can save farmers $40 to $50 per acre in nitrogen costs alone.

Annual rye grass has a root structure that reaches deeper into the soil than many other crops, allowing the plant to tap into nutrients far below the surface. The cover crop is planted in August or September, after the harvest, grows through the winter and is killed off in April or May. One to two weeks later, when farmers plant their next crop, it access those nutrients more readily. Towery calls it "nutrient mining," and says it saves farmers additional money by reducing the need for fertilizers such as phosphorus. Although the most common way to kill off cover crops in a no-till environment is to employ herbicide, Towery says without taking out the cover crop, it could compete for nutrients and moisture with the cash crop, and if left alone the cover crop could reseed, which would not be productive.

For soybean farmers in particular, an annual rye grass cover crop can actually increase production, which more directly puts money in farmers' pockets. Annual rye grass is considered a natural antidote to “soybean cyst nematode," a persistent pest that is difficult to kill. Towery says there's anecdotal evidence that multibillion dollar annual losses due to the pest can be turned around quickly with annual rye grass. "The farmers are realizing an 8 to 10 bushels per acre increase of beans which, at $12 per bushel, means more than $100 more per acre," he says. "With a $25,000 investment in annual rye grass for 1,000 acres, the increase of $100,000 more than pays for the up-front cost."

Although some farmers can increase profits through the use of annual rye grass, Towery is conservative in his estimates on the whole. He asserts that the monetary savings will balance out with the cost of planting, but that the crop brings non-monetary benefits as well, such as improved soil quality, increased access to moisture and nutrients, and the potential for use of the crop as forage or hay for livestock.

Tim Buckley, a spokesman for the Oregon Ryegrass Growers Seed Commission, is also optimistic, but cautious not to oversell no-till or cover crops, fearing that farmers who don't have immediate results may give up entirely. "When farmers move to no-till for the first few years, production in crops can fall off, largely because they’re not stirring up and oxidizing what’s left and it takes the soil a while to stabilize," he explains. "During that time, they might continue adding fertilizer as in the past, but annual ryegrass can reduce the time for that transition by half, thus once the cover crop has been in place in a no-till regime for two or three years, production will increase rapidly as organic matter, earth worm count, nutrient mining, better infiltration of water to deeper layers, and soil chemistry improves."

Annual rye grass is currently being evaluated as part of a multi-million-dollar carbon sequestration study currently being conducted by the U.S. Department of Energy. In addition to evaluating various ways to trap carbon underground, the department is investigating the sequestration of carbon through the use of more planted crops and forestlands.