Pinning hopes on new plant

Devine, a researcher at the agency8217;s Sustainable Agricultural Systems Lab, hopes farmers will replace much of their synthetic fertilisers, chicken pellets and cow manure with his variety of vetch, which he calls Purple Bounty. Some who have tried it think it has potential. 8220;It could be really helpful, in that it will give us more flexibility,8221; said Nick Maravell, who raises corn, barley, soybeans and hay on a 170-acre organic farm.

Crop rotation8212;a practice that goes back to Roman times8212;works in part because plants such as wheat, oats and barley are hardier when grown in soil where other plants have left nitrogen. Hairy vetch is a part of that cycle, using bacteria that pull nitrogen from the air for the plant8217;s own use during its winter and spring growing season. When the plant dies in May or June, the nitrogen stays in the soil, enriching it for crops such as corn, tomatoes and pumpkins.

After nine years of cross-breeding, Devine said he has developed seeds with the right characteristics for a superior vetch: It will survive as far north as upstate New York and flower at a more opportune time than current varieties. Devine also designed it to be plowed into the soil to make for more abundant harvests of corn, tomatoes and pumpkins.

Ideally, farmers will plant Purple Bounty, like other varieties of cover crops, in the fall. They8217;ll harvest the stalks when the plant flowers in May and let it lie in the fields, becoming a mat of dead material that prevents erosion. The ground cover can also cut back on weed growth, hold needed moisture in the soil and reduce the need for fertiliser.

Hairy vetch has long been a favourite among organic farmers, but the improved variety could increase the market for it among conventional farmers and enhance its reputation among some organic growers. The price of nitrogen-based fertilisers also has almost tripled in the past three years, making vetch a more appealing option for conventional farmers, he said. Nitrogen fertilisers cost about 50 cents per pound, so using vetch on a crop like corn would save about

25 per acre.

Vetch is at its best as a soil treatment after it flowers, so late flowering can delay spring planting and cut back on harvests, experts say. To come up with his variety of vetch, Devine ordered seeds from the US National Plant Germplasm System, a national repository. From the plants they produced, he selected the hardiest samples that grew over nine winters at an ARS tract in Keedysville, in the Maryland foothills south of Hagerstown. 8220;That way, you8217;re selecting under natural circumstances and getting something that8217;s survived the vicissitudes of winter,8221; Devine said.
-Dennis O8217;Brien LAT-WP