Simply Sustainable

	Jerry Van der Veen, a northwest Washington dairy farmer, has been growing relay crops of grass between his corn rows since 1996. Going Under Cover Cover Crops Reduce Erosion and Supply Nutrients to the Soil After corn harvest, Jerry Van der Veen’s soil lay naked, exposed to erosion from northwestern Washington’s heavy rainfall. He’d heard about “relay cropping” in Canada and decided to give it a whirl (FW95-100). The Mount Vernon dairy farmer plants corn in early May. At the six-leaf stage, he cultivates, band sprays and plants his relay crop of annual tetraploid ryegrass. Then he forgets about it till harvest. “When the corn comes off, there are more weeds and the grass looks like nothing,” says Van der Veen. “But pump a little manure, give it some sunshine and it grows like crazy.” The grass can be plowed down as a green manure or harvested as forage, sometimes providing two cuttings and allowing him to utilize the nutrients by recycling them through the cows. The Natural Resources Conservation Service is promoting the practice, adopted by at least two area producers. In the desert Southwest, Milt McGiffen, vegetable crops specialist with the University of California Riverside, tested cowpea, plowed down as a green manure or used as mulch in reduced tillage systems. The cover crop increases yields, requires little water, takes no fertilizer, produces biomass and nitrogen and reduces weeds and nematodes (SW98-044). “The Western SARE funding has certainly changed the way producers look at things,” says McGiffen. “The project has provided them with new tools that are being used on thousands of acres.” Vegetable growers in the desert Southwest are growing cowpeas as a cover crop for mulch or plowed down as green manure. In California’s San Joaquin Valley, producers lacked information and experience on cover crops. Jeff Mitchell, vegetable crops specialist at UC Davis, anticipated that cover crops could reduce rainfall runoff, increase water infiltration and scavenge residual nitrogen to reduce leaching in the valley’s intense cropping systems (SW97-045). Mitchell found that four cover crops—barley, vetch, phacelia and a barley-vetch mix—all decomposed rapidly during spring and summer, “providing new information on an important management option for carbon sequestration.” To promote the use of cover crops in the Pacific islands, Richard Bowen of the University of Hawaii coordinated a project that gathered information on 26 cover crops and green manures (EW98-012). Specialists from Hawaii, Guam and the Northern Marianas Islands conducted workshops with farmers and ag professionals, developed a Web site with plant descriptions, established 11 plots on six islands to demonstrate the crops and created a CD-ROM and a series of leaflets on tropical cover crops.   “A unique strength of Western SARE is its ‘grounded’ projects involving land managers/farmers asking the questions and helping to devise answers that work for their operation. This promotes stewardship with producers actively assuming responsibility for the land and the surrounding environment in a manner that respects the long-term ecology and community values while recognizing the need for economic vitality.” Sandy Halstead, agriculture initiative specialist, EPA Region 10 Office of Ecosystems and Communities, Prosser, Washington Simply Sustainable Home Top