SARE 1998 Highlights

Cover Crops, Strip Tillage Build Soil

Strip-till—working a narrow band of soil in between strips of residue—attracts beneficial insects, and, combined with cover crops, brings better yields. Photo by John Luna

A SARE project testing cover crops and new tillage regimes in Oregon has helped vegetable farmers improve crop yields, beat weeds, lower input costs and reduce agricultural runoff. Researchers worked with several growers in the Willamette Valley to fine-tune their use of cover crops. Legumes add nitrogen to the soil; grains capture excess nitrogen. The long-term project measures those environmental benefits plus profit potential against cover crop costs. Wet springs and a strict planting schedule dictated by vegetable processing companies pose challenges to growers trying to incorporate cover crops. Researchers sought a combination of covers that can fix nitrogen and add organic matter but be killed in early spring. A winter cover of oats, vetch and Austrian winter peas, followed by strip-tilling sweet corn, brought better yields. Strip-till—working a narrow band in between wider strips of residue-covered soil—helps address moisture concerns and enables farmers to prepare a seedbed in just one tractor pass. In three fields enrolled in those trials, the strip-tillage system returned $100 per acre more than the standard tillage system in increased yield and cost savings from reduced tillage. On one farm, tillage savings equalled about $30 per acre. Not tilling the ground also keeps habitat in place for beneficial insects, reducing the need for pesticides for growers trying to combat cutworm in corn. (SW94-29)

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