Cover Crops Build Soil

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 newtillage regimes in Oregon has helped vegetable farmers improvecrop yields, beat weeds, lower input costs and reduceagricultural runoff. Researchers worked with several growers inthe 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 plusprofit potential against cover crop costs. Wet springs and astrict planting schedule dictated by vegetable processingcompanies pose challenges to growers trying to incorporate covercrops. Researchers sought a combination of covers that can fixnitrogen and add organic matter but be killed in early spring. Awinter cover of oats, vetch and Austrian winter peas, followed bystrip-tilling sweet corn, brought better yields.Strip-till—working a narrow band in between wider strips ofresidue-covered soil—helps address moisture concerns andenables farmers to prepare a seedbed in just one tractor pass. Inthree fields enrolled in those trials, the strip-tillage systemreturned $100 per acre more than the standard tillage system inincreased yield and cost savings from reduced tillage. On onefarm, tillage savings equalled about $30 per acre. Not tillingthe ground also keeps habitat in place for beneficial insects,reducing the need for pesticides for growers trying to combatcutworm in corn. (SW94-29)

Top