No-till crops like wheat and peas can be grown without undue erosion on land that has been rested in grass under the federal Conservation Reserve Program (CRP), according to a 6-year study by Agricultural Research Service scientists.
CRP lands are often judged to be highly erodible. No-till planting minimizes erosion because crop seeds are planted directly through the plant residue left from the previous crop, without plowing the field.
Soil scientists Donald L. Tanaka, Stephen D. Merrill and colleagues at the ARS Northern Great Plains Research Laboratory in Mandan, N. D., began their study in 1994 on plots laid out on former wheat fields that had been seeded to a grass-alfalfa mixture under the CRP program in 1989.
In 2000, Merrill, Chi-hua Huang, a soil scientist with the ARS National Soil Erosion Research Lab in West Lafayette, Ind., and others twice repeated a 3-year rotation of spring wheat, winter wheat and dry pea for a total of six growing seasons.
First, they grew the crops under both no-till and moderate conventional disk tilling. Then they used rainfall simulation equipment to compare the soil erosion that occurred with each of those tillage methods, with erosion caused on plots left in grass and harvested for hay once a year.
The researchers found that growing the crops with no-till caused no more erosion than occurred when grass was harvested annually for hay.
They also showed that both the land cropped with a wheat-pea rotation under no-till and CRP grassland annually harvested for hay had one-sixth as much erosion as did land cropped with moderate conventional-tillage.
ARS is USDA's chief scientific research agency.