Author
 |
Williams, John |
|
Wilkins, Dale |
|
Douglas Jr, Clyde |
|
Rickman, Ronald |
|
Submitted to: Soil & Tillage Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/25/2000 Publication Date: N/A Citation: N/A Interpretive Summary: Soil loss from dryland farms on the Columbia Plateau results primarily from rain falling on frozen, cultivated soil. Soils are most susceptible to erosion when farmed in a traditional manner using a moldboard plow, summer-fallow, multiple secondary tillage passes, and fall planted to winter wheat. These practices help control weed and disease infestations. Unfortunately, they also destroy soil structure and lead to soil loss by water erosion. Conservation-tillage#practices have not been widely accepted because of associated weed and disease problems. A new conservation tillage and crop residue management system, the mow-plow system, has shown promise for weed control. This system incorporates traditional and new innovations wherein standing crop residue is cut and distributed onto a plowed surface, and only requires a single pass of the equipment. Using simulated rainfall, we compared water runoff and soil erosion in the mow-plow system to moldboard plow and chisel plow winter- wheat/summer-fallow systems. Water runoff was not significantly different among treatments. The chisel plow treatment provided the best protection against soil erosion, followed closely by the mow-plow (high residue) treatment. The moldboard plow treatment was the least effective treatment for erosion control. The erosion response from the mow-plow (low residue) treatment was highly variable and not statistically different from the moldboard plow treatment. These results demonstrate the importance of maintaining cover on the soil surface. The mow-plow system, where adequate straw residue is available, is superior to moldboard plow system for soil conservation. Technical Abstract: Soil loss from dryland farms on the Columbia Plateau results primarily from rain falling on frozen, cultivated soil. Soils are most susceptible to erosion when moldboard plowed, summer#fallowed, repeatedly rod-weeded or cultivated, and fall planted to winter wheat. These practices help control weed and disease infestations. Unfortunately, they also destroy soil structure and lead to soil loss by water erosion. Conservation tillage practices have not been widely accepted because of associated weed and disease problems. A new conservation system using crop residue management, the mow-plow system, has shown promise for weed control. The moldboard plow is the primary tillage tool, but standing crop residue is cut ahead of the plow and distributed onto the adjacent plowed surface. This system requires a single pass of the equipment. We compared runoff and erosion in two levels of residue application in the mow-plow system to moldboard plow and chisel plow winter#wheat/summer-fallow systems. We simulated rainfall onto frozen soil during natural thawing conditions and collected runoff to evaluate water and soil loss. Runoff was not significantly different among treatments. The chisel plow treatment provided the best protection against soil erosion, followed closely by the mow-plow (high residue) treatment. The moldboard plow treatment was the least effective treatment for erosion control. The erosion response from the mow-plow (low residue) treatment was highly variable and not statistically different from the moldboard plow treatment. These results demonstrate the importance of maintaining cover on the soil surface. The mow-plow system, where adequate straw residue is available, is superior to moldboard plow system for soil conservation |
