Conservation tillage soil erosion

The use of conservation tillage, made possible by triazine and other herbicides, has dramatically reduced soil erosion and its on- and off-site impacts. Significant benefits from the use of herbicides such as the triazines can be realized because conservation tillage reduces erosion, sedimentation, and flooding. By creating a crop field with many features comparable to those in natural areas, conservation tillage also provides other benefits to the environment and to wildlife. 

Peters RD, Sturz AV, Carter MA, Sanderson JB (2003) Developing disease-suppressive soils through crop rotation and tillage management practices. Soil Till Res 72 181-192 Pfiffner L, Luka H (2003) Effects of low-input farming systems on carabids and epigeal spiders - a paired farm approach. Basic Appl Ecol 4 117-127 Pimentel D, Harvey C, Resosudarmo P, Sinclair K, Kurz D, McNair M, Crist S, Shpritz L, Fitton L, Saffouri R, Blair R (1995) Environmental and economic costs of soil erosion and conservation benefits. Science 267 1117-1123... 

Conservation agroecosystems developed in the Great Plains of the U.S. to control soil erosion are characterized by the presence of varying quantities of plant residues on the soil surface. This residue mulch protects the soil from the erosive forces of wind and water, resulting in improved stream water quality and soil conservation. Conservation tillage systems also help maintain soil productivity and reduce energy requirements of crop production (15). However, crop yield reduction has been observed with conservation wheat production in some areas of the U.S. (16-18) and with rice culture in the Far East (, 20). 

Conservation tillage and no-till often produce dramatic decreases in water runoff and increases in water infiltration, which results in a reduction not only in soil erosion, but also in pesticide and nutrient runoff into water (Glenn and Angle, 1987 Hall et al, 1991). In several studies of best management practices (BMPs), no-till was shown to reduce herbicide runoff by an average of 70%, while ridge till showed a 40% reduction (Figure 1.7). 

Because soil sediment has an extremely negative impact on streams, rivers, and lakes, erosion reductions credited to conservation tillage provide major benefits to aquatic ecosystems. Additionally, conservation tillage benefits wildlife by providing more crop residues for cover, more food sources (grain and weed seed left on the soil surface, as well as a greater number and variety of invertebrates), and less field disturbance. 

Seta, A.K., R.L. Blevins, W.W. Frye, and B.J. Barfield (1993). Reducing soil erosion and agricultural chemical losses with conservation tillage. J. Environ. Qual., 22 661-665. 

Efforts to decrease soil degradation and erosion have been demonstrated by the rapid adoption of conservation tillage and no-till by farmers within the United States as shown in Table 32.2. 

Soil sediment from erosion was found in the Big Raccoon Creek in Indiana in the early 1980s. Some dry spells in the 1980s improved the situation, due to lower sediment loads. Rainfall was much heavier in the 1990s. However, sediment erosion has decreased due to the adoption of conservation tillage. In 1989, about 10% of corn and soybean acreage was no-till. By 1997, 84% of soybean was no-till, and 41% of com was no-till or strip-till (Brunoehler,... 

Conservation tillage is one of the most practical and economical ways to reduce soil erosion. Surface crop residue protects the soil from the erosive impacts of wind and rain. Reductions in erosion are proportional to the soil coverage of crop residue. From 78% to 89% of the variance in erosion between tillage systems is explained by the percentage of soil coverage by plant residue (Laflen el al, 1978). No-till systems, which leave nearly all surface plant residue in place, usually reduce erosion by 90% or more. 

Pesticide Formulations for Use with Conservation Tillage (22). Rising fuel costs and the need to prevent soil erosion and to save soil water has spurred interest in conservation tillage techniques. These techniques often require special granular formulations capable of penetrating plant residue and preventing pesticide evaporation and UV attack while the granules remain on the soil surface. 

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