Author
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Reeves, Donald |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 10/30/2003 Publication Date: 10/30/2003 Citation: Reeves, D.W. 2003. Conservation agriculture: Improving water quality. Meeting Abstract. Interpretive Summary: Technical Abstract: Conservation tillage maintains crop residues on the soil surface. These residues greatly impact water movement into soil, and the risk for run-off of sediment, agrochemicals, and nutrients to surface waters is lessened. Reducing run-off of sediments and the nutrients (primarily nitrogen and phosphorus) and agrochemicals bound to sediment improves water quality. It has been estimated that erosion losses go from 11 tons of soil/acre/year with conventional tillage to 2.9 tons/acre/year with conservation tillage. This is an 8.1 tons/acre/year savings of soil and associated chemicals that does not wind up in our waters. In the southeastern USA, in the last 4 years, over 1.3 million acres of cotton converted to conservation tillage. This saves nearly 11 million tons of soil worth $198 million in on and off-site impacts annually. Conservation tillage also reduces the need for irrigation and improves water-use efficiency of irrigated crops. Improved nutrient use by crops is the result. The nitrogen and phosphorus utilized by crops does not become an environmental problem in our waters. In some cases, increased infiltration with conservation tillage can increase the risk of nitrate leaching into ground waters, but the benefits of conservation tillage in reducing run-off far outweigh the risks from ground water contamination from increased infiltration. With conservation tillage, soil quality is improved and soil biological activity is increased. The increase in soil organic matter and associated microbial activity helps to degrade pesticides before they reach surface or ground waters. With riparian buffers and wise nutrient management, conservation tillage offers tremendous benefits to water quality and conservation. |
