Temperature, moisture, soil type, microbial activity, oxygen concentration, sunlight, nitrification, and the amount of leaching all have an effect on the breakdown of pesticides in the soil (Extoxnet, 2000a). Rainfall patterns and the timing/intensity of irrigation in relation to high rainfall intensities will also influence herbicide movement in or from soil. Metolachlor is considered to be moderately persistent in different soil types (U.S. EPA, 1997), and has an average field dissipation half-life of 114 days (Kollman and Segawa, 2000). In relation to high rainfall intensities, the patterns, timing and intensity of irrigation will also have an influence on the herbicide movement in or from soil. Metolachlor has an average field dissipation half-life of 114 days and is considered to be present in a number of different soil types (Kollman and Segawa, 2000). Metolachlor is considered to moderately adsorb to soil. The adsorption of the pesticide increases with increased soil organic matter and clay content, and can slow its movement in soil. 12 Due to the fact that Metolachlor is considered to have a moderate absorbency rate in soil, the rate of absorption of the pesticide will be greater if an increase in clay content and soil organic matter is present; it can also slow the movement in soil.
This “chloroacetanilide herbicide first registered in the United States in 1976, is used for general weed control in many agricultural food and feed crops (mainly corn, soybeans and sorghum), turf and other residential applications”. In 1976, this herbicide was officially registered in the United States for the use of general weed control in many types of agriculture, specifically corn, soybeans and sorghum. When absorbed through the roots and shoots just above the seed of the target weeds, it acts as a growth inhibitor by suppressing synthesis of chlorophyll, proteins, fatty acids and lipids, isoprenoids (including gibberellins), and flavonoids (including...
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