Factors controlling degradation of pesticides in the soil environment: A Review - TI Journals

Abstract: Once a pesticide is introduced into the environment, whether through an application a disposal or a spill, it is influenced by many processes. These processes determine a pesticide’s persistence and movement. Today’s concern is movement of pesticides to groundwater. An understanding of the fate processes can help every pesticide applicator ensure that applications are not only effective but also environmentally safe. Microbial degradation is the breakdown of pesticides by fungi, bacteria, and other microorganisms that use pesticides as a food source. Most microbial degradation of pesticides occurs in the soil. Soil conditions such as moisture, temperature, aeration, pH and the amount of organic matter affect the rate of microbial degradation because of their direct influence on microbial growth and activity. The frequency of pesticide application also is a factor that can influence microbial degradation. Rapid microbial degradation is more likely when the same pesticide is used repeatedly in a field. This paper reviews what is known of the influence of the physical and chemical characteristics of the soil system, such as moisture content, organic matter and clay type, nutrients, temperature, salinity and pH on the sorption, desorption, degradation and biodegradation of pesticides. An understanding of the fate of pesticides is essential for rational decision-taking regarding their authorization.