ABSTRACT
Agrochemicals are group of chemical compounds used either to improve the production of crop or to manage pests and phytopathogen or plantgrowth hormones or soil conditioners. Even though their usage improves crop productivity, plant-protection, and soil quality for plant-growth; they can contaminate the environment. Accumulation of agrochemicals in soil not only affects soil and water but can also have negative impacts on air quality in the cultivated area. So, studying the fate and behavior of applied agrochemicals in soil and how its deleterious effect can be nullified in soil itself is very important.
Agrochemicals as fertilizers are mainly compounds of N, P, and K. pH adjusting agents like limestone (CaCO3) or dolomite (CaMg[CO3]2) are added to restore soil quality. To reduce the abundance of pests/insects, organophosphorus or chlorinated hydrocarbons are often used. In addition, animal husbandry products like antibiotics or growth hormones also accumulate in soil. The major impact of these non-biodegradable agrochemicals is on soil physicochemical and biological quality and deteriorates the soil. In addition, their leakage to larger water bodies can contaminate and result in eutrophication. The droplets if escape to air can be dispersed to larger areas and can cause air pollution. A major threat is yet to be addressed. Excessive usage can lead to their residue accumulation in crops leading to health hazards on consumption. Therefore, it is very important to nullify their effects while they are in soil itself. In order to avoid side effects and by product accumulation chemical degradation methods cannot be considered. 68Biodegradation method using microbial system is a well-studied and widely accepted technique.
Among the abundant microbial population of soil bacteria selection of specific strains of bacteria which can utilize these agrochemicals as their carbon or energy providers and electron donors is a crucial step. Identifying the inherent microbial enzymes capable of agrochemical degradation and enhancing its catalytic efficiency is the next crucial step. Role of environmental parameters on bacterial degradation efficiency also has to be thoroughly analyzed because slight variations from optimal conditions tend to increase the enzymatic degradative capacity. Nutrient limitations and addition of stress factors can also improve the biodegradation capacity of microbial population. Finally genetic manipulation can also be employed to improve the degradative capacity of selected bacterial species.
