Chemical pesticides are toxic those substances that are used for killing the living things, which includes herbicides, insecticides, fungicides, rodenticides and others. The use of toxic pesticides to manage pest problems has become a common practice around the world. Besides use in other various field as well, they are used extensively in the agriculture field in order to increase in the production by killing the pests that causes great economic loss. The use of the pesticides has been increasing day by day with increase in the commercialization of the agriculture production. Although using pesticides has benefits for the short period as it readily kills the pests, it has many others defects on the agricultural land, health of the users and water resources.

Applying of the pesticides in the crop not only kills the targeted crop but also many others beneficial insects which helping in controlling the natural enemies by maintaining the ecosystem. The micro organisms present in the soil are also affected which allocates the nutrient present in the soil to the plant. Due to this the number of the pests affecting the crop increases substantially in the next year and they began to develop the resistance against the pesticides By the killing of the micro organisms of the soil, there will be no biological activities in the soil such as decomposition of the organic matter and other degradable things so that the soil fertility will be reduce and become unproductive.

Also the chemicals have the persistant capacity to stay as the residual matter which may transfer from the soil to the crop and to the human body who consumes it. There will be bioaccumulation and bio magnification of the residues present which will bring different mutational effects such as birth of the abnormal child, health disorders, problem in the reproductive system, abortion, nausea, vomiting, headache and various other impacts.

The agricultural runoff of the chemicals used also caused harmful effects on the water resources. On the one hand the water will be polluted and at other the water ecosystem will be disturbed. The small fishes, zooplanktons and other aquatic plants will be suffered from the lack of oxygen due to eutrophication. The ground water leached from the surface may be contaminated with the chemicals in the highly used areas. Thus there is greater effects of the chemical pesticides used in the agricultural land on the human health, land itself and also on the water bodies, and are not environment friendly.