IMPACT OF PESTICIDE IN SOIL

this presentation describes

1. TOPIC-IMPACT OF PESTICIDE IN SOIL & SOIL MICRO-ORGANISM SOIL BIOLOGY & BIOCHEMISTRY PRESENTED BY STANLEY SAMUEL MSc AG 1 ST YEAR DEPT.OF SOIL SCIENCE

2. content 1. Pesticides 2.types of pesticides in the soil 3.polar and non polar pesticides 4.impact of pesticides in soil 5.effect one enzyme 6.negative impact conclusion

3. PESTICIDES : Pesticides are chemical compounds that are used to kill pests, including insects, rodents, fungi and unwanted plants (weeds ). By their nature, pesticides are potentially toxic to other organisms, including humans, and need to be used safely and disposed of properly. classification in relation with soil: 1.Non-polar pesticides 1.HYDROPHOBIC,PERSISTANT AND ACUMUABLE PESTICIDE THAT ARE STRONGLY BOUND TO SOIL. Organochlorines,DDT,ENDOSULFAN,ENDRIN,LINDANE .

4. Polar pesticides Mainly herbicides but they include carbamates,fungicides and organophosphorus insecticides. They can be moved from soil by runoff and leaching ,thereby constituting a problem for the supply of drinking water to the population

5. Impact of pesticides:- Though beneficial ,they contaminate soil and pose threat to balance equilibrium to various organism and to the component of the soil. Process like mineralisation,nitrification and phosphorous cycling are dependent much on balanced equilibrium. Disturabance in soil enzyme.

6. Soil contamination - pesticides have characteristics of mobility, persistence in soil which determine the action in soil. Effect on soil fertility- 1.By effecting micro-organism which utilizes soil store water and nutrient ,regulate water flow and filter pollutants . 2.Declination in population of beneficial micro-organism. 3.Negative impact on available NPK in the soil.

7. Research in effects on soil micro-organism

8. Effect on enzyme: Mainly enzyme that effected are:- 1.Dehydrogenase 2.Phospahatase 3.Urease

9. Dehydrogenase 1.Role –in the process of organic matter oxidation mainly in the electron transfer reaction. 2.Impact-dehydrogenase does not accumulate in soil. Phosphate and urease Role-mineralisation ,nitrification of organic substrate and soil biological activity .

10. NEGATIVE IMPACT There is evidence that prolonged use of heavy doses of fertilisers can result in soils becoming more acidic that has serious implications in terms of long term productivity of soils. The excessive agrochemicals application reduces the biodiversity of the soil. The microorganisms of soil are more spoiled by soil disturbance by application of chemicals than any other parameters. beneficial microorganisms in soil have declined due to overuse of pesticides, which has a negative impact on the available nitrogen, phosphorus and potassium (NPK) from soil ( Sardar and Kole , 2005), thereby degrading the soil quality.

11. Fungicides generally had even greater effects on soil organisms than herbicides or insecticides. As these chemicals are applied to control fungal diseases, they will also affect beneficial soil fungi and other soil organisms Copper- based fungicides were found to have very significant negative effects, which caused long-term reductions of earthworm populations in soil

12. Organophosphate insecticides ( chlorpyrifos , quinalphos, dimethoate , diazinon , and malathion) had a range of effects including changes in bacterial and fungal numbers in soil (Pandey and Singh 2004), varied effects on soil enzymes ( Menon etal . 2005; Singh and Singh 2005), as well as reductions in collembolan density ( Endlweber et al . 2005) and earthworm reproduction (Panda and Sahu 1999). organochlorine and organophosphorus pesticides suppress symbiotic nitrogen fixation resulting in lower crop yields. (Fox et al., 2007; Potera 2007).

13. CONCLUSION Difficult to explore all ramification of pesticides 2.Major biotic process such as enzyme activity,respiration,carbon and nitrogen and mineralization are majorly affected.

14. REFERENCE: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2984095 / https:// www.slideshare.net/reddevil04/impact-of-pesticides-on-soil https://www.researchgate.net/.../301542254_Impact_of_Fertilizers_and_Pesticides_

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