Answer:
1.
Positive Effects
The use of organic fertilizers has advantage of being cheap, improving soil structure, texture and aeration increasing the soils water retention abilities and stimulating healthy root development. Organic fertilizer has many sources such as minerals, animal source, sewage sludge and plant.
Negative Effects
However, the use of excess fertilizer can result in a number of problems, such as nutrient loss, surface water and groundwater contamination, soil acidification or basification, reductions in useful microbial communities, and increased sensitivity to harmful insects.
2. Organic fertilizers also help improve the structure of the soil including the circulation of air, which sustains beneficial microorganisms that help release nutrients to the soil. In many agriculture areas, pollution of groundwater causes with synthetic fertilizers and pesticides.