1. Soil is highly rich in microorganisms such a bacteria, fungi, protozoa, micro arthropods.
2. The top eight inches of soil of one acre many contain as much as five and half tons of fungi and bacteria.
3. This is very much useful for growing crops.
4. Excess use of pesticides kills these bacteria.
5. Thus human actions causing death of useful bacteria and fungi.
6. If it happens continue, then it causes to ecological imbalance.
