Q. Fertility of soil can be improved by : [IAS 1989] (Solved)
1. adding living earthworms
2. adding dead earthworms
3. removing dead earthworms
4. removing living earthworms and adding dead earthworms
- a. adding living earthworms
1. adding living earthworms
2. adding dead earthworms
3. removing dead earthworms
4. removing living earthworms and adding dead earthworms