Fertile soil is one which
- which easily drained
- is well aerated
- can produce a good harvest of cowpea
-
contain all essential plant nutrients in suitable proportion
The correct answer is: D
Explanation
Fertile soil is one which contains all the plant nutrients in the right proportion.
A fertile soil will contain all the major nutrients for basic plant nutrition (e.g nitrogen, phosphorus and potassium), as well as other nutrients needed in smaller quantities (e.g calcium, magnesium, sulfur, ion e.t.c).