(a) (i) Define the term drainage.
(ii) State four reasons why waterlogged agricultural land should be drained. 

 

(b)List six factors affecting nutrient availability in the soil.

(c) Complete the table below on the causative organisms of crop diseases.

Disease	Causative Organism
Rice blast	(i)
Groundnut rosette	(ii)
Cassava mosaic	(iii)
Root knot of tomatoe	(iv)
Maize rust	(v)
Tristeza	(vi)