Paper 2 · Soil Fertility and Plant Growth
Plant nutrients are lost from the soil when
Aa legume is grown on the land and its residues are ploughed back in
Bkraal manure is applied to the land before the crop is planted out
Cthe land is left under a grass ley for two seasons in succession
Dsoluble nutrients are leached down below the reach of the crop roots
Explanation: Leaching carries dissolved nutrients, nitrate above all, down past the depth the roots work. The other three practices all return nutrients or organic matter to the land.
Derived from ZIMSEC Agriculture 5035/2 Paper 2, November 1997, Q2