Paper 2 · Rainfall, humidity and the water cycle
Effective rainfall is
Athe part of the rainfall that enters the soil and is used by the crop
Bthe heaviest single fall of rain that is recorded in a given season
Cthe total rainfall recorded in the rain gauge over a whole season
Dthe rain that falls between the first planting rains and the last storm
Explanation: Not all rain reaches the crop. Some runs off the surface, some evaporates before it soaks in and some drains below the root zone. What is left in the root zone for the plant to use is the effective rainfall, which is why a heavy storm on a bare slope can be worth less than a steady soaking fall.
Derived from ZIMSEC Agriculture 5034/2 Paper 2, November 2014, Q1