Theory question 104
Soil Fertility and Plant NutritionDescribe briefly the effects of the following farming practices on the soil:
(a) bush burning
(b) overgrazing
(c) clean clearing
(d) fertilizer application.
Show the model answer
Model answer
(a) Bush burning: destroys organic matter and soil organisms; loss of nitrogen and sulphur; exposes soil to erosion; ash adds potassium and raises pH temporarily
(b) Overgrazing: removes plant cover; trampling compacts soil; erosion and loss of fertility
(c) Clean clearing: soil exposed to sun, rain and wind; erosion, leaching and loss of organic matter; high soil temperature kills organisms
(d) Fertilizer application: adds nutrients and raises yield; excess or wrong use causes acidity, salt build-up, harm to soil organisms and water pollution
Explanation
Give the main effect of each practice on soil.