Theory question 104
Soil Fertility and Plant NutritionWrite short notes on the following:
(a) bush burning.
(b) clean clearing.
(c) organic manuring.
Show the model answer
(a) Bush burning: clearing by setting fire to vegetation; cheap and quick, kills pests and weed seeds, ash adds potash; but destroys organic matter and soil organisms, loses nitrogen and sulphur, exposes soil to erosion, pollutes air
(b) Clean clearing: complete removal of all vegetation and debris; makes tillage and mechanisation easy; but exposes soil to sun, erosion and leaching, loses organic matter
(c) Organic manuring: adding decayed plant and animal materials (farmyard manure, compost, green manure, poultry droppings); adds nutrients slowly, improves structure, water holding, aeration and microbial activity; bulky, low nutrient content, may carry weeds and diseases
Give meaning, benefits and drawbacks for each.