An indigenous method of renewing and maintaining soil fertility is by

Analyze the question: It asks for an indigenous (traditional, local) method of renewing and maintaining soil fertility. So we need a practice that traditional farmers use to restore nutrients naturally.

Concept:

• Crop rotation: Different crops are grown in sequence on the same land. Legumes (beans, groundnut, cowpea) fix nitrogen in the soil, and different crops use different nutrients, so the soil isn't drained of any single one.
• Shifting cultivation: Farmers cultivate a piece of land for a few years, then move to a new plot and leave the old one fallow. During the fallow period, vegetation regrows, and decaying plant matter restores humus and nutrients.

Both are traditional, low-cost methods that restore soil fertility.

Evaluate the options:

• A. Clearing farms by burning: This is a land-preparation method. It gives a short-term nutrient boost from ash, but it destroys humus and soil organisms and exposes the soil to erosion. It does not maintain fertility.
• B. Planting one crop type (monoculture): This depletes the same nutrients repeatedly and encourages pests and diseases. It lowers fertility.
• C. Adding inorganic fertilizers yearly: This is a modern, not indigenous, method. It also costs money and can damage soil structure over time.
• D. Crop rotation and shifting cultivation: These are traditional practices that let the soil recover naturally. This fits the question.

Answer: D

Exam tip: When you see the word "indigenous" or "traditional" in a farming question, think of crop rotation, shifting cultivation, bush fallowing, and mixed cropping. Words like "inorganic" and "fertilizers" usually point to modern methods.