Which of the following practices improves crop yield in a clayey soil? Addition of

Analyze the question: Clayey soil has very fine particles. It is poorly aerated, drains badly, becomes waterlogged, is sticky when wet and hard when dry, and is often acidic. The question asks which practice would improve crop yield in such soil.

Explain the concept:

• Humus (decayed organic matter) improves soil structure. It binds clay particles into crumbs, which opens up air spaces, improves drainage and aeration, and adds nutrients.
• Lime (calcium carbonate or calcium hydroxide) helps in clay soils in two ways. It causes clay particles to flocculate (clump together), which improves drainage and aeration. It also reduces acidity, which clayey soils from waterlogging and leaching often have.
• Water is already held in excess by clay, so adding more makes waterlogging worse.
• Fertilizers and weedicides add nutrients or kill weeds, but they do nothing to fix the poor structure and drainage that limit yield in clay.

Step-by-step evaluation:

• A. More water and humus: extra water worsens waterlogging. Wrong.
• B. Lime and humus: both improve structure, aeration, and drainage. Correct.
• C. Fertilizers: add nutrients only and do not correct the structure problem. Not the best answer.
• D. Weedicides and fertilizers: neither addresses the soil texture problem. Wrong.

**Answer: B. Lime and humus.

Exam tip: Match the treatment to the soil problem.

• Clay (heavy, waterlogged): add lime and humus to loosen it.
• Sandy (drains too fast): add humus to hold water and nutrients.

Whenever you see "clay" in a question, think "improve drainage and aeration," and avoid options that add water.