Correct Option
The correct option is (c) 2 and 3 only.
Explanation
Soil supplies mineral nutrients to crop plants, which are essential for their growth. To maintain soil fertility and ensure healthy yields, farmers add substances in the form of manure and fertilizers to replenish nutrients depleted by farming.
Statement-wise Analysis:
- Statement 1 is Incorrect: Continuous cultivation of crops on the same land makes the soil poor in certain nutrients. Plants absorb minerals from the soil for growth; if crops are grown continuously without allowing the soil to recover (fallow periods) or without replenishment, the nutrient levels deplete rather than enrich.
- Statement 2 is Correct: Manure is a natural, organic substance obtained from the decomposition of plant or animal wastes (such as cow dung, urine, and crop residues). It provides a lot of humus to the soil, improving its texture and water-retaining capacity, though it is relatively less rich in specific plant nutrients compared to fertilizers.
- Statement 3 is Correct: Fertilisers are chemical substances produced in factories that are rich in specific plant nutrients. The most common nutrients found in fertilizers are Nitrogen, Phosphorus, and Potassium (often referred to as NPK). Examples include Urea, Ammonium Sulphate, and Super Phosphate.
Key Takeaway:
Manure is an organic substance that adds humus and improves soil structure, whereas fertilizers are nutrient-specific chemicals (NPK) used for rapid plant growth but can degrade soil health if used excessively.