Agriculture: Cropping Systems, Soil Fertility and Crop Protection
Core concepts
Agriculture questions test whether you can connect soil, water, seed, nutrient and pest decisions into one system. Know the difference between agronomic crops (cereals, pulses, oilseeds, fibres) and horticultural crops (fruits, vegetables, flowers). Distinguish kharif (monsoon-sown), rabi (winter-sown) and zaid (short summer) seasons, and be able to name a crop for each.
Soil science essentials: soil texture classes (sand, silt, clay, loam) and how they govern water-holding and drainage; cation exchange capacity and why clay and organic matter raise it; soil pH and the availability of N, P, K and micronutrients across the pH range. Fertiliser arithmetic matters: urea is 46% N, DAP is 18% N and 46% P2O5, MOP is 60% K2O. Understand critical stages of irrigation (e.g., crown-root initiation in wheat, flowering in most crops) and the meaning of duty and delta.
Crop protection: differentiate fungicide, insecticide, herbicide, nematicide; know the terms systemic vs contact, selective vs non-selective, and the idea of economic threshold level. Integrated pest management (cultural, mechanical, biological, chemical) is a favourite theme. Seed: viability, germination percentage, and the difference between certified and foundation seed.
Traps
Questions swap kharif/rabi labels, confuse DAP with SSP (SSP also supplies sulphur and calcium), or ask for the nutrient rather than the fertiliser. Watch for 'which is a legume' (pulses fix nitrogen via Rhizobium) versus 'which is an oilseed'. Do not assume all cereals are kharif.
Worked rule of thumb
Fertiliser quantity = (recommended nutrient ÷ % nutrient in fertiliser) × 100. For 60 kg N/ha using urea: (60 ÷ 46) × 100 ≈ 130 kg urea per hectare. Apply this formula before reading the answer choices.