Environment and Sustainable Agriculture
Environment and Sustainable Agriculture
This domain examines pollution, pesticide hazards, soil and water conservation, organic farming, conservation agriculture, biodiversity and climate-smart practices.
Core rules
- Sustainable agriculture aims to maintain productivity while protecting soil, water, biodiversity and human health.
- Conservation agriculture rests on minimum soil disturbance, permanent soil cover and crop rotation.
- Organic farming avoids synthetic fertilisers and pesticides and relies on organic manures, compost, biofertilisers and biological control.
- Pesticide pollution depends on toxicity, persistence and dose; safe use includes correct dose, protective clothing and a pre-harvest interval.
- Carbon sequestration in soil is increased by organic matter addition, reduced tillage and cover crops.
Worked example
A farmer applies 100 kg urea containing 46% nitrogen. Nitrogen applied = 100 × 0.46 = 46 kg N. If 30% is lost by volatilisation, the loss is 46 × 0.30 = 13.8 kg N, leaving 32.2 kg N. The reasoning is to convert the fertiliser weight to nutrient weight first, then apply the loss percentage.
Mark-losing traps
- Equating organic farming with zero nutrient inputs; organic sources still supply nutrients.
- Treating conservation agriculture as zero tillage alone and omitting cover and rotation.
- Confusing pesticide persistence with immediate toxicity.
- Applying a loss percentage to fertiliser weight instead of nutrient weight.