Soil, Water and Nutrient Management in Horticulture
Domain 6 tests soil assessment, irrigation scheduling and fertilizer calculation for horticultural crops. It combines soil texture and pH with practical water and nutrient decisions. In Odisha, laterite and red soils, monsoon leaching and acidic pockets are common considerations.
Core rules
- Soil texture affects water holding, aeration and root growth. Sandy soil drains quickly; clay soil holds water but may waterlog.
- Soil pH controls nutrient availability. Most horticultural crops grow well near pH 6.0 to 7.0, but crops differ.
- Organic matter improves structure, water holding and biological activity. Use well-rotted manure or compost.
- Irrigate according to crop stage, soil moisture and weather. Critical stages such as flowering and fruit development are especially sensitive.
- Fertilizer recommendations are usually given as nutrient, not product. Convert using the nutrient percentage on the bag.
- Split nitrogen application reduces leaching loss. Place phosphorus where roots can reach it.
Worked example
A recommendation is 100 kg nitrogen per hectare. The available fertilizer is urea containing 46% nitrogen. Product required = 100 ÷ 0.46 = 217.4 kg urea per hectare. If the recommendation were 50 kg N, the amount would be 50 ÷ 0.46 = 108.7 kg urea. The calculation uses the nutrient fraction, not the bag weight.
Traps that cost marks
Do not apply 100 kg urea when 100 kg nitrogen is required. Do not confuse pH 5 with pH 7 as equally acidic. Do not irrigate by habit without checking moisture. Do not ignore leaching after heavy rain.