Soil Science
The medium everything else depends on — fertility, nutrients, organic matter, and testing that tells a farmer what a field is short of.
A recommendation that ignores the soil is a guess.
Soil science studies the physical, chemical and biological state of the ground: texture and structure, water holding, acidity and salinity, organic matter, and the availability of the nutrients a crop takes up. The Terai's soils vary sharply over short distances — a sandy river terrace and a heavy clay can sit within one village — so a blanket fertiliser recommendation is close to useless.
The discipline runs soil testing and interprets it into a nutrient recommendation by crop and season; studies organic matter, residue return and manure in a system where straw is also fodder and fuel; and works on the problem soils of the province — waterlogged, saline and degraded land that ordinary practice does not fix.
Soil testing
Sampling, laboratory analysis and interpretation into a recommendation.
Nutrient management
Fertiliser and manure recommendations by crop, soil and season.
Organic matter
Residue return, composting and manure in a straw-scarce system.
Problem soils
Waterlogged, saline and degraded land of the province.