SUBJECT
Soils
Rice
4
Classification
3
Soil fertility
3
Research
2
Soil conservation
2
Agricultural innovations
1
Agriculture
1
Environmental aspects
1
Fertilizers
1
Fertilizers and manures
1
Fixation
1
Heavy metal content
1
Heavy metals
1
Land
1
Leaching
1
Lysimeter
1
Nitrogen
1
Nitrogen content
1
Organic fertilizers
1
Physiological effect
1
Plant-soil relationships
1
Plants, Effect of heavy metals on
1
Plants, Effect of nitrogen on
1
Soil absorption and adsorption
1
Soil management
1
Soil percolation
1
Soil productivity
1
Soil surveys
1
Soils, Salts in
1
Study and teaching
1
Technology transfer
1
Topographical surveying
1
Trace elements
1
Trace elements in agriculture
1
Trace elements in plant nutrition
1
Varieties
1
Water-supply
1