Subject
Soils
8
Meteorology
2
Tobacco
2
Agricultural chemistry
1
Agriculture
1
Alkali lands
1
Analysis
1
Atmospheric temperature
1
Corn
1
Crop zones
1
Earth temperature
1
Fertilizers
1
Histoire
1
History
1
Measurement
1
Meteorological instruments
1
Soil moisture
1
Soil physics
1
Soil surveys
1
Soil temperature
1
Soils, Salts in
1
Sols
1
Thermometers
1
Tobacco curing
1
Tobacco industry
1