Subject
- Acid soils -- Oregon -- Willamette River Valley1
- Alfalfa -- Oregon -- Willamette River Valley -- Growth1
- Clover1
- Cornstalks -- Nitrogen content -- Oregon -- Willamette River Valley1
- Fisheries -- By-products1
- Forage plants -- Fertilizers1
- Forest soils -- Oregon1
- Fruit -- Soils1
- Liming of soils1
- Mycorrhizas1
- Organic wastes as fertilizer1
- Plants, Effect of soil acidity on1
- Plants, Effect of sulphur on1
- Soils -- Boron content1
- Soils -- Nickel content1
- Soils -- Nitrogen content -- Oregon -- Willamette River Valley1
- Soils -- Oregon1
- Soils -- Oregon -- Willamette River Valley -- Analysis1
- Soils -- Potassium content1
- Wheat -- Fertilizers1