Subject
- Agricultural ecology -- Oregon, Western1
- Agricultural productivity -- Oregon -- Willamette River Valley1
- Broccoli -- Yields -- Oregon1
- Conservation tillage -- Oregon1
- Conservation tillage -- Oregon, Western1
- Cover crops -- Oregon1
- Cover crops -- Oregon -- Willamette River Valley1
- Ground beetles -- Effect of pesticides on-- Oregon, Western1
- Ground beetles -- Environmental enrichment -- Oregon, Western1
- Herbicides1
- Metribuzin1
- Minimum tillage -- Oregon -- Willamette River Valley1
- Nitrogen fertilizers -- Oregon1
- No-tillage -- Oregon -- Columbia River Basin1
- Soils -- Quality1
- Tillage -- Oregon1
- Weeds -- Biological control -- Oregon, Western1
- Weeds -- Cultural control -- Oregon, Western1
- Weeds -- Integrated control -- Oregon, Western1
- Winter wheat -- Yields -- Oregon1