SUBJECT
Terracing
Rice
11
Planting
8
History
6
Agriculture
5
Antiquities
5
Ifugaos (Philippine people)
4
Irrigation
4
Ifugao (Philippine people)
3
Rice farming
3
Social life and customs
3
Social structure
3
Agricultural conservation
2
Agricultural system
2
Archaeology
2
Conservation and restoration
2
Description and travel
2
Earthworms
2
Ifugao Rice Terraces
2
Landscapes
2
Rice planting rites
2
Social conditions
2
Tourism
2
Agricultural surveys
1
Agricultural systems
1
Azolla
1
Commerce
1
Conservation and preservation
1
Contingent valuation
1
Cyanobacteria
1
Deepwater rice
1
Economic aspects
1
Electronic books
1
Environmental monitoring
1
Environmental protection
1
Ethnohistory
1
Finance
1
Geographic information systems
1
Groundwater flow
1
Hydraulic engineering
1
Hydrology
1
Ifugao rice terraces
1
Incas
1
Irrigation farming
1
Javanese (Indonesian people)
1
Land use
1
Management
1
Natural resources
1
Nitrogen-fixing algae
1
Payments for ecosystem services
1
more ...