Land management 15 Land Resources 6 Land use 6 Sustainability 5 Water management engineering 5 agricultural engineering 5 land management 5 land resources-agriculture 5 Agroforestry 4 Soil conservation 4 Biological Resources (General) 3 Forest management 3 Natural Resource Economics, (New March 2000) 3 Pollution and Degradation 3 Silviculture and Forest Management 3 Social Psychology and Social Anthropology, (New March 2000) 3 Water management 3 Biodiversity 2 Case studies 2 Conflict 2 Cropping systems 2 Environmental degradation 2 Environmental management 2 Field Crops, (New March 2000) 2 Forests 2 Forests and Forest Trees (Biology and Ecology) 2 Land use, Rural 2 Nature conservation 2 Pests 2 Plant Cropping Systems 2