Water conservation 146 Irrigation 32 Soil conservation 20 water conservation 19 Soil and water conservation 11 Erosion: Soil and Water Conservation 9 Water 9 Watershed management 9 WATER CONSERVATION 8 Water-supply 8 Erosion 7 Soil science 7 Water resources development 7 Land degradation 6 Pollution and Degradation 6 Water use 6 Soil management 5 Water Resources 5 Agricultural Economics 4 Agroforestry 4 Drainage 4 Natural Resource Economics, (New March 2000) 4 Soil Chemistry and Mineralogy 4 Soil Fertility 4 Soil conservation-India 4 Soil erosion 4 Soil fertility 4 Soil types 4 Surveying 4 Water Conservation 4