Agriculture Economic aspects 242 History 176 Economic conditions 65 Environmental aspects 63 Agriculture and state 59 Social aspects 45 more ... Social conditions 37 Rural conditions 36 Food supply 35 Research 32 Food 27 Rural development 27 Peasants 26 Land tenure 24 Politics and government 21 Antiquities 19 Social life and customs 19 Government policy 18 Sustainable agriculture 17 Origin 16 Agricultural ecology 15 Food industry and trade 14 Human ecology 14 Land use, Rural 14 Climatic changes 13 Indians of North America 13 Agricultural productivity 12 Agriculture, Prehistoric 12 Farm life 12 less ...