Agriculture History 252 Economic aspects 99 Environmental aspects 61 Research 60 Food supply 55 Agricultural ecology 45 more ... Agriculture and state 36 Farm life 36 Agricultural innovations 32 Sustainable agriculture 26 Food 25 Organic farming 25 Social aspects 24 Country life 21 Landwirtschaft 21 Soils 21 Economic conditions 20 Farms 18 Farmers 17 Rural conditions 17 Government policy 16 Agricultural productivity 12 Farms, Small 12 Irrigation 12 Soil conservation 12 Agricultural conservation 11 Food crops 11 Gardening 11 AGRICULTURE 10 less ...