Agricultural science Sustainability 10 Soil science, sedimentology 9 Botany & plant sciences 8 Plant reproduction & propagation 8 Environmental management 7 Development economics & emerging economies 5 Climate change 4 Ecological science, the Biosphere 4 Environmental economics 4 Political economy 4 Agriculture & related industries 3 Central government policies 3 Forestry & silviculture: practice & techniques 3 Human geography 3 Meteorology & climatology 3 Political science & theory 3 The environment 3 Applied ecology 2 Biochemistry 2 Economic history 2 Economic theory & philosophy 2 Education 2 Environment law 2 Environmental monitoring 2 Environmental science, engineering & technology 2 Fertilizers & manures 2 Food & beverage technology 2 Gardening: growing fruit & vegetables 2 Historical geography 2