Related by context. Frequent words. (Click for all words.) 73 Nitrogen 65 nutrient 65 nitrogen fertilizer 65 phosphorus 63 carbon dioxide 60 ammonia 59 methane 59 nutrients 58 fertilizer 58 phosphorous 58 CO2 57 soils 57 sulfate 56 carbon dioxide CO2 56 phosphates 56 nitrate 55 dissolved oxygen 54 sulfur 54 urea 54 sediment 53 water vapor 53 gases 53 selenium 52 fertilizers 52 manure 52 pH 52 algae 51 Carbon dioxide 51 sulfur dioxide 51 salinity 51 phosphate 51 phytoplankton 50 oxygen 50 pollutants 50 pollutant 50 chloride 50 photosynthesis 50 atmospheric carbon dioxide 50 aeration 50 boron 50 calcium carbonate 49 soil moisture 49 glyphosate 49 moisture 49 soil fertility 49 chlorophyll 49 contaminant 49 nutrient rich 48 potassium 48 salts 48 chlorine 48 hydrogen 48 herbicide 48 magnesium 48 starch 48 sedimentation 48 nitrates 48 silt 47 hydrogen sulfide 47 greenhouse gases 47 NOx 47 contaminants 47 plankton 47 organic compounds 47 calcium 47 ozone 47 coolant 47 nitrogen oxides 47 greenhouse gas 46 fungicide 46 micronutrients 46 herbicides 46 effluent 46 seawater 46 topsoil 46 compost 46 sediments 45 refrigerant 45 sandy soil 45 forage 45 oxidation 45 solids 45 chemicals 45 fatty acids 45 silage 45 legumes 45 volatile organic compounds 45 nitrogen oxide 45 lipid 45 viscosity 45 grasses 45 groundwater 45 helium 45 soil 45 chemical fertilizers 45 Fertilizer 45 carbon sequestration 45 fertilizing 45 microorganisms 45 Methane 45 slurry