Related by context. Frequent words. (Click for all words.) 71 nutrient pollution 64 polluted runoff 59 soil erosion 59 eutrophication 58 stormwater runoff 58 salinity 58 pollution 57 nitrous oxide emissions 57 sedimentation 56 nitrogen 56 algal blooms 55 algae blooms 55 pollutants 54 phosphorus 53 soil compaction 53 groundwater pumping 53 greenhouse gasses 53 impervious surfaces 53 groundwater recharge 53 nutrient 53 nitrogen fertilizers 52 phosphorous 52 TMDL 52 soil fertility 52 dissolved oxygen 51 sewer overflows 51 sediment 51 sewage overflows 51 siltation 51 carbon sequestration 51 aquatic vegetation 50 wetlands 50 oxygen depletion 50 deforestation 50 acidification 50 overgrazing 50 wetland restoration 50 pollutant 50 conservation tillage 50 watersheds 49 estuaries 49 crop residue 49 greenhouse gases 49 impervious surface 49 stormwater 49 aquatic habitat 49 toxic algae 49 algae 49 crop yields 49 overfishing 49 irrigated agriculture 49 wildlife habitat 49 wastewater discharge 48 tillage 48 invasive weeds 48 acid rain 48 anthropogenic 48 carbon sinks 48 wetland 48 carbon dioxide 47 algal 47 manure 47 croplands 47 nutrients 47 waterways 47 alkalinity 47 air pollution 47 cropland 47 rotenone 47 freshwater 47 groundwater 47 invasive species 47 GHGs 47 tributaries 47 nitrogen fertilizer 47 transpiration 47 biodiversity 47 hypoxia 47 purple loosestrife 47 Sediment 47 silting 46 sequester carbon 46 vegetation 46 eelgrass 46 greenhouse gas 46 mercury pollution 46 soils 46 aquatic organisms 46 spawning habitat 46 greenhouse gas emissions 46 biofuel crops 46 nutrient rich 46 atmospheric carbon dioxide 46 herbicides 46 Invasive species 46 greenhouse emissions 46 Pollutants 46 corn ethanol 45 greenhouses gases 45 defoliation 45 forage