Related by context. Frequent words. (Click for all words.) 65 nitrogen fertilizers 60 livestock manure 59 phosphorus 58 herbicides pesticides 58 nitrogen 57 groundwater withdrawals 57 nitrogen fertilizer 57 nutrient loading 56 phosphate fertilizers 56 nitrogen phosphorous 56 lawn fertilizers 56 Nitrates 56 Fertilizing 56 phosphorous 56 recharge groundwater 56 nitrification 55 ammonia nitrogen 55 barley straw 55 fertilizers 55 Drip irrigation 54 polluting waterways 54 toxic residues 54 rice hulls 54 absorbs carbon dioxide 54 fertilizer 54 phosphates 54 pesticides fertilizers 54 Sulfate 54 dishwasher detergents 53 fumigants 53 nutrient runoff 53 crop residues 53 fluorocarbons 53 adipic acid 53 inorganic fertilizers 53 biosolid 53 liquid fertilizers 53 elemental sulfur 53 triclocarban 52 fluorochemicals 52 nitrogen phosphorus 52 soil salinity 52 manures 52 Methyl bromide 52 acidify 52 salination 52 Chlorpyrifos 52 pesticides 52 agrichemicals 52 nutrient 52 PCBs polychlorinated biphenyls 52 oxalic acid 52 manure piles 52 Kuan Yin Taiwan 51 Residues 51 Soda ash 51 pasture grasses 51 chlorides 51 pollutant discharge 51 Anhydrous ammonia 51 contaminate groundwater 51 Septic tanks 51 potassium permanganate 51 acidifying 51 Paraquat 51 chicken manure 51 Rotenone 51 carbaryl 51 chemical fertilizers 51 isopropanol 50 carbofuran 50 nitrates 50 aluminum sulfate 50 acidic soils 50 Temik 50 chemicals 50 toxic solvents 50 fertilizers pesticides 50 Nitrogen 50 Reverse osmosis 50 crop residue 50 nitrous oxides 50 phosphine 50 hydrated lime 50 harmful contaminants 50 Stormwater runoff 50 potent greenhouse gas 50 alkaline soils 50 soil conditioner 50 phosphate fertilizer 50 Invasive plants 50 Grass clippings 50 deplete oxygen 50 sulphate 50 ammonium sulfate 50 manure 50 diazinon 50 hexane 50 diatomaceous earth 50 bio solids 49 Biosolids