IGCSE›Cambridge IGCSE Chemistry›Mind mapsFertilisersCambridge IGCSE Chemistry: Mind mapStudy pack PDFAlso for this subtopic:Revision notesFlashcardsSubtopic testCover factsWhat they areChemicals that replace nutrients used by plantsAmmonium salts supply nitrogenNitrates supply nitrogenRoots absorb nitrogen from the soilNPK fertilisersN is nitrogenP is phosphorusK is potassiumAll three together give improved growthFertilisersfeeding the soilNPKGetting into waterPlants do not absorb all the fertiliserExcess runs off fields into riversRivers gain nitrates from fertilisersPhosphates come from fertilisers and detergentsEutrophicationExcess nutrients over-fertilise algaeExcessive growth, then oxygen depletionFish and aquatic life dieBeneficial in soil, harmful in waterExam tipsRecall NPK: Nitrogen, Phosphorus, K potassiumLink run-off to eutrophicationSay oxygen falls as algae decompose