Fertilisers And Eutrophication

• natural (organic) fertilisers • artificial (inorganic) fertilisers

Dead and decaying plants, animals and waste including manure and bone meal

Mined from rocks and blended to give the right mix of nutrients for particular crops - NPK - nitrogen, phosphorus, potassium

• needed for DNA and proteins, both for plant growth • likely that plants develop earlier and grow taller • increased leaf area results in increased rate of photosynthesis • increased crop productivity

• needed for production of ATP and nucleotides in DNA and RNA • important for semi-conservative replication and protein synthesis

• involved in the movement of water and carbohydrates and protein synthesis in plants • role in activation of enzymes and production of ATP

• NPK fertilisers favour the growth of grasses, nettles and rapidly growing species • these plants outcompete slower growing species

• the removal or loss of nutrients from the soil

• rain water dissolves soluble nutrients • this carries them away from the reach of the roots • water drains into water sources such as lakes and rivers

• dangerous if the water source is drinking water • can lead to eutrophication

• fertilisers wash into a lake or river • algae grow faster - algae die • plants shaded by algae - some plants die • dead algae and plants decomposed by microbes (saprobionts) • microbes respire and use up oxygen • dissolve oxygen levels fall • aquatic animals suffocate and die