Basics of nutrient cycling ORGANIC ORGANIC MATERIALS MATERIALS AVAILABLE UNAVAILABLE AS NUTRIENTS AS NUTRIENTS Fossilization Livin Coal organisms, oil detritus peat Respiration, decomposition Assimilation excretion photosynthesis of fossil fuels ng Erosion. burn INORGANIC INORGANIC MATERIALS MATERIALS AVAILABLE AS NUTRIENTS Weathering, UNAVAILABLE erosion AS NUTRIENTS Atmosphere soil Minerals water Formation of in rocks sedimentary rock o1999 Hadson weeley Longman tne5 Basics of nutrient cycling