decomposition is when a decomposer recycles nutrients from dead organisms to the soil by eating those dead organisms & decomposition increases the amount of nutrients / nitrogen in the soil -> decomposers can decrease the chain of weight in the sand decomposers can increase the amount of nutrients in the soil  decomposers can increase the amount of nutrients in the soil & an earthworm is a kind of decomposer & green is a mean of sand -> earthworms can increase the amount of nutrients in the topsoil