How do living organisms contribute to the fertility of the soil?

Question

How do living organisms contribute to the fertility of the soil?

Answer 1

Living organisms contribute organic materials to the soil either when they pass on or when parts of them falls to the soil. For example, when a tree sheds its leaves, a deciduous tree, in the northern hemisphere, there are organic compounds in the leaves which once in the soil are known as detritus. Bacteria do break them down. Earthworms will consume the bits of decaying leaves and further add to the nutrients of the soil.

Answer 2

people and animal wastes cold be used to fertilize the soil. bacteria in the plant's roots use nitrogen fixation to supply the plant with nitrogen. most plants lack nitrogen.

humans can contribute negatively to the soil. overfarming of the same part of the soil for a long time exhausts the soil of its minerals. that why ancient farmers leave soil fallow(unplanted) for a while then go back to it.