Dr Rana Hamza Shakil thank you for your contribution to the discussion

Nutrient cycles as biogeochemical cycles, describe the movement of chemical elements through different media, such as the atmosphere, soil, rocks, bodies of water, and organisms. Nutrient cycles keep essential elements available to plants and other organisms. It is a natural recycling system of mineral nutrients. Nutrients consumed by plants and animals are returned to the environment after death and decomposition and the cycle continues. Soil microbes play an important role in nutrient recycling. They decompose organic matter to release nutrients. Nutrient cycles allow for the storage of elements, which is important because certain organisms only require a small quantity of a particular nutrient to sustain life. In a nutrient cycle, elements remain stored in their natural reservoirs, and are only released to different organisms in an appropriate quantity. Soil microbes play an important role in nutrient recycling. They decompose organic matter to release nutrients. They are also important to trap and transform nutrients into the soil, which can be taken up by plant roots. Nutrient cycling rate depends on various biotic, physical and chemical factors. Bacteria break down dead organisms, animal waste, and plant litter to obtain nutrients. But microbes don't just eat nature's waste, they recycle it. The process of decomposition releases chemicals that can be used to build new plants and animals. Microbes help digest food, absorb nutrients, and out-compete harmful bacteria in the intestines. They produce vitamins and proteins that human genes cannot produce. They prevent the growth of harmful skin bacteria and further aid the immune system in fighting infections and diseases throughout the human body. When microbes die, they decompose, releasing ammonium and tiny particles containing particulate organic nitrogen (PON), as well as dissolved organic nitrogen (DON) into the surrounding seawater. Some microbes convert ammonium to nitrite (NO2-) and then nitrite to nitrate (NO3-). In the ocean, blue-green cyanobacteria are the most abundant type of bacteria to fix nitrogen. Collectively, these organisms are called diazotrophs, and account for close to 90% of natural nitrogen fixation.