As the members of a given generation age, their instinct of social conservation becomes stronger, which inevitably and necessarily brings them into conflict with the normal attribute of youthâinnovation. Other important theorists of the 19th century were John Stuart Mill and Wilhelm Dilthey.
Plants require more than just water and sunlight to grow. They also require many nutrients found in the soil. One of the most important nutrients required for plant growth is nitrogen. Nitrogen is used to build plant proteins and nucleic acids, including DNA.
However, nitrogen can be converted into forms usable by plants and animals, either by lightning or bacteria. Once converted to usable forms, nitrogen is able to cycle the rest of the way through the ecosystem. As mentioned, the atmosphere is the largest reservoir of nitrogen.