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.
This article focuses on legumes, which are nitrogen fixers of particular importance in agriculture. Specifically, three legumes (nitrogen fixing trees, hereafter called NFTs) are especially valuable in subtropical and tropical permaculture. They can be integrated in a permaculture system to restore nutrient cycling and fertility self-reliance.