Here is the answer for question number 11 you asked above i.e. about meaning of nitrogen fixing plants and their importance .Nitrogen fixing plants are those plants which help to covert atmospheric nitrogen in to compounds which are usable by plants. Plants like peas, beans are famous for their symbolic nitrogen fixing. Importance of Nitrogen fixing plants in Permaculture is that when plants intake nitrates which are used by them to get some energy and growing so that they can mature and produce seeds. These seeds are growing in to new plants. When plants like peas and beans which are also called legumes die, they decay into the soil, releasing compounds which contain nitrogen and can be used by other plants. Once plants get going, in other words, they can set up a system which will perpetuate as older plants die to make room for younger ones, sharing fertilizer as they break down.
