Legume usage is Fundamental #2. It helps nitrogen fixation. Rotate a legume through every year to add free nitrogen to your system. This is one of the biggest expenses in chemical based agriculture and can be minimized and even replaced by biological practices.

Bacteria help the farmer by adding surplus nitrogen for the next crop. These microbes find the nitrogen in the air and soil, and then they capture [fix] it in small colonies on the roots of the peanut, soybean, pole beans, sitao, etc. The colonies can be seen on the root in small nodules.