I have outlined the VERY BASIC idea behind crop rotation and the benefits of rotating crops and hazards of not doing so .
Nitrogen is CRUCIAL in sustaining agricultural or any life for that matter.
A historical example of destructive cropping came to America during the time of the dust bowl. Farmers had cropped the area out using cotton so badly that the soil was depleted of nitrogen and most other vital nutrients. What wasn’t was overran by insects and other non desirable creatures.
With that a man George Washington Carver had fostered the idea of rotating one year cotton to one year of soy, peanut , or other legumous plants . Basically what was found to happen was that the over cropping had destroyed the soil and depleted it of nitrogen . But through the rotation of said legumous plants soy and peanuts nitrogen was reintroduced to the soil through the decay of the plants.
Through a symbiotic relationship happening in the roots of these plants called rhyzobium nitrogen is produced.
Carver also brought out very many practical uses for the products created by this rotation to include food, fuel, medicine , and many other practical staple products many of us use today.
Good fast growing examples of this principle are mung, mongo , pole beans , and lentils.
You can inter sow certain crops with the perennial peanut to supplement that nitrogen fixation as well. This is a very good way of eliminating non natural inputs and also therefore limiting the chemicals we not only put into the earth but into ourselves.
ALSO for my mountainous farmers we can use this principle as a double edged sword so to speak. Shrubbery like ipil ipil , rensonii , and flemengia have three VERY PRACTICAL USAGES.
1. The deeper roots bring up nutrients from the depths of the soil to the surface
2. A VERY PRACTICAL AID IN FIGHTING EROSION IN THE MOUNTAINS ALA S.A.L.T (sloping agriculture land technologies).
3. Many of these plants you can double back and use as feeds for your animals to supplement protein.