"Hungria" cant have a better name for food research. Nitrogen fixing is one of the more frustrating things to work on as there is such a massive ready supply of unfixed nitrogen to work with everywhere on our planet and all in all we need such a tiny proportion to dramiticly improve agriculture.The whole thing is so finly balanced that herbivors can likely smell the diference in plants that have been given nitrogen fertiliser and raid our crops and gardens for the fixed nitrogen that then facilitates there own internal bacteria and thereby achive better nutrition for themselves. But to my frustration and anger, nothing eats alder bushes, which are a never ending problem in taking over fields, but when after employing machinery to uproot them,( it bieng the only way to kill them), reveals there bright orange knobly roots, that host the nitrogen fixing bacteria that they contain. There is enough nitrogen and other nutrients in alder that the area's where they are piled and burnt will remain significantly more fertile for many years after. One of my(many) projects is to experiment with "terra preta" and build a charcoal kiln, primarily for alder and hopefully be able to retain a greater portion of the "good stuff™" that is otherwise lost to rotting or combustion.