There are already some solutions to handle the fertilizer problem all around the world:
For rice it is even possible to produce more food without chemical fertilizer:
It's called the "Duck revolution". Invented by TAKAO FURUNO, a japanese peasant. He is practicing ecological farming since 1977 and in 1987 he got the idea to combine rice farming and growing ducks at the same place. Gradually he enhanced his idea by adding other organisms to his system. He published in 2001 all his knowledge in the book "The power of duck". The result of his work is the combination of rice growing together with growing of ducks and fishes in a paddy.
Even better is to let grow different sorts of Azolla (
http://en.wikipedia.org/wiki/Azolla ), a aquatic fern in the paddies. Azolla works like legumes in fixing nitrogen from the atmosphere in the ground respectively in the water.
For crops/grains:
- Inter cropping of legumes and grains (not only one year after the other but instead at the same time at the same place): Legumes deliver nitrogen and the grain is the plant for the legume to creep.
- Instead of aritificial and costly fertilizer Bacteria (Diazotrophs, usually living in symbiosis with legumes) can do the work - even better, because plant and Bacteria (in symbiosis)are living together in symbiosis. Bacteria delivers nitrogen and the plant delivers carbohydrate (starch/sugar). Even better is the combination of these Bacteria with a special flavonoid (plant pigment) called naringenin (especially in tomatoes; e.g. in tomato puree or tomato paste). With this substance legumes are signaling in a chemical matter that they are needing nitrogen in exchange for delivering starch or sugar. The colonization of the roots of the legumes (or here: of the crops) is enhanced through the application of naringenin.
The enhancement of the growth of the plants is not only better because of the nitrogen but because of different substances which are produced through this symbiosis.
Here is a study which analyzed this effect at Brassica napus (rape, canola):
"Effects of Glucosinolates and Flavonoids on Colonization of the Roots of Brassica napus by Azorhizobium caulinodans ORS571"
http://aem.asm.org/cgi/content/full/66/5/2185
One firm (i am too lazy in the moment to find similar products with a description in english; i get no money or any advantage from this firm. It's just my private struggle against misinformation and agrimultis like pioneer, Cargill, ADM, Monsanto, Bayer Crop Science, Syngenta, et.al.) where you can buy this ecological (!) sort of fertilizer (there should be more, which are selling suitable Bacteria):
"Phylazonit
link The price is 57 Euro (ca. 92 Dollar) plus shipment for one kilo (needed for an area of about one hectare) of powder. You have to mix it with water. It's quite expensive for the owner of a small garden, but perhaps you can convince your neighbours AND: If you are cultivating your garden in a ecological way (no articificial fertilizers, no insecticides, herbicides, etc.) then you only have to buy and apply it perhaps once in your lifetime, because then you don't kill your tiny little friends and they are happy in your soil till the end.