The ancient art of multicropping to enhance soil quality

It is known that 80% of the atmosphere consists of nitrogen. All living beings need this nitrogen to produce amino acids and proteïns. But there is only one organism that can actually transform the atmospheric nitrogen into forms of nitrogen we can use as living beings. And that is a bacteria. They connect nitrogen and enable life. 

It is actually the monoculture of crops that impoverishes the soil because the nitrogen in it is exhausted. Ancient people like the Meso-American civilizations discovered that for example adding beans and peas to the maize crop fields helped recharfing the soil. They discovered by 300 BC that planting the alder (els, elzenboom) would fertilize the soil and enable a more intensive growing of other crops as well.

In Europe people discovered that fodder (lifestock) crops like lupine, clover and lucerne (alfalfa) were even more effective to repair the nitrogen level in the soil then beans and peas. 

In China and Vietnam the major nitrogen enhancer was a small water fern called Azolla that lived in symbiosis with a bacteria and worked very well on rice paddies. In the mud in which the rice was grown the azolla was added as a kind of green manure. 

People just knew it worked without further research. Only in the 19th century it was found that it were in fact the weird knobs at the end of the roots of the supporting plants like pulses that were holding the nitrogen connecting bacteria. 

To keep on feeding the growing world population, researchers and governments started to look for more ways to add nitrogen in the soil. Once the natural reserve was exhausted (mainly in South-America) we started to develop synthetic manure. Now we face the waste of tonnes of synthetic products in our rivers, seas and lakes, disturbing completely the nitrogen cycle. 

Not all regions in the world have been touched by this development. In India we found out that higher regions like Uttarakhand, Assam, Sikkim have used little or even no synthetics on their fields, mostly because farmers could not afford to buy them (see earlier Adya post on Sikkim state).

So at a certain point we decided to add artificial products to be able to keep up with what the growing earth population needed. At the same time we disturbed the eco-system in a great number of regions. 

Let us support the people and organizations that keep on looking for better ways to keep a certain level of production while respecting our soil and natural ways of enhancing its quality.

(ref. Oaxaca Journal, Oliver Sacks, 2002)