from: NASA APOD
1 min. 59 sec.
"Milpa crops are nutritionally and environmentally complimentary. Maize lacks digestible niacin, the amino acids lysine and tryptophan, necessary to make proteins and diets with too much maize can lead to protein deficiency and pellagra, a disease caused by lack of niacin. Beans have both lysine and tryptophan, but not the amino acids cysteine and methionine, which are provided by maize. As a result, beans and maize make a nutritionally complete meal. Squashes, for their part, provide an array of vitamins; avocadoes fats."Milpa has other effects too. While maize takes out nitrogen from the soil, the beans make it available, thus ensuring that the soil is not too depleted and can be used for future cultivation. Maize, which is grown first, provides the shoots which the vines of bean use as support to ascend. Meanwhile, the low-growing squash reduces the possibility of weeds gaining sunlight, and by covering the ground it keeps the soil from becoming dry. Thus the three as a team achieve what each crop individually might not have been able to on its own.
‘The back-and-forth among farmer, chef and market customer means more variety.’