Restoring the Soil - Canadian Foodgrains Bank

68Green Manure/Cover Crop SystemsAfrican Green Manure/Cover Crop SystemsBurkina FasoS50 and S51. Millet and sorghum/nyama-1. Nyama (Piliostigma reticulatum) is aperennial bush native to the Sahel (see #45 for information on nyama). In this system,nyama leaves are carried from the bush to fertilize millet and sorghum in northeasternBurkina Faso. We know that at least hundreds of farmers use this traditional system.S52. Millet/nyama-2. Nyama is allowed to volunteer in farmers’ fields. Just before therains come, it is pruned down at ground level and the leaves are spread across the fieldto fertilize it. This traditional practice is used by thousands of farmers in both BurkinaFaso and Mali.GhanaS53. Maize/mucuna-9. This system is a simple rainy season intercrop of mucuna inmaize. The mucuna is intercropped late enough in the maize’s growing season so themaize is not overcome by the mucuna. In one area, the people were actually usingthe variety of mucuna that provokes severe itching, meaning they couldn’t go neartheir fields for two months. They switched to the non-itchy mucuna immediatelyafter learning about it. Thousands of farmers use this traditional system. In addition,thousands—if not tens of thousands—use the same system in Benin and Oaxaca Statein Mexico.S54. Maize/nyama. At the end of the fallow period, when the fields are to be burned,the nyama bushes are cut and covered with dirt, so that less nitrogen will be burnedoff. Actually, this system was used traditionally for all local crops, but is disappearingas fallowing itself is disappearing in the Sahel. Quite likely almost no one is using thistraditional system today.S55. Maize/calopogonium. Calopogonium (Calopogonium mucunoides) is used inrotation with maize in parts of Ghana and neighboring countries. There are probablythousands of adopters. This system started being used after calopogonium was introducedinto the country. To the dismay of many farmers, calopogonium has become anoxious weed. This system is not recommended for use anywhere else.S56. Maize/leucaena. In another interesting system, Leucaena leucocephala is intercropped(three seeds per square metre) in maize and allowed to grow the whole rainyseason. After the maize harvest, the field is burned lightly to kill the leucaena withoutburning away all the nitrogen. This is done in Benin (where the practice originatedand where it is apparently widely practiced) and southern Ghana, where perhaps a fewhundred farmers use it.