Restoring the Soil - Canadian Foodgrains Bank

Decision Tree Guide51the nitrogen and organic matter are burned off or eaten by animals, so farmersrarely use them for the purpose of fertilizing the soil. This means they are notgm/cc systems by our definition. Nevertheless, these crops can be used to fertilizethe soil somewhat, especially where dispersed shade is used, dry seasons are shortor animals are absent.If either of these species is used, dispersed shade and perhaps other gm/ccs shouldalso be used in order to achieve a noticeable improvement in soil fertility. If youare working below 800 m in elevation, go to #24. Additional ways of fertilizingthe soil should also be used. Go to #41.41. Major crop. What is the major subsistence crop in the local farming system?a) If the main subsistence crops are maize, sorghum or millet, go to #42.b) If the main subsistence crop is rice, go to #46.c) If the main subsistence crops are vegetables, a root crop or a perennial,go to #50.d) If a lot of the area’s land has no crops because it has been turned intowasteland, go to #60.42. Maize, sorghum and/or millet are the main crops. Are many of the maize,sorghum or millet fields free of intercropped species? If not, go to #43. If so,go to #49.43. All fields are intercropped. First of all, it is important to make sure this is actuallythe case. Observation of the fields will be more reliable than asking people. Inmany areas of the world, people feel they should intercrop all their fields, andtherefore claim they do. If a significant portion of fields are not intercropped,see #49 also. Where all the fields are, in fact, intercropped, the best approach isusually to plant the gm/ccs in a hedgerow or (if the rains permit) use them in adry-season rotation. Both these systems are usually a little less popular than mostother gm/cc systems, but they have been successful and sustainable in many areas.If farmers prefer a dry season rotation, go to #44. If they prefer hedgerows, go to#45.44. Dry season rotations. Grain legumes can often be relayed into maize, sorghum ormillet crops (if the intercrops are harvested before the maize), or planted after themain crops at the beginning of the dry season (Photo 28). The limiting factorshere will be the length of the wet season, how much moisture is retained in thesoil and whether or not at least some rain falls during the “dry” season. Dry seasonrotations are usually used in areas where the total annual rainfall is well over1,000 mm, although S20, the maize/wild sunflower (Tithonia diversifolia) system,is used in a droughty area that receives an average of much less than 1,000 mm.For dry season rotations that are used with maize and its intercrops, you couldchoose S14, S20, S69, S70, S71 or S75, and then go to #5.S50 and S51 can also be used in the same sort of situation, even though they are