Restoring the Soil - Canadian Foodgrains Bank

Decision Tree Guide39hardy that the biggest worry for years with respect to this species was that it wasdifficult to eliminate. One method to remove this species from a field is by pruningit down to the soil surface at the beginning of the dry season. If you selectthis system (described in S7), proceed to #5.15. Potatoes. Tarwi (Lupinus mutabilis) can be used at these altitudes (Photo 14).Tarwi is used in a number of ways to fertilize white potatoes in the Andean countries.Tarwi produces a traditional, still widely-consumed edible bean, although itmust be washed and cooked before consumed. Tarwi is an erect plant that reachesabout 1.5 m in height. It is also one of the best legumes in the world in terms offixing nitrogen and produces up to 400 kg N/ha. Choose between systems S32,S33, S34 and S35, and then go to #5.16. Fruit trees. See information on tarwi in #19. See S40 and then go to #5.17. Area’s main crop? What is the main crop in the area? If maize, go to #18. Ifwhite potatoes, go to #19. If fruit trees, go to #20. If it is various other annualcrops, go to #21.18. Gm/ccs for medium-altitude maize. Both fava beans (Vicia faba) (Photo 18) andrunner beans (Phaseolus coccineus) are commonly intercropped with maize. (Seedescriptions of these in #14.) If the farmers prefer fava beans, use S6 and go to#5. If they would prefer runner beans, use S13 and go to #5.19. Potatoes. Tarwi (see #15) can be planted with potatoes in a variety of ways. Iffarmers prefer to use tarwi in a rotation with potatoes, choose S32. If they preferto grow it along the borders of their potato fields, use S33. If they choose tointercrop it among their potatoes, use S34. In each case, return to #5.If farmers would prefer to grow fava beans (described in #14) with their potatoes,see S35, and go to #5.20. Fruit trees. Select S40, and then go to #5.21. Other crops. Consider S40 and S63. If you decide in favor of either, go to #5.22. Below 800 m? If the region is between 800 m and 1,500 m in elevation, or in atemperate zone, go to #27. If within the tropics and below 800 m in elevation,consider using dispersed shade along with the low-stature gm/ccs. Go to #23.23. Dispersed shade. Dispersed shade refers to a light tree cover (about 15% to 20%shade) that is maintained over a field in the lowland tropics. In these areas, themid-day heat is so intense that all unshaded crops stop growing for two or threehours in the middle of the day. A light shade will create a favorable microenvironmentthat can increase crop yields by about 40%. Scientific experimentshave shown that 15% shade will also increase the growing period of crops by at