分类: 相关性 | 最新在前 | 最旧在前


795 条目已找到 (正在显示 1 - 10)
  1. 关键资源 1993-04-01 If the small farm is to be a permanent source of food for its owners, it must be managed in a sound fashion that provides a constant source of nutrients, fuel, construction materials, etc. without damage to the land or its productive capacity. Forage crops are important to the small farm as one...  
  2. 关键资源 2007-01-01 By Dr. F. W. Martin. Published in parts, 1989 and 1994; Revised 1998 and 2007 by ECHO Staff Though nearly all plants are useful in some way, they are not equally valuable. For example, wheat, rice and corn may be considered the most valuable plants in the world based on the vast acreage planted...  
  3. 关键资源 So you want to help people in the tropics. Beautiful! The tropics are waiting for you. No matter what your abilities, you can make life better for others in the tropics. Your concern for the physical and spiritual well-being of people can be translated into fruitful service. Your first asset is...  
  4. Guazuma is a small to medium-sized tree that grows up to 30 m tall. Its leaves form a compact, rounded canopy, remaining green throughout the year except in areas with a long dry season. It is used as a source of fuelwood, shade, and fodder for livestock.  
  5. 关键资源
    2013-01-20 About 98% of agricultural production in the Sudano Sahelian region of West and Central Africa is based on rainfed crops. With a mean annual rainfall of 300 to 800 mm/year, the number of staple crops is very limited. It includes two grain crops: pearl millet (Pennisetum glaucum) for sandy soils...