00994nam a22001697a 450000500170000000800410001702000140005805000160007210000220008824500550011025000120016526000380017730000460021550000200026150504850028165000580076620210414114124.0120822t        xxu||||| |||| 00| 0 eng d  a198594828  aS604.37.R87  aRuthenberg, Hans.  aFarming systems in the tropics. /cHans Ruthenberg  a3rd ed.  aU.S.A. :bClarendon Press,c1980.  axiv, 313 p. :bill. (part col.) :c24 cm.  aIncludes index.  aContents: Introduction -- Some characteristics of farming in a tropical environment -- Shifting cultivation systems -- Fallow systems -- Ley systems and diary systems -- Systems with permanent upland cultivation -- Systems with  perenial crops -- Grazing systems --Systems with arable irrigation farming -- Systems with parenial crops -- Grazing systems -- Tendencies in the development of tropical farming systems -- Notes on methodology in cropping and farming system research.   aAgricultural systems -- Tropics x Farm management