ABSTRACT
Rapid decrease in soilfertiligtfollows clearing of forests in the humid tropics and main processes triggered by the removal of vegetation cover are reviewed. The soil of forests, cleared to provide land for cultivation of annual foodcrops are clearly showing a decrease in fertility. This unfortunate phenomena occur mainly in areas of the Indonesian Archipelago located within a belt consisting of areas with 12 months of rainfall and monthly means of 75 and more millimeters. Monocultural cultivation of annual crops in these areas is likely to deplete soil of its fertility and unlessfloodedfield techniques of cultivation is involved, it might seem very unlikely that in the future, the use ofannualfood crops to cultivate clearedforest lands, such as of common practice today, could be maintained without sacrificing soilfertiliiy and destruction. In many parts of theArchipelago, deforestation ofareas to cultivate annual foodcrops is likely to invite processes leading to the fatal destruction of its soil. Unless arboriculture . (tree cultivation), imitating tropical rainforest forests, is practiced to produce food replacing the present traditional production of staple food starch by annual crops, the degradation of the environment will continue ending in an unsustainable, prohtable agriculture. perennial tree likely to become one off the best candidate