Soil conditions,vegetation structure and biomass of a Javanese homegarden

The soil of a west Javanese homegarden was a clay-loam, humic Cambisol of medium fertility, with neutral to weak acid reaction. The 0.13 ha large garden contained about 60 plants species (excluding weeds), of which 39 supplied useful products and the remaining were ornamentals. Tree coverage was 81% and total ground cover, including ground litter and weeds was 99%. The vegetation was multi-layered. Total biomass was estimated to 126 t ha^–1, including 4.4 t ha^–1 of ground litter. Of the total biomass, 95% belonged to the tree compartment;Cocos nucifera, Eugenia aromatica andLansium domesticum alone constituted 75%.The homegarden resembled young secondary forest both in structure and biomass, and may be considered as a man made forest kept in a permanent early successional state. The nutrient pool stored in the vegetation was generally low compared to the soil reserves. Only the pool sizes of N and K constituted a significant percentage (5.5 and 11.7%, respectively) of soil reserves.It is concluded that the sustainability of the homegarden is connected to the medium fertile soil with large nutrient reserves, the large plant biomass directly and indirectly protecting the soil against erosion and drying, and a high species diversity providing a large variation in crop phenology and stability in nutritional supply. All this is in contrast to what has been experienced in most attempts of practising monoculture on sloping lands on Java.