MICHAEL BÖHME, ANH LE HUNG
Humboldt-Universität zu Berlin, Department of Horticultural Sciences, Germany
The agriculture in Vietnam is characterised by an intensive monoculture in the arable land. This is the reason why in many regions decrease the soil fertility. To improve the soil fertility and quality more organic fertilisation as composts are necessary. In the first stage of the investigations the circuit of organic wastes and their different use in rural and urban areas of Vietnam was analysed. In the second stage experiments were carried out to clarify possibilities for utilisation of different biomass especially in rural areas. Investigations of the sources of unused biomass in the suburban and rural area showed sufficient organic waste materials as residues from harvesting or as residues from the processing in the industry. A large amount of these waste materials are burned for cooking in the households of the farmers. There are no investigations whether materials with high content of cellulose as sugar cane bagasse, sugar cane leaves, banana leaves or wood shavings can composted in a short time in good quality. It is known such materials with high cellulose content can compost only by use of special methods to accelerate the microbiologically decomposition. In the experiments the influence of different microorganism was investigated, adding of supplements and different humidity on composting process of the named materials. The aim of the experiments with composting was to get high quality compost suitable for cultivation of Vietnamese vegetables. For composting process of sugar cane bagasse and banana leaves normally more then 3 month are necessary. In the experiments were clarified that certain microorganism in a good calculated quantity have an important influence on the compost process. Using such composting methods in a period of 5 weeks compost with high quality was produced. Vegetable plants cultivated in this compost had better results in comparison with standard formulations. Resulting of these investigations and experiments composting method is developed appropriate for the conditions in humid tropical regions as Vietnam. Recommendations were elaborate for optimal exploitation of waste biomass in Vietnam in result of numerous experiments with composting.
Keywords: Compost quality, composting, organic fertilisation, sugar cane, waste material