Rice is the most important crop in Mekong Delta. The high yielding rice varieties and the rice cultivation cause large quantities of rice residues  after harvest as straw, rice are still available on the field. Most of rice straw was burnt or removed after harvesting prepare for the next crop. Burning straw for rice intensive culture is leading the air pollution may a cause of soil quality reduction in long term. This study therefore aims to find a potential and promising solution through the composting process under the efficiency of bio products. The experiments consisted five treatment: rice straws (control treatment), rice straw treated with Biomix, Emic, Trichoderma and biogas effluent. Research results showed at 70 days, the straw of five treatment were completely decomposed. The environmental factors affect on the rice straw in composting process with the different bio products through descending temperatures, increasing carbon content and decreasing C/N ration each the stable values. Decomposing rate of the straws with Biomix treatment and the straws with biogas effluent were similar and faster than control treatment. The straws with Emic have been decomposed for a long time and less nutrients contents than other treatments cause of low moisture in composer. In the treatment of straw with Trichoderma has the fastest composing time and highest nutrients contain 30.28% C/N ratio, 1.24% total nitrogen (TN), 0.95% total phosphorus (TP).

Keywords: bigas effluent, biomix, composting process, emix, rice straw, trichoderma.