Mulching effects and the soil organic matter dynamics in crushed bamboo utilization at the farmland

The objective of this research was to evaluate the effect of covering the soil surface with the crushed bamboo and to simulate the soil organic matter dynamics after the crushed bamboo was put into the soil at farmland. The first experiments in the phytotron (25 °C, 70%) showed that covering the soil with the 2 cm and 4 cm thick crushed bamboo prevented the decrease of the soil water content as well as vinyl mulching, and reduced the total amount of the irrigated water 20% less than no mulching. In addition, the crushed bamboo mulching kept the soil temperature lower than the others and made the electrical conductivity in the soil high just after irrigation. The second experiment showed that the crushed bamboo mulching applied the potassium to the crown daises so that the potassium content of the crown daises increased. Finally, the soil organic matter dynamics was simulated with the CENTURY model. It was predicted that if the 2 cm thick crushed bamboo was put into the soil, the most was decomposed in 20 years, and when it was put into the soil every year, the total amount of the soil organic carbon increased 7000 g/m² in 20 years, which made the C: N ratio keep 20. In this simulation, it seemed that the crushed bamboo of which thickness was less than 2 cm can be applied.