不同有机物料在潮棕壤中有机碳分解进程

用尼龙网袋法研究了特定年度中，不同月份间有机物料在潮棕壤旱田、水田中有机碳分解速率及C／N变化。结果表明，4种物料(玉米秸和玉米根，水稻秸和水稻根)在潮棕壤地区温度、湿度适宜的前3个月(1999年7—月)迅速分解，之后进入缓慢分解阶段，其中根的分解残留率始终高于秸秆。经计算约有2／3的玉米根和稻根腐解产物残留在土壤里；分解至试验结束。所有物料的C/N比都趋于一致，约在10—13之间，与土壤腐殖质的洲比非常相近，说明这些物料已基本完成其腐殖化过程，而成为较稳定的有机组分、这对增加土壤有机质、培肥土壤非常重要。

Decomposition process of organic carbon of different organic materials in meadow brown soil

A nylon mesh bags method was conducted in upland and paddy field with meadow brown soil to study the decomposition rate of organic C and the changes of C/N ratio in organic matter during different months of special years. The results showed that four materials (maize stalk and root, rice straw and root) were decomposed quickly during the first three months with due temperature and humidity (July, August and September in 1999), after that was the slow decomposition stage, the residual rate of root was higher than that of stalk. By calculating, about two-thirds decay product of maize root and rice root remained in soil. By the end of the experiment, the C/N ratio of all materials was towards a similar ratio about 10~13. This result indicated that these materials had basically finished humification process and became steady organic components. This was very important to increase soil organic matter and cultivate soil fertility.