四种生物覆盖植物的自然分解及养分释放动态

Decomposition and nutrient release of four mulching plants in the upland area of Guizhou Province

利用网袋法对白栎、马桑、白茅和蕨等4种生物覆盖植物的自然分解和养分释放动态进行了研究。结果表明:植物种类不同,其水分、氮、磷、钾含量存在差异,其中以白栎叶中氮、磷含量和白茅钾含量最高,分别达28.50、1.77和15.91g/kg,而马桑嫩枝中含水量较高为82.70%。在2年的自然分解过程中,白栎、白茅、蕨和马桑的分解速率分别为96.61%、100%、96.49%和100%,以生长季节月分解速率较高,非生长季节时较低。覆盖植物前期分解较快,后期分解较慢。半衰期以白栎最小为50d,马桑最大为300d。白栎残留物中的含氮量较高,白茅残留物中含磷量较高,分别为17.22和0.83g/kg,蕨残留物中的含钾量较高为4.71g/kg,马桑的氮、磷、钾含量稳定性较高。

The natural decomposition and nutrient release of four mulching plants were studied using nylon litterbag method from 2004 to 2005, and the two-year results were as follows ： There were some differences in the content of nitregen, phosphate, potassium and water among four mulching plants. The highest nitrogen and phosphate contents were observed in the leaves of Quercusfabri, reaching 28.50 and 1.77 g/kg respectively, while the highest potassium and water contents were measured in Imperata cylindrical var. major （15.91g/kg） and in the young branch of Coriaria nepalensis （82.70%）. During the decomposition of 2-year period, decomposition rates of Q. fabri, 1. cylindrical, P. aquilinum and C. nepalensis were 96.61% , 100% , 96.49% and 100 % , respectively. However, the decomposition rate was higher in growing season than in non-growing season, as well as higher in early stage than in late stage. The half-life of Q. fabri was 50-day, which is the smallest among four mulching plants, while the biggest half-life was observed in C. nepalensis, reaching 300-day. The nitrogen-residue of Q.fabri was the highest among four mulching plants, reaching 17.22 g/kg, while phosphate-residue of 1. cylindrical and potassium-residue of P. aquilinum were the highest, reaching O. 83 g/kg and 4.71 g/kg respectively. The stability of nitrogen, phosphate, potassium content in C. nepalensis was the highest among four mulching plants.