生态沟渠中4种水生植物的氮磷积累效应

Nitrogen and Phosphorus Accumulation in Macrophytes in Ecological Ditch

为探明水生植物的氮磷积累规律,以贵州某生态沟渠中4种优势水生植物(菖蒲、黄菖蒲、水葱、美人蕉)为试验对象,研究各植物生物量及不同器官氮、磷积累量的变化。结果表明:随着生长时期的推进,4种植物生物量逐渐增加,尤其是夏季过后地上部生物量增加明显,秋季达最大值,至冬季后又逐步降低。4种植物总氮、总磷含量差异明显,菖蒲总氮与总磷含量最高,分别为41.26g/kg和11.22g/kg,美人蕉最低,分别为21.22g/kg和7.14g/kg;随着时间的推移,4种植物的地上部分(茎叶)和地下部分(根)氮、磷积累量均逐步增加,至秋季达最大值;10月是多数水生植物生物量和体内氮、磷含量最高的时段,可通过收割去除这部分氮、磷;4种植物中,菖蒲的氮、磷回收量最大(氮10.79kg、磷2.34kg),美人蕉最少(氮0.32kg、磷0.11kg),通过收割4种优势植物,2km河段总共可回收氮22.87kg和磷4.98kg。

In order to reveal the nitrogen and phosphorus accumulation regularity of macrophytes,four dominant hydrophytes,Canna indica,Iris pseudacorus,Scirpus tabernaemontani and Acorus calamus were used for water purification in ecological ditch.The accumulation amounts of biomass,N and P in different organs of the above mentioned plants were analyzed around a year.Results：With the development of growth period,four kinds of plant biomass increased gradually,especially aboveground biomass increased significantly over the summer,and in autumn reached the maximum,then gradually reduced in winter.A wide range of TN and TP contents existed in different plants,with the highest TN content of41.26g/kg and the highest TP content of 11.22g/kg in A.calamus.Besides,The lowest TN content of21.22g/kg and the lowest TP content of 7.14g/kg in C.indica.With the increasing of N and P accumulation in aboveground parts（stem and leaf）and the underground part（the root）,the N and P accumulation gradually increased,and reached the maximum value in the Autumn. According to accumulation of TN and TP,hydrophytes＇ best harvest time were October.Furthermore,they were the highest in A.calamus（N 10.79 kg,P 2.34kg）and the lowest in C.indica（N 0.32 kg,P0.11kg）,22.87 kg N and 4.98 kg P could be recovered by harvesting the four dominant hydrophytes in the 2km river reach,according to the number and contents of TN and TP.