生物炭和氧化镁联用对漂浮湿地中氮磷迁移和转化的影响

Effect of combination biochar and magnesium oxide on nitrogen and phosphorus transformation in floating wetland

在种植美人蕉的漂浮湿地中加入0.075%、0.15%和0.3%的氧化镁和10%杏壳生物炭,分析了杏壳炭和氧化镁加入漂浮湿地后基质中氮磷含量、硝化与反硝化强度、美人蕉地上部分和地下部分氮磷含量的变化。结果表明,与未加入生物炭(S)相比,加入0.075%氧化镁的处理(S+M1)美人蕉地上部分氮含量增加达到显著水平(P<0.05),然而加入0.15%(S+M2)和0.3%氧化镁(S+M3)的处理中美人蕉地上部分氮含量下降;相同地,加入氧化镁的处理(S+M1和S+M2)中美人蕉地上部分磷含量均增加。与加入10%生物炭(S+C)相比,加入生物炭和氧化镁后,美人蕉地上部分的氮含量下降,地下部分氮含量增加,另外加入0.075%氧化镁后(S+C+M1)后,美人蕉地上部分磷含量增加78%(P<0.05)。同样地,与处理(S+C)相比,S+C+M1、S+C+M2和S+C+M3处理中基质的氨氮含量下降,S+C+M2处理中基质的总磷含量显著增加(P<0.05)。该结果表明在漂浮湿地中加入少量的氧化镁(0.075%)有利植物地上部分对氮磷的吸收;漂浮湿地中加入生物炭和氧化镁有利于基质对磷的固定。

The 0.075%,0.15%,0.3%magnesium oxide and 9%apricot shell biochar was added into the floating wetland with planting canna to analyze the content of nitrogen and phosphorus,nitrification and denitrification intensity,and nitrogen and phosphorus uptake by canna.The results showed that compared with that without biochar(S),the nitrogen content of above-ground part of Canna increased significantly in the treatment of 0.075%MgO(S+M1)(P<0.05),but it decreased in the treatment with 0.15%(S+M2)and 3%MgO(S+M3).Compared with the addition of 10%biochar(S+C),the nitrogen content of above-ground part of Canna decreased,but the nitrogen content in the under-ground part increased after adding biochar and MgO.In addition,the phosphorus content in the above-ground part of Canna increased by 78%after adding 0.075%MgO(S+C+M1)(P<0.05).Similarly,compared with the treatment(S+C),the contents of ammonia nitrogen and total phosphorus in treatment(S+C+M1,S+C+M2 and S+C+M3)decreased,and the total phosphorus content in treatment(S+C+M2)increased significantly(P<0.05).The results showed that the addition of a small amount of MgO(0.075%)in the floating wetland was beneficial to the absorption of nitrogen and phosphorus by the above-ground part of plants;the addition of biochar and magnesium oxide in the floating wetland was conducive to the fixation of phosphorus by substrate.