不同种植年限白沙蒿对根际土壤营养元素的影响

分别选取建植5、10、15和20年的白沙蒿(Artemisia sphaerocephala), 研究其根际与非根际土壤中营养元素含量及土壤pH值的变化。结果表明, 1)随建植年限的增加, 白沙蒿根际土壤有效N、P含量增加, 铵态氮和有效磷的最大富集率分别为91.15%和127.30%;2)有效Cu表现为负富集, 其在根际的含量随建植年限的增加而降低, 其它有效微量元素均表现出根际含量大于非根际, 其中有效Mn随年份增加有明显积累, 在20年株龄富集率达到最高值, 85.24%;3)5、10年株龄沙蒿根际pH无明显变化, 15、20年株龄白沙蒿根际土壤表现出明显的酸化作用;4)土壤有效元素间的相关性存在明显的根际效应。

Effects of different ages Artemisia sphaerocephala on the content of nutrient elements in rhizosphere soil

The variation of nutrient elements contents and pH value between rhizosphere and non-rhizosphere soils of 5, 10, 15, and 20-year-old Artemisia sphaerocephala were studied. The results revealed the following conclusions: 1) With the extension of growing period, N and P in rhizosphere soil increased, the highest enrichment rate of ammonium and P were 91.15% and 127.30%, respectively. 2) Cu had negative enrichment, which decreased with the extension of growing period. The contents of other micronutrients were higher in rhizosphere than that in bulk soils. For example, Mn accumulated significantly in rhizosphere with the extension of growing period, and the highest enrichment rate 85.24% which appeared in 20 year-old A.sphaerocephala growing soil. 3) There were obvious acidification in rhizosphere of 15 and 20 year-old A.sphaerocephala, however, there was no obvious change in rhizosphere of 5 and 10 year-old A.sphaerocephala. 4) There was rhizosphere effects correlated with different nutrient elements in soil.