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.