[Effects of earthworm (Eisennia foetida ) on As, P uptake by maize and As, P fractional transformation in the rhizosphere].
A pot experiment was conducted to examine the roles of earthworm in As uptake from original As-polluted soil by maize (Zea mays L.), and their effects on As, P fractions in the rhizosphere. The As-polluted soils with three As levels were collected from the arable soil near As mine. The plants were harvested after 10 weeks of growth. Dry weight (DW) and P, As concentrations of plants, as well as As and P fractions of the rhizospheric soil, were determined. The results showed that inoculated earthworm or appended rice straw increased maximal 149%, 222% DW of root and shoot, respectively. At the medium and high soil As levels, root As concentration in the soil treated by earthworm and rice straw was highest among all treatments, and earthworm increased more As concentration of shoot than rice straw did. In different soil As levels, root P concentration in the soil treated by earthworm was highest, and shoot P by rice straw. Ca-P affected maize absorbing As at the low soil As level(r = 0.981), and maize absorbing Al-P was restrained by As involved in well-crystallized hydrous oxides of Fe and Al at the medium (r = 0.953)and high (r = 0.997)soil As levels. The concentration of non-specially absorbed As and As combined with Fe or Al and of O-P increased at the soil inoculated earthworm or/and appended rice straw at the same time. These results indicated that earthworm was more valuable for plant developing than rice straw was.
Bai
Jian-feng
JF
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. bjfwjp@126.com
Lin
Xian-gui
XG
Yin
Rui
R
Zhang
Hua-yong
HY
Wang
Jun-hua
JH
Chen
Xue-min
XM
Li
Jiang-yuan
JY
D000818:Animals; D001151:Arsenic / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D005591:Chemical Fractionation; D017753:Ecosystem; D009835:Oligochaeta / Q000378:metabolism*; D010758:Phosphorus / Q000737:chemistry / Q000378:metabolism*; D018517:Plant Roots / Q000254:growth & development / Q000378:metabolism*; D003313:Zea mays / Q000254:growth & development / Q000378:metabolism*
D010758:Phosphorus; D001151:Arsenic