[Effect of chlorpyrifos residue in red soil on crops].
The pot cultivation experiment method, integrating with laboratory analysis, was employed for exploring the influence of chlorpyrifos residue in red soil on growth of wheat and oil-seed rape seedlings, and the uptake of crops to chlorpyrifos residue. The results show that, wheat seedlings and oil-seed rape seedlings can absorb chlorpyrifos residue from soil to reach the concentration of 0.257 to approximately 4.50 microg/g and 0.249 to approximately 2.021 microg/g, respectively, 20 days later since chlorpyrifos was introduced into the pots, on condition that the initial concentration of chlorpyrifos residue in red soil was 1 to approximately 10 microg/g. The initial concentration of chlorpyrifos residue in red soil equivalent to or below 10 micro/g has not significant influence on growth of wheat seedlings. Similarly, the concentration equivalent to or below 5 microg/g has not significant influence on growth of oil-seed rape seedlings. The degradation rate in oil-seed rape rhizosphere soil is 1.4 to approximately 4.2 times more than in that in unvegetated soil. The amount of bacterium and fungus in oil-seed rape rhizosphere is 3.18 times and 1.84 times as much as these in unvegetated soil, respectively. However, there is no substantial difference of actinomyces between in rhizosphere soil and in unvegetated soil. Compared with unvegetated soil, pH in rhizosphere soil is lowered by 0. 19 to approximately 0.23.
Wang
Li-gang
LG
Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. lgwang0827@yahoo.com.cn
Jiang
Xin
X
Yan
Dong-Yun
DY
Wang
Fang
F
Bian
Yong-rong
YR
Wu
Jin-shui
JS
Li
Xin-ai
XA