Study on dynamic change of middle and micro element in Panax notoginseng plant soils with different interval year

OBJECTIVE: To study effects of different interval year on Panax notoginseng plant soils middle and micro element content. METHOD: The dynamic change of Ca, Mg, Mn, Cu, Zn, B from Mabai, Matang, Gumu and Panlong were determined under different planting patterns (new soil, interval 5 years soil and continuous cropping soil). RESULT: All the micro elements (except Ca, Mg) of interval 5 years soil and continuous cropping soil were significantly higher than those of new soil. All the middle and micro elements (except B) of interval 5 years soil were significantly higher than those of the continuous cropping soil. Planting patterns had remarkable influence on the content of Mn, Cu, B, but not Zn Ca, Mg. Cu, Ca under the 3 planting patterns, and Zn under the continuous cropping pattern did not show significant quarter changes. B content increased with the elongation of implantation time. Zn in new soil and interval 5 years also increased with prolonging of planted time. Mg, Mn and Cu content reached to peak value on April next year, and reached to minimum on the end of this experiment. Compared with new soil, the proportion of Mn, Cu in total elements increased by 29%, 114%, Mg, B decreased by 18%, 38%, Zn and Ca changed slightly of interval 5 years soils; In continuous cropping soil, Mn, Cu and B increased by 50%, 120%, 22%, respectively, but Zn, Ca, Mg had no significant change. CONCLUSION: Continuous cropping pattern could not induce the deficient of soil middle and micro elements, and thereafter might not result in continuous cropping obstacles. But the imbalance proportional of soil middle and micro elements in P. notoginseng plant soils may be one of the main reasons for continuous cropping obstacles.