[Primary study on absorption, translocation and accumulation of N, P and K of Achyranthes bidentata].

Objective: To study the absorption,translocation and accumulation of N,P and K on Achyranthes bidentata.Method: The contents of N,P and K were determined by mean of sulfuric acid-hydrogen peroxide assimilating method,vanadium-ammonium molybdate colorimetric method and flame photometric method,respectively.Result: The contents of N,P and K in the plant were decreasing during the growth period.The absorption rates of the three nutrients by A.Bidentata showed double-peak curves in the whole growth period,maximum absorption rate appeared in the middle ten days of October.About 8.59 kg of N,1.36 kg of P and 7.40 kg of K were needed to produce each 100 kg root.Conclusion: The key nutrients absorption period is in the first ten days of September and in the middle ten days of October.