OBJECTIVETo study the absorption and accumulation of N, P and K in Ophiopgon japonicus.

METHODThe contents of N, P, K and trace element were determined respectively by using the kjeldathl method digested with H2SO4 + H2O2, ammonium vanadstemolybdate chromoscopy, flame spectrometry and atomic absorption spectrophotometry.

RESULTThe contents of N and K were the highest, and that of P was relatively lower O. japonicus. The changing pattern of N was low-high-low in the growth and development period. The accumulative speed of N had two relatively quicker and two relatively slower phases. The content of N is higher in nutritive organs; The changing pattern of P was similar to that of N, while the content of P is higher in leaves and nutritive roots at early stage of growth and development. It was high in root tuber during harvesting stage, and the accumulative quantity in the plant was increased gradually. The level of K was high in early stage and low in later stage of growth. The content of K was relatively higher in leaves and nutritive roots at early stage, and that in root tuber was slightly lower than the leaves but higher than that the nutritive roots from February to March. The accumulating quantity slightly increased in the plant.

CONCLUSIONThe application quantity of N should be increased gradually after transplant, stopped in autumn, and used again in early spring. Phosphate fertilizer is needed in autumn and winter, while large amount of potassium fertilizer shoule be used in winter tine.