Abstract: To clarify of the relationship of nitrogen application with dry matter and nutrient accumulation and distribution of fresh-eating sweet potato,the effects of different nitrogen levels on characteristics of dry matter and N,P₂O₅ and K₂O accumulation and distribution of fresh-eating sweet potato have been studied in the pot experiment.The cultivars of fresh-eating sweet potato(LS9 and YS25)were selected as experimental material.The results showed that the accumulation of dry matter and N,P₂O₅,K₂O of YS25 and LS9 shoot were increased with the increase of nitrogen fertilizer application in the same developing stage,while those of YS25 and LS9 root-tuber were increased at first,and then decreased,and their distribution rates of root-tuber were decreased with nitrogen supply.The amounts of nutrients which needed for the formation of 100 kg dried sweet potato of LS9 and YS25 were increased gradually with the increase of amount of N applied,and that was K₂O> N> P₂O₅.In generally,the varieties of LS9 had higher production efficiency of N,P₂O₅,K₂O and dry matter,while YS25 had lower production efficiency of nutrients and dry matter.It showed that LS9 and YS25 had higher and lower physiological use efficiency of the nutrients separately.Responses of production efficiency of nutrients and dry matter of fresh-eating sweet potato (YS25 and LS9) to nitrogen application were almost consistent,namely production efficiency of nutrients and production efficiency of dry matter of N,P₂O₅ and K₂O of sweet potato were decreased by nitrogen application.

Key words: Nitrogen, Fresh-eating sweet potato, Dry matter, Nutrient, Accumulation and distribution

CLC Number: 

• S143.1