Effect of nitrogen application rate and fertilizer ratio on nutrition quality and trace-elements contents of rice grain

A field experiment was conducted to study the effects of nitrogen rate and ratio of panicle-spikelet fertilizer(PSFon) amino acids,crude protein and Fe,Zn,Cu,Mn,Mg,Ca contents of rice grain in Xichang city,Sichuan province.The results showed that both amino acids and crude protein contents of rice grain increased along with total(nitrogen) rate and ratio of panicle-spikelet fertilizer increasing.The influence of nitrogen rate and ratio of panicle-spikelet fertilizer on amino acid content varied with the varieties and the kind of amino acids.The effect of nitrogen rate and ratio of panicle-spikelet fertilizer on amino acid content of Japonica variety Hexi 39(HX39) was greater than that of Indica variety Diantun 502(DT502).The effects of nitrogen rate and ratio of panicle-spikelet fertilizer on His,Val,Gly,Pro and Lys contents were greater,while the effects on amino acid Ile,Arg,Asp and Glu contents were smaller.As nitrogen rate increased,the Fe,Zn,Cu,Mn,Mg and Ca content and yield of rice grain rose firstly and then dropped.The optimal nitrogen rate of Japonica variety Hexi 39 for high yield of rice grain,crude protein and high contents of Fe,Zn, Cu,Mn,Mg,Ca was higher than Indica variety Diantun 502.