EFFECTS OF EXOGENOUS NITROGEN FORMS ON RICE GROWTH AND NITROGEN ACCUMULATION

In order to optimize the concentration ratio of different forms of nitrogen and improve the effect of foliar fertilization, the effects of different concentration ratios of exogenous glycine nitrogen, nitrate nitrogen and ammonium nitrogen on biomass, nitrogen content, root morphology and leaf physicochemical indexes of rice were investigated. The results indicated that the effects of different exogenous nitrogen concentration compositions on the biomass, nitrogen content and physiological and biochemical indexes of rice were significantly different (p<0.05) when they were applied at the tillering stage of rice. The highest biomass and nitrogen content of rice were 68.6 mg center dot p(-1) and 1888.5 mg center dot g(-1) respectively, under the treatment of high glycine nitrogen (2500 mu mol<middle dot>L-1), ammonium nitrogen (2500 mu mol<middle dot>L-1) and low nitrate nitrogen (2500 mu mol<middle dot>L-1). The changes of total root length, root surface area, root volume and root activity were consistent with those of biomass. The highest contents of chlorophyll, soluble protein, soluble sugar and SOD activity were 7.35mg/g, 39.25mg/g, 38.81mg/g and 342.56 U<middle dot>g-1 in high glycine-nitrogen and low inorganic nitrogen treatment, respectively. A certain increase of Gly-N concentration and reduction of inorganic nitrogen concentration can contribute to the growth of rice.