水稻耐肥性与氮肥施用量的研究

根据羣众“因土种植,看苗施肥”的经验,在肥力高的土壤上,选用耐肥强的品种,而在肥力低的土壤上,则选用耐肥弱的品种,前者施肥量高,后者施肥量低。农民这种传统的栽培习惯对我国农业生产获得大面积较好的收成起了很大作用。

STUDIES ON THE ENDURANCE FOR HEAVY NITROGEN APPLICATION OF EARLY RICE

Three varieties of early rice, namely Dwarf-Nanta, Lo-tsai and 503 were studied for their endurance at various rate of application of ammonium sulphate. Their root characteristics and leaf composition were analysed. Positive correlations have been found between the endurance of rice plants to heavy nitrogen fertilizer and the absorption surface and ration exchangeable capacity of their roots. The order of stability of the three varieties of rice at heavy nitrogen application is Dwarf-Nanta>Lo-tsai>503. Dwarf-Nanta showed a slight increase of silica in leaves with an increased rate of nitrogen supply. On the contrary, the content of silica in leaves decreased with increasing supply of nitrogen in Lo-tsai and 503. Under high nitrogen application, the contents of protein-N and chlorophyll in the leaves of Dwarf-Nanta, presumably due to its strong nitrogen assimilation power, also appeared higher than the other two varieties.