The double-cropping rice is known as the principal type of cultivated rice in the suburbs of Shanghai.In comparison with them late-maturing single-cropping rice,the former is fundamentally characterized by its short growing period.as well as its appearance of panicle primordial differentiation in tillering stage,thereby giving rise to an outstanding peek of nutrient up take within 2 or 3 weeks after transplantation.During this period,there is an drastic increase in both the concentration of the nutrient content and the quantity of daily absorption of the plant above the ground.ht is estimated that during a period of three weeks after transplantation,the nitrogen ahsorption amounts up to 60-70% of its grand total throughout the whole growth period.In the peak uptake stage,the nitrogen percentage of the plant is significantly correlated with the number of ripening grains,available ears and grain production.