【摘要】 探讨一种较简便的生物方法来正确地反映不同肥料和土壤在淹水条件下的供氮规律和特点。以蕹菜为指示作物进行连续种植分期刈割测定,并结合Logistic方程进行分析。结果表明,这个方法节约了工作量并增加了取样次数,获得的氮素动态图精确性高,也符合田间实际情况。 文章讨论了Logistic曲线方程描述的土壤和不同肥料的供氮过程和供氮强度的特点。试验土壤为江苏省无锡黄泥土,肥力较高,土壤氮素释放速度在供氮强度高峰期以前呈直线上升,以后则急剧下降并趋于平稳。化肥和绿肥的氮素有效度差异显著,供氮过程表现也迥然不同;他们对于土壤N的“激发效应”在供氮强度高峰期以前很相似,而以后则有明显的差别。最后讨论二种肥料¹⁵N在土壤中的动态。更多还原

【Abstract】 The object of this study is to seek a simple and convenient biological method to properly evaluate the nitrogen supplying patterns and characteristics of the soil and different fertilizers under submerged condition.Used as an indicater crop, Wengcai （Ipomoca Aquatica Forsk） was continuously cropped and samples were taken at different stages by cutting for analyses. The data were treated by means of logistic equation. The results indicated that the continuously cropping method made it possible to increase the number of sampiing without an increase in the amount of work and gave a good picture of the dynamic nature of the nitrogen stpplying pattern under submerged condition.The results obtained from the pot experiment conformed with the actual field condition.The logistic curve equation was discussed in connection with the nitrogen supplying processes and intensities of the soil and different nitrogen fertilizers.The paddy soil used in this study was taken from Suzhou Prefacture, Jiangsu Province. The native fertility was high. The rate of nitrogen liberation was linearly increased before the peak of N supplying intensity, then rapidly declined and finally became smooth and steady. There was great difference between the N availability of chemical fertilizer and that of green manure, their N supplying processes being distinctly different. The "priming effect" of chemical fertilizer and that of green manure on soil nitrogen were similar before the peak of N supplying intensity but quite different after that. Finally the dynamic nature of the two fertilizers tagged with ¹⁵N in the soil was discussed.更多还原