【摘要】 研究表明,吸氮量是反映土壤供氮能力最灵敏、最稳定的生物指标,也是评价各种土壤有效氮测定结果与实际符合程度的客观标准,而产量、生物产量、相对产量、增产(长)率、增产(长)量等项指标在反映土壤供氮能力方面效果依次下降,且均逊于吸氮量。以施磷情况下的生物指标作为判断土壤有效氮测定方法效果的标准,更为可靠。更多还原

【Abstract】 Field experiments show that the amounts of plant uptake nitrogen. is the most sensitive andstable biological index in reflecting soil nitrogen-supplying capacities and the objective creteria forevaluating the methods determing available nitrogen. Yields, dry matter, percentages of the yieldswith no N fertilization over the yields with N addition, yield increase percentages and yield in-crease amounts by N fertilization, are not so perfectus nitrogen uptake by plants,the correlationsbetween these indeces and initial soil NO₃^- -N being decreased by the mentioned order. Also, theamounts of plant uptake nitrogen from the treatment with P fertilization are more reliable for judging determined results by different methods.更多还原