【摘要】 本文系利用¹⁵N示踪技术以研究ASU与氮肥配施对杉木苗的效果,氮素利用率及氮素在土壤和苗木间的平衡状况。试验结果表明:ASU标记硫铵配施和单施标记硫铵相比,苗木干物质量由每盆18.51克提高到20.92克,氮素利用率由12.69%提高到16.74%,土壤中残留素由49.73%提高到56.07%。氮素损失量由37.59%降至27.19%,杉木苗吸收之¹⁵N由8.22毫克/盆增至10.85毫克/盆。试验还表明氮肥配施ASU处理的苗木从肥料中吸收的氮素增加（由46.14%提高到52.60%）,面从土壤中吸收的氮索百分率有所下降（由53.86%降至47.40%）。此外,苗木叶绿索的含量也有所提高（每克鲜时叶绿索含量由1.98毫克提高到2.23毫克）。由此可见,杉木苗施用氮肥时配施ASU效果明显。更多还原

【Abstract】 This paper deals with the effects of ASU on the yield of Chinese Fir seedlings grewing on loamy yellow-red earth. The study was carried out on the basis of pot experiment by using tracer isotope ¹⁵N. The utilization ratio of N-element and its state of balance between the soil and the plant were studies as well. The results of our study show: The dry weight of Chinese Fir seedlings treated with N and mixed With ASU is higher than that of untreated with ASU （those treated with N and ASU 20.92 g/pot, with N 18.51 g/pot）. The N-elemenf utilization ratio increased to 16.74% and 12.69% respectively, when caluculation of nitrogen balance indicated that the absorption of N+ASU by the seedlings and the nitrogen residue in soil is higher than that of untreated with ASU, but with respect to the lose, the treat of N is higher than that of N+ASU. The content of Chlorophyll in the seedlings leaves increased from 1.98mg/fresh leaves to 2.23 mg/fresh leaves.更多还原