摘要： 采用¹⁵N示踪和模拟土柱技术,对不同透水性土壤施用氮肥后水稻生育和氮肥利用率进行了研究。结果表明:土壤透水速率以20～30mm/d对水稻生育最为有利,完全不渗漏和透水速率超过40mm/d时,水稻分蘖明显减少,收获期干物质积累和子实产量仅为适宜透水率时的66.7%～93.4%和65.2%～93.8%。土壤透水性强烈影响水稻对氮肥的利用效率。土壤透水率在20～30mm/d时,水稻对氮的利用率超过60%,而不透水土壤和严重渗漏土壤的水稻对氮肥利用率仅为32.6%～44.1%,损失率达30.8%～46.0%。稻作期间田面水层和0～5cm土层pH与土壤透水率呈负相关,排水不良易引起氨挥发。日渗漏20～30mm可作为沿黄高产稻麦田培育的定量指标。

关键词: 沿黄稻麦轮作区, 水稻, 15N示踪技术, 氮肥利用率, 土壤透水性

Abstract: The rice gro wth s tatus and utilization ratio of ni trogen fertilizer under the condi tion of dif ferent soil perme ability in the nethouse were inves tigated by ¹⁵N tracer and imi tat ive soil c olumn technique.The resul ts showed that the soi lwi th 20～30 mm/ d of the leakage speed was of most favorable to rice growth. When the soil permeabi li ty was over 40mm/ d or 0 mm/ d, the numbers of rice effective ti llering decreased obviously, and the biological and economical yield at harvest period were 66. 7% ～93. 4% and 65. 2%～ 93. 8% of the treatment in comparing wi th the optimum soi l permeabi li ty, respectively.The util ization rat io of ni trogen fertil izer exceeded 60% when rice was planted in the soil with opt-imum permeabil ity, but i t was only 32. 6%～44. 1% when planted in the other soil and the N loss reached 30. 8% ～46
0%. The pH of surface soi l (0 ～5 cm) and surface water was negat ively correlated wi th soil permeability. Poordrainage was easy to resul t in more N los s by NO₃ volati lizat ion. 20～30mm/ d of soil leakage speed could be considered as an quanti tative inde x for high yield soil along the Yel low River.

Key words: Rice and wheat rotation, Rice¹⁵N trace technique, Utilization ratio of N fertilizer, Soil permeability

中图分类号: 

• S511