中国农业科学 ›› 2009, Vol. 42 ›› Issue (11): 3940-3946 .doi: 10.3864/j.issn.0578-1752.2009.11.022

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

耕层施磷对土壤剖面深层累积NO3--N运移及后效的影响

袁丽金,巨晓棠,刘新宇,张丽娟,王珏

  

  1. (河北农业大学资源与环境学院)

  • 收稿日期:2009-02-12 修回日期:1900-01-01 出版日期:2009-11-10 发布日期:2009-11-10
  • 通讯作者: 张丽娟

Effects of Phosphate Fertilizer Applied to Topsoil on the Movement and Residual Effect of Nitrate Accumulated in Deep Soil Profile

YUAN Li-jin, JU Xiao-tang, LIU Xin-yu, ZHANG Li-juan, WANG Jue
  

  1. (河北农业大学资源与环境学院)

  • Received:2009-02-12 Revised:1900-01-01 Online:2009-11-10 Published:2009-11-10
  • Contact: ZHANG Li-juan

摘要:

【目的】在华北平原,研究前茬小麦耕层施磷对土壤深层累积NO3--N运移及后效的影响。【方法】采用15N微区注射技术,耕层设3个不同的施磷水平,布置田间微区试验,将15N标记于110 cm土层处。【结果】在该试验条件下,小麦收获后标记15N在土壤中的残留量为P60处理<P120处理<P0处理,且发生垂直运移,向上层土壤运移了50 cm,向下移动了70 cm,累积峰出现在120~140 cm土层,较标记位置下移了30 cm。玉米收获后, 15N主要分布在100~180 cm土层,累积峰在小麦季基础上又向下移动了20 cm。玉米能利用前茬残留于土壤深层的15N,P0、P60、P120处理15N的利用率分别为1.2%、2.5%、2.2%。前茬施磷对后作玉米下层根系发育仍有促进作用,增加了80~150 cm土层根长密度和根干重比例,提高了施磷处理对残留15N的利用率。【结论】前茬耕层施磷仍影响土壤深层累积NO3--N后效,促进后作玉米中下层根系发育,提高深层氮素利用率,进而减少其在土壤剖面中的残留。

关键词: 15N运移, 夏玉米, 硝态氮, 后效, 根系

Abstract:

【Objective】 The purpose of this study was to indicate the effects of phosphate fertilizer applied to topsoil on the movement and residual effect of nitrate which was accumulated in deep soil profile in North China Plain. 【Method】 The injection technique of labeled NO3--N was adopted in a field micro-plot experiment. Three phosphate fertilizer treatments were desigred at each experimental site. The labeled NO3--N was injected in 110 cm soil profile. 【Result】 At this condition, the distribution of residual amount of 15N in each soil profile after wheat harvest was: P60<P120<P0. The labeled NO3--N moved at vertical distance. It moved 50 cm to the topper soil profile and 70 cm to the lower.The peak appeared in the depth of 120-140 cm where it was 30 cm below the labeled place. After maize harvest , most 15N was detected in 100-180 cm. The peak moved to 140-160 cm. Maize could absorb the residual 15N with the utilization ratio of nitrate 1.2%, 2.5%, and 2.2% for the treatments of P0, P60, and P120, respectively. The phosphate fertilizer which was applied to topsoil in wheat season made the roots of maize grow better with more root length density and dry root weight than without phosphate fertilizer. The phosphate fertilizer improved the proportion of root length density and dry root weight in 80-150 cm. More deep soil nitrate could be used by maize, so the utilization ratio of nitrate improved.【Conclusion】The residual effect of 15N was influenced by phosphate fertilizer which was applied to wheat. Phosphate fertilizer made the maize roots grow better in 80-150 cm soil profile. So the utilization ratio of nitrate was improved. The accumulation of 15N in soil profile was reduced.

Key words: 15N movement, maize, nitrate, residual effect, roots