摘要： 通过室内入渗试验,研究了膜孔灌条件下不同氮肥的转化特性。结果表明,施入铵态氮肥后土壤铵态氮含量在膜孔中心垂向表层0～5.5 cm内变化,再分布15 d土壤铵态氮损失了68%,再分布20 d铵态氮基本完全转化;随再分布时间的延长,硝态氮的含量在土壤表层10 cm范围内逐渐增加,在10 cm以下,硝态氮的含量7 d前先增大再减小,7 d后一直增大。施入硝态氮肥后,硝态氮含量7 d内变化很小,7～10 d内明显减少,10 d以后减少缓慢。施入尿素后,土壤中铵态氮在5 d后达到峰值,20 d后下降至土壤的本底值;而土壤硝态氮一直平稳升高,于施肥20 d后达到最大值;土壤铵态氮含量和硝态氮含量均沿着远离膜孔中心的方向逐渐减小。

关键词: 膜孔灌, 氮肥, 转化特性

Abstract: Based on lab experiment,transformation characteristics of nitrogen under film hole single point infil-tration with different nitrogen fertilizer were researched. Results showed that the transformation laws of nitrogen un-der different nitrogen fertilizer were different. The NH4+-N content at the vertical of film hole center changed in the depth of 0-5.5 cm after fertilization with ammonium fertilizer. The NH4+-N content lost 68%after redistribution of 15 d and it was transformed completely after redistribution of 20 d.With the redistribution time increased,the con-tent of NO3--N increased in the 10 cm scope of soil surface layer. Below the 10 cm scope of soil surface layer,the content of NO3--N first increased and then decreased in 7 d and it always increased after 7 d.The content of nitrate fertilizer changed little in 7 d after fertilization with nitrate nitrogen fertilizer,but it decreased obviously in 7-10 d and it decreased slowly after 10 d.The NH4+-N content came to the maximum value in 5 d after fertilization of urea and decreased to the background value in 20 days.While the NO3--N content increased all along and came to the maximum value in 20 days after fertilization.The soil NH4+-N content and NO3--N content under fertilization de-creased with the distance far from the film hole center. The results lay a foundation for study of film hole irrigation fertilizer technique.

Key words: Film hole irrigation, Nitrogen fertilizer, Transformation characteristics

中图分类号: 

• S143.1