中国农业科学 ›› 2016, Vol. 49 ›› Issue (13): 2561-2571.doi: 10.3864/j.issn.0578-1752.2016.13.012

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

施氮量对不同肥力土壤氮素转化及其利用率的影响

杨馨逸,刘小虎,韩晓日   

  1. 沈阳农业大学土地与环境学院,沈阳 110866
  • 收稿日期:2016-03-01 出版日期:2016-07-01 发布日期:2016-07-01
  • 通讯作者: 刘小虎,E-mail:liuxiaohu-mail@163.com。韩晓日,E-mail:hxr@syau.edu.cn
  • 作者简介:杨馨逸,E-mail:15802414046@163.com
  • 基金资助:
    国家自然科学基金(31471940)、国家现代农业产业技术体系水稻产业辽宁创新团队建设(辽农科[2013]271号)

Effect of Nitrogen Application Rates in Different Fertility Soils on Soil N Transformations and N Use Efficiency Under Different Fertilization Managements

YANG Xin-yi, LIU Xiao-hu, HAN Xiao-ri   

  1. College of Land and Environmental Science, Shenyang Agricultural University, Shenyang 110866
  • Received:2016-03-01 Online:2016-07-01 Published:2016-07-01

摘要: 【目的】评价不同施氮量下不同肥力土壤在小麦孕穗期的土壤活性氮组分(土壤矿质氮、可溶性有机氮和微生物量氮)的转化与氮肥利用率的变化。【方法】以长期(37年)定位试验下不同施肥处理土壤(贫瘠土壤-NF:长期不施肥;低肥力土壤-LF:长期施用化肥;中肥力土壤-MF:长期施用低量有机肥配施无机肥;高肥力土壤-HF:长期施用高量有机肥配施无机肥)为研究对象,通过盆栽试验,利用15N示踪法,研究添加外源硫酸铵氮肥(N0:0、N1:135 kg·hm-2、N2:180 kg·hm-2)之后,小麦生长旺盛时期(孕穗期)土壤活性氮组分在不同肥力土壤中的变化以及与土壤供氮效应之间的联系。【结果】随施氮量增加,不同肥力土壤的可溶性氮均呈先增加后降低的趋势,在N1处理最高,而各处理的土壤微生物量氮在N2达到最大,N1最低;不同肥力土壤可溶性氮变化均为高肥力土壤>中肥力土壤>低肥力土壤>贫瘠土壤,而微生物量氮变化均为高肥力土壤>中肥力土壤>贫瘠土壤>低肥力土壤(P<0.05);施氮对不同肥力土壤可溶性氮和微生物量氮的影响在低肥力土壤最大,而在高肥力土壤增幅最小。不同肥力土壤供氮量、氮肥利用率以及吸氮总量和吸15N量的变化均为高肥力土壤>中肥力土壤>低肥力土壤>贫瘠土壤(P<0.05),其中,吸收15N量所占小麦吸收总氮的百分比大小变化为低肥力土壤>中肥力土壤>高肥力土壤>贫瘠土壤(P<0.05)。相同肥力不同处理下,土壤供氮量、氮肥利用率以及小麦吸氮量和吸15N肥料的量随施氮量的增加呈先增加后降低的趋势,均以N1处理显著高于其他处理(P<0.05),总体上施氮处理下小麦吸肥料氮所占吸收总氮的百分比的平均值为44%;各肥力土壤中肥料损失量均为贫瘠土壤>低肥力土壤>中肥力土壤>高肥力土壤(P<0.05),而且氮肥损失量均随施氮量的增加而增加,在N2处理最大;土壤活性氮组分与土壤供氮、氮肥利用率、小麦吸氮之间均具有显著的正相关关系(P<0.05)。【结论】在高肥力土壤上添加适宜氮量(135 kg·hm-2)利于土壤中活性氮组分的转化,能更好地协调土壤供氮与作物需氮间的关系,提高氮肥利用率,减少氮素在土壤中的损失。

关键词: 施氮量, 不同肥力土壤, 土壤矿质氮, 土壤可溶性有机氮, 土壤微生物量氮, 氮肥利用率

Abstract: 【Objective】 The objective of this study is to research the effect of different nitrogen (N) application rates on soil labile N pools transformations (soil mineral N-SMN; soil soluble N-SSON; soil microbial biomass N-SMBN) and N use efficiency in soils after application of N fertilizer at wheat (Triticum aestivum L.) booting stage. 【Method】 A pot experiment with 15N isotopic tracer technique was conducted to study the soil labile N pools and the effect of supply N in different fertilization managements for 37 years (poor soil-NF: no application of fertilizer; low fertility soil-LF: inorganic fertilizer; moderate fertility soil-MF: low rate of organic fertilizer with inorganic fertilizer; high fertility soil-HF: high rate of organic fertilizer with inorganic fertilizer) after application of three different application rates of N (N0: 0, N1: 135 kg·hm-2, N2: 180 kg·hm-2) in soil and their relationships. 【Result】 SMN and SSON were the highest in the N1 treatment and then decreased with the application rate of N, but SMBN performed opposite tendency with the application rate of N, they were firstly decreased and then increased, and the highest in the N2 treatment. In the same application rate of N, SMN and SSON generally decreased in the order: high fertility soil>moderate fertility soil>low fertility soil>poor soil, while SMBN generally decreased in the order: high fertility soil>moderate fertility soil>poor soil>low fertility soil (P<0.05). The increased amplitude of SMN, SSON and SMBN after addition of N into soils with different fertilities were the highest in the low fertility soil treatments, and were the lowest in the high fertility soil treatments. The soil N supply, NUE, N uptake by wheat and assimilated 15N-labeled fertilizer generally decreased in the order: high fertility soil>moderate fertility soil>low fertility soil>poor soil (P<0.05), respectively. The percentage of N from ammonium sulfate fertilizer by wheat to total N uptake by wheat generally decreased in the order: low fertility soil>moderate fertility soil>high fertility soil>poor soil (P<0.05). In the same soil fertility, the soil N supply, NUE, N uptake by wheat and assimilated 15N-labeled fertilizer were firstly decreased and then increased with the application rate of N, and were the highest in the N1 treatment (P<0.05), as a whole, N from ammonium sulfate fertilizer by wheat/total N uptake ratio averaged 44%; meanwhile, the loss of 15N-labeled fertilizer generally decreased in the order: poor soil>low fertility soil>moderate fertility soil>high fertility soil (P<0.05). Furthermore, significant positive relationships were found between soil labile N pools and the soil N supply, NUE, N uptake by wheat and assimilated 15N-labeled fertilizer (P<0.05). 【Conclusion】 In this experiment, appropriate application rate of N fertilizer (N3, 135 kg·hm-2) in high fertility soil is beneficial to soil labile N pools transformations and has a high ability to synchronize the relationship between soil N supply and N requirements of crops, and increased the NUE, decreased the loss of fertilizer, so it may be an effective strategy for maintaining long-term soil fertility.

Key words: application rate of N, different fertility soils, soil mineral N, soil soluble organic N, soil microbial biomass N, N use efficiency