原状土,间歇淋洗长期通气培养,起始矿质氮,土壤可矿化氮,植物吸氮量," /> 原状土,间歇淋洗长期通气培养,起始矿质氮,土壤可矿化氮,植物吸氮量,"/> undisturbed soil,long-term alternate leaching aerobic incubation,soil initial nitrogen,soil mineralization nitrogen,crop nitrogen uptake
,"/> <font face="Verdana">原状土通气培养法测定黄土高原土壤供氮能力的研究</font>

中国农业科学 ›› 2009, Vol. 42 ›› Issue (7): 2397-2406 .doi: 10.3864/j.issn.0578-1752.2009.07.019

• 土壤肥料·节水灌溉·农业生态环境 • 上一篇    下一篇

原状土通气培养法测定黄土高原土壤供氮能力的研究

赵 坤,李世清,李生秀   

  1. (西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室)
  • 收稿日期:2008-10-07 修回日期:2008-11-28 出版日期:2009-07-10 发布日期:2009-07-10
  • 通讯作者: 李世清

Study on Undisturbed Soil Sample Incubation for Estimating Soil Nitrogen Supplying Capacity in Loess Plateau#br#

ZHAO Kun, LI Shi-qing, LI Sheng-xiu#br#   

  1. (西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室)
  • Received:2008-10-07 Revised:2008-11-28 Online:2009-07-10 Published:2009-07-10
  • Contact: LI Shi-qing

摘要:

【目的】评价原状土通气培养法在反映黄土高原土壤供氮能力方面的效果。【方法】以采自于黄土高原差异较大的11个农田耕层土壤为供试土样,以包括和不包括土壤起始NO3--N原状土盆栽黑麦草累积吸氮量为参比,进行室内原状土通气培养法测定土壤供氮能力的研究。【结果】以包括土壤起始NO3--N盆栽试验植物吸氮量为参比,通气培养前CaCl2所淋洗起始NO3--N和起始矿质氮与5期黑麦草地上部氮素累积量密切相关,相关系数分别为0.856和0.862,达1%显著水平;与此相反,通气培养30周所矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、氮素矿化势(N0)及N0+起始矿质氮与5期黑麦草地上部氮素累积量间无显著相关关系,相关系数分别仅为0.410、0.553、0.492和0.419。以不包括土壤起始NO3--N盆栽试验植物吸氮量为参比,通气培养前CaCl2淋洗起始NO3--N和起始矿质氮与五期黑麦草地上部氮素累积量间的相关性尽管有所降低,但相关性仍达5%显著水平,相关系数分别为0.613和0.607;而通气培养30周矿化氮素、土壤起始矿质氮+通气培养30周矿化氮素、N0及N0+起始矿质氮与五期黑麦草地上部吸氮量的相关系数却明显提高,相关系数分别为0.718,0.782,0.688和0.640,均达5%或1%显著水平。【结论】土壤起始NO3--N可作为石灰性土壤当前供氮指标,但该指标难以反映土壤潜在供氮能力;要判断原状土实验室通气培养法是否能可靠评价土壤潜在供氮能力,应以不包括土壤起始NO3--N盆栽试验植物吸氮量作为参比,否则由于受盆栽试验土壤起始NO3--N干扰,用植物吸氮量难以对原状土通气培养法的可靠性作出判断。

关键词: 原状土')">原状土, 间歇淋洗长期通气培养, 起始矿质氮, 土壤可矿化氮, 植物吸氮量

Abstract:

【Objective】The purpose is to assess the effects of N supplying capacity on Loess Plateau using long-term alternate leaching aerobic incubation with undisturbed soils. 【Method】 Based on the results from pot experiments treated with leaching soil initial NO3--N and non-leaching soil initial NO3--N, long-term alternate leaching aerobic incubation with undisturbed soil samples was conducted to study the soil nitrogen supplying capacity of 11 surface soil with different fertilities on Loess Plateau. 【Result】 The results indicated that when initial NO3--N was not leached, soil initial NO3--N and mineral N extracted by CaCl2 before aerobic incubation were closely related with raygrass nitrogen uptake, the correlation coefficients were 0.856 and 0.862, respectively, both reached at 1% significant level. When initial NO3--N was leached,, it was no good relationship between mineralizable N extracted by aerobic incubation, soil initial mineral N and mineralizable N extracted by aerobic incubation, N0 and soil initial mineral N and N0 with raygrass nitrogrn uptake, the correlation coefficients were 0.410, 0.553, 0.492 and 0.419, respectively, indicating that the poor effects of mineralizable N on reflecting soil N capacity were influenced and disturbed by initial nitrate. When initial NO3--N was leached, the correlation coefficients between soil initial NO3--N and mineral N extracted by CaCl2 before aerobic incubation with raygrass nitrogen uptake were decreased to 0.613 and 0.607, respectively, and both reached 5% significantly level. However, the correlation coefficients between mineralizable N extracted by aerobic incubation, soil initial mineral N and mineralizable N extracted by aerobic incubation, N0 and soil initial mineral N and N0 with raygrass nitrogen uptake were raised obviously, and all reached 5% and 1% significant level. 【Conclusion】 It is concluded that NO3--N in soil extracted by CaCl2 before aerobic incubation is a good soil N index, reflecting soil N supplying capacity at present, but it is difficult to reflect soil potential N supplying capacity, and the long-term alternate leaching aerobic incubation with undisturbed soils is good laboratory method to estimate soil nitrogen supplying capacity, if compared with plant nitrogen uptake in pot experiment with leaching soil initial NO3--N.

Key words: undisturbed soil')">undisturbed soil, long-term alternate leaching aerobic incubation, soil initial nitrogen, soil mineralization nitrogen, crop nitrogen uptake