Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (10): 2758-2771.DOI: 10.1016/S2095-3119(21)63646-8

所属专题: 昆虫合辑Plant Protection—Entomolgy 农业生态环境-有机碳与农业废弃物还田合辑Agro-ecosystem & Environment—SOC

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  • 收稿日期:2020-12-14 出版日期:2021-10-01 发布日期:2021-08-09

Changes in organic C stability within soil aggregates under different fertilization patterns in a greenhouse vegetable field

LUAN Hao-an1, 2*, YUAN Shuo1*, GAO Wei3, TANG Ji-wei1, LI Ruo-nan4, ZHANG Huai-zhi1, HUANG Shao-wen1
  

  1. 1 Institute of Agricultural Resources and Regional Planning/Key Laboratory of Plant Nutrition and Fertilizer of Ministry of Agriculture and Rural Affairs, Chinese Academy of Agricultural Sciences, Beijing 100081, P.R.China
    2 College of Forestry, Hebei Agricultural University, Baoding 071000, P.R.China
    3 Tianjin Institute of Agricultural Resources and Environment, Tianjin 300192, P.R.China
    4 Institute of Agricultural Resources and Environment, Hebei Academy of Agriculture and Forestry Sciences, Shijiazhuang 050051, P.R.China
  • Received:2020-12-14 Online:2021-10-01 Published:2021-08-09
  • Contact: Correspondence TANG Ji-wei, Tel: +86-10-82105027, E-mail: tang-jiwei@163.com; HUANG Shao-wen, Tel: +86-10-82108662, E-mail: huangshaowen@caas.cn
  • About author:LUAN Hao-an, E-mail: luanhaoan@163.com; YUAN Shuo, E-mail: yuanshuoxx@163.com; * These authors contributed equally to this study.
  • Supported by:
    The authors sincerely acknowledge the financial support provided by the China Agriculture Research System of MOF and MARA (CARS-23-B02), the National Key Research and Development Program of China (2016YFD0201001), and the scientific research projects for talents introduce in Hebei Agricultural University (YJ2020054).

摘要:

理解土壤有机碳(SOC)的稳定性对于农业生态系统中SOC循环及其动态变化至关重要。已有研究观察到施肥对土体土壤中有机碳稳定性的调节作用。然而,在农业生态系统中,施肥如何改变土壤团聚体中有机碳的稳定性尚不清楚。本研究旨在评估中国天津设施蔬菜施肥8年(化肥vs有机措施)后土壤团聚体中有机碳稳定性的变化。为评估土壤团聚体中有机碳的稳定性变化,本研究采用如下四种方法:改良的Walkley-Black方法(化学方法),13C NMR技术(光谱法),胞外酶测定(生物方法)和热重分析法(热力学方法)。通过湿筛方法将土壤分离成四部分:宏团聚体(> 2 mm),大团聚体(0.25–2 mm),微团聚体(0.053–0.25 mm)和粉粘粒(<0.053 mm)。结果表明,与单施化肥模式相比,有机措施可增加土壤团聚体中有机碳含量,并降低有机碳化学、光谱学、热力学和生物学稳定性。在土壤各团聚体中,有机碳含量在微团聚体中最高,其次为宏团聚体和大团聚体,粉粘粒中最低。同时,有机碳光谱学、热力学和生物学稳定性在粉粘粒中最高,其次是宏团聚体和大团聚体,微团聚体内有机碳稳定性最低。此外,由于土壤团聚体内有机碳化学性质与其他稳定性特征之间的相关性较弱,故推断改良的Walkley-Black方法不适用于评价土壤团聚体内有机碳的稳定性。我们的发现可在土壤团聚体水平上,为深入探索中国设施菜田不同施肥模式下有机碳特性的变化提供科学见解。


Abstract:

Knowledge of the stability of soil organic C (SOC) is vital for assessing SOC dynamics and cycling in agroecosystems.  Studies have documented the regulatory effect of fertilization on SOC stability in bulk soils. However, how fertilization alters organic C stability at the aggregate scale in agroecosystems remains largely unclear.  This study aimed to appraise the changes of organic C stability within soil aggregates after eight years of fertilization (chemical vs. organic fertilization) in a greenhouse vegetable field in Tianjin, China.  Changes in the stability of organic C in soil aggregates were evaluated by four methods, i.e., the modified Walkley-Black method (chemical method), 13C NMR spectroscopy (spectroscopic method), extracellular enzyme assay (biological method), and thermogravimetric analysis (thermogravimetric method).  The aggregates were isolated and separated by a wet-sieving method into four fractions: large macroaggregates
(>2 mm), small macroaggregates (0.25–2 mm), microaggregates (0.053–0.25 mm), and silt/clay fractions (<0.053 mm).  The results showed that organic amendments increased the organic C content and reduced the chemical, spectroscopic, thermogravimetric, and biological stability of organic C within soil aggregates relative to chemical fertilization alone.  Within soil aggregates, the content of organic C was the highest in microaggregates and decreased in the order microaggregates>macroaggregates>silt/clay fractions.  Meanwhile, organic C spectroscopic, thermogravimetric, and biological stability were the highest in silt/clay fractions, followed by macroaggregates and microaggregates.  Moreover, the modified Walkley-Black method was not suitable for interpreting organic C stability at the aggregate scale due to the weak correlation between organic C chemical properties and other stability characteristics within the soil aggregates.  These findings provide scientific insights at the aggregate scale into the changes of organic C properties under fertilization in greenhouse vegetable fields in China.

Key words:  fertilization ,  organic C stability ,  soil aggregates , thermogravimetric analysis ,  13C NMR spectroscopy