Journal of Integrative Agriculture

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JIA-2021-1398 适当有机替代缓解了化肥对土壤微食物网的负面影响

  

  • 收稿日期:2021-08-12 修回日期:2021-11-29

Partial organic substitution weakens the negative effect of chemical fertilizer on soil micro-food webs

  1. 1 Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P.R.China
    2 University of Chinese Academy of Sciences, Beijing 100049, P.R.China
    3 School of Geographical Science, Northeast Normal University, Changchun 130024, P.R.China
  • Received:2021-08-12 Revised:2021-11-29
  • About author:LIU Han-wen, Tel:15524252563, E-mail: liuhanwen15@mails.ucas.ac.cn; Correspondence ZHANG Xiao-ke, Tel: +86-24-83970359, E-mail: zxk@iae.ac.cn; LIANG Wen-ju, Tel: +86-24-83970359, E-mail: liangwj@iae.ac.cn
  • Supported by:
    This experiment was conducted at the National Field Observation and Research Station of Shenyang Agro-ecosystems, Liaoning Province. This research was supported by the National Natural Science Foundation of China (41977054, 41771280 and 31330011), and the National Science and Technology Fundamental Resources Investigation Program of China (2018FY100304).

摘要: 土壤生物群落在促进土壤养分循环和肥力方面发挥着重要的作用。长期过量施用氮肥不利于土壤生物群落的稳定,进而影响到农田土壤健康和可持续利用。有机物料替代部分化肥对改善土壤健康和减轻过度化肥施用造成的不利影响至关重要。然而,不同有机物料对土壤微食物网影响的生物学机制尚不清楚。为了探究秸秆、生物炭和粪肥对土壤微食物网(微生物和线虫群落)的影响,本研究设置了田间小区试验,包括100%常规尿素(100% N)、70%常规尿素(70% N)、70%常规尿素加秸秆(Stover)、70%常规尿素加牛粪(Manure)和70%常规尿素加生物炭(Biochar)五个处理。研究结果表明,秸秆提供了更多可利用资源;粪肥提高了土壤微生物碳氮利用效率比值,有助于土壤固碳;生物炭施用显著提高了土壤有机碳含量和pH。此外,生物炭缓解了土壤酸化对土壤微食物网的负面影响,降低了植物寄生虫多度。主坐标分析表明,有机肥与化肥处理(100% N和70% N)对土壤生物,特别是微生物群落组成的影响存在显著差异,体现出不同的生物学机制。与100% N相比,氮肥减施处理土壤特性、微生物生物量和线虫生物量之间的负连接数有所降低。有机物料输入后土壤食细菌线虫通过上行效应影响了上一营养级的捕食-杂食线虫。综上所述,有机替代通过调节农田生态系统土壤微生物和线虫群落组成提高了土壤肥力,缓解了化肥对微食物网的负面影响,调控了土壤生物之间的营养级联效应。

Abstract: Soil biotic communities play vital roles in enhancing soil nutrient cycling and soil fertility. Long-term excessive nitrogen (N) application is disadvantageous to the stability of soil food webs and affects arable soil health and sustainable utilization. Proper organic substitution is essential to improve soil health and alleviate the disadvantages of excessive chemical fertilization. However, the biological effects of various organic amendments on soil micro-food webs are poorly understood. In order to explore the effects of various organic amendments including stover, biochar and manure on soil micro-food webs (microbial and nematode communities), a field plot experiment with maize having five treatments viz., 100% urea (100% N), 70% urea (70% N), 70% urea plus stover (Stover), 70% urea plus cattle manure (Manure) and 70% urea plus biochar (Biochar) was conducted. Manure increased the carbon (C) to N use efficiency of soil microbes, which contributed to the retention of soil C, while biochar elevated soil organic C (SOC) and soil pH. Additionally, biochar mitigated the negative effects of soil acidification on the soil micro-food web and reduced the abundance of plant-parasites. Overall, the biological effect of organic amendments was distinguished from chemical fertilization (100% N and 70% N) through principal co-ordinates analysis. Negative relationships among soil properties, microbial and nematode biomass in the 100% N treatment were diminished in treatments where chemical fertilizer was reduced. The bottom-up effects on soil food webs were observed in organic substitution treatments. In conclusion, organic amendments improved soil fertility by regulating soil microbial and nematode communities in the cropland ecosystem, alleviated the negative effects of chemical fertilizer on the micro-food webs and controlled the trophic cascades among soil biota.

Key words: microbial community ,  nematode community ,  soil micro-food webs ,  organic substitution ,  chemical fertilizer ,  soil health