Journal of Integrative Agriculture ›› 2021, Vol. 20 ›› Issue (8): 2265-2276.DOI: 10.1016/S2095-3119(20)63435-9

所属专题: 农业生态环境-土壤微生物合辑Agro-ecosystem & Environment—Soil microbe

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  • 收稿日期:2020-03-30 出版日期:2021-08-01 发布日期:2021-07-20

Effects of long-term straw incorporation on nematode community composition and metabolic footprint in a rice–wheat cropping system

CHEN Yun-feng, XIA Xian-ge, HU Cheng, LIU Dong-hai, QIAO Yan, LI Shuang-lai, FAN Xian-peng   

  1. Key Laboratory of Fertilization from Agricultural Wastes, Ministry of Agriculture and Rural Affairs/Institute of Plant Protection and Soil Fertilizer, Hubei Academy of Agricultural Sciences, Wuhan 430064, P.R.China
  • Received:2020-03-30 Online:2021-08-01 Published:2021-07-20
  • Contact: Correspondence XIA Xian-ge, Tel: +86-27-87389819, E-mail: 13607123150@139.com
  • About author:CHEN Yun-feng, Tel: +86-27-88430575, E-mail: chen971314@ 163.com;
  • Supported by:
    This study was funded by the Open Project of Key Laboratory of the Ministry of Agriculture and Rural Affairs, China (KLFAW201705), the National Natural Science Foundation of China (31870501), the Technological Achievements Cultivation Project of Hubei Academy of Agricultural Sciences (2017CGPY01) and the Key Project of Technological Innovation in Hubei Province, China (2018ABA091).

摘要:

土壤线虫群落能指示土壤食物网结构与功能,对短期秸秆还田等农业管理措施比较敏感。但目前关于不同肥力条件下长期秸秆还田对线虫群落的影响研究较少。基于13年长期秸秆还田试验,本研究通过分析线虫群落结构、食物网指数、代谢足迹,评价了低肥力(不施肥化肥)和高肥力条件下(长期施用化肥)秸秆还田对土壤食物网结构和功能的影响。试验设置4个处理,分别为低肥力条件下秸秆不还田处理和还田处理,高肥力条件下秸秆不还田处理和还田处理。2018年在小麦和水稻收获后取样,取样深度20 cm。结果表明:低肥力条件下,与不还田处理相比,秸秆还田处理线虫总丰度、食细菌线虫丰度、植物寄生线虫丰度、杂食-捕食线虫丰度及占线虫总丰度的比例分别比不还田处理高73.06%,89.29%,95.31%,238.98%和114.61%,高肥力条件下则分别高16.23%,2.23%,19.01%,141.38%和90.23%。在不考虑取样时间和肥力条件下,与不还田处理相比,秸秆还田提高了线虫群落仙农-维纳指数和成熟度指数,表明秸秆还田提高了线虫群落多样性和稳定性。此外,秸秆还田对线虫群落富集指数、富集足迹、食细菌线虫和食真菌线虫代谢足迹影响不显著,但显著提高了植物寄生线虫代谢足迹和结构足迹,低肥力条件下提高了97.27%和305.39% ,高肥力条件下提高了11.29%和149.56%,对结构指数的影响尽管在统计上不显著,但呈现出上升的趋势,这表明秸秆还田对线虫群落的自下而上调节能力较弱,而自上而下调节能力较强。总之,长期秸秆还田主要通过自上而下效应调节线虫群落,提高了线虫群落丰度,改变了线虫群落结构,且在低肥力条件下作用更强。


Abstract:

Soil nematode communities can provide valuable information about the structure and functions of soil food webs, and are sensitive to agricultural practices, including short-term straw incorporation.  However, currently, such effects under long-term straw incorporation conditions at different fertility levels are largely unknown.  Thus, we conducted a 13-year ongoing experiment to evaluate the effects of long-term straw incorporation on the structure and functions of the soil food web in low and high fertility soils through analyzing its effects on nematode communities, food web indices and metabolic footprints.  Four treatments were included: straw removal (–S) under non-fertilized (–NPK) or fertilized (+NPK) conditions; and straw incorporation (+S) under –NPK or +NPK conditions.  Soil samples from a 0–20 cm depth layer were collected when wheat and rice were harvested.  Compared with straw removal, straw incorporation increased the abundances of total nematodes, bacterivores, plant-parasites and omnivores-predators, as well the relative abundances of omnivores-predators with increases of 73.06, 89.29, 95.31, 238.98, and 114.61% in –NPK soils and 16.23, 2.23, 19.01, 141.38, and 90.23% in +NPK soils, respectively.  Regardless of sampling times and fertilization effects, straw incorporation increased the diversity and community stability of nematodes, as indicated by the Shannon-Weaver diversity index and maturity index.  Enrichment and structure index did not show significant responses to straw incorporation, but a slight increase was observed in the structure index.  The analysis of nematode metabolic footprints showed that straw incorporation increased the plant-parasite footprint and structure footprint by 97.27 and 305.39% in –NPK soils and by 11.29 and 149.56% in +NPK soils, but did not significantly influence enrichment, bacterivore and fungivore footprints.  In conclusion, long-term straw incorporation, particularly under a low fertility level, favored the soil nematodes and regulated the soil food web mainly via a top-down effect.   

Key words: soil nematodes ,  community composition ,  metabolic footprint ,  straw incorporation ,  rice–wheat cropping system ,  top-down effect