摘要
马铃薯是保障粮食安全的重要作物,但长期连作会导致土壤退化与土传病害加剧,威胁其可持续发展。土壤线虫是土壤健康与食物网动态的关键指标。本研究依托甘肃定西15年马铃薯定位试验,设置1、5、10、15年连作处理(编号分别为T1、T5、T10、T15),通过高通量测序与土壤理化性质分析,探讨线虫群落结构演替及驱动机制。结果表明,长期连作显著降低土壤pH(从T1的8.28降至T15的8.14,P<0.05)和有机质含量(T5至T15降幅显著),而速效氮、磷、钾累积(T15达峰值,P<0.05)导致C∶N∶P化学计量失衡。β多样性分析(PCoA)显示,5~10年为群落结构转折期,解释57.06%的变异。食细菌线虫相对丰度由15%增至24%,Monhysterida由9%增至15%(P<0.05),标志着食物网从“真菌通道”向“细菌通道”转变;植物寄生线虫呈“先增后降”趋势(T5峰值,T10和T15显著下降,P<0.05)。马铃薯经济产量在15年连作后下降39.55%,同时腐烂薯率按重量计激增至T1的15.8倍,商品薯率大幅下降。经RDA和Mantel检验确认,土壤有机质和pH是群落演替的关键驱动因子。本研究提出了“连作两阶段演替模型”,并指出通过施用高碳有机物料以重建真菌主导的能量通道,是破解连作障碍、实现退化农田生态修复的关键策略。
Potato is a vital crop for global food security.However,long-term continuous cropping leads to soil degradation and intensifies soil-borne diseases,posing a significant threat to sustainable production.Soil nematodes are important bioindicators of soil health and food web dynamics.In this study,we investigated nematode community succession and its underlying drivers in a 15-year potato monoculture experiment in Dingxi,Gansu,China.Four continuous cropping durations—1,5,10,and 15 years(T1,T5,T10,T15)—were evaluated using high-throughput sequencing and soil physicochemical analysis.Results showed that prolonged continuous cropping significantly reduced soil pH from 8.28(T1)to 8.14(T15)(P<0.05)and decreased soil organic matter content,particularly between T5 and T15.In contrast,available nitrogen,phosphorus,and potassium increased and peaked at T15(P<0.05),resulting in a disrupted C:N:P stoichiometric balance.Beta-diversity analysis(PCoA)indicated that years 5-10 represent a critical transition period in nematode community structure,explaining 57.06% of the variation.The relative abundance of bacterivorous nematodes increased from 15%(T1)to 24%(T15),with Monhysterida rising from 9% to 15%(P<0.05),suggesting a shift in the soil food web from a fungal-to a bacterial-dominated energy pathway.Plant-parasitic nematodes followed a nonlinear“rise-then-fall”pattern,peaking at T5 and declining significantly at T10 and T15(P<0.05).After fifteen years of continuous cropping,potato economic yield declined by 39.55%,the rot rate by weight increased 15.8-fold,and the proportion of marketable potatoes declined sharply.Redundancy analysis(RDA)and Mantel tests identified soil organic matter and pH as key drivers of nematode community succession.Based on these findings,we propose a two-stage succession model for nematode communities under continuous cropping.We further suggest that applying high-carbon organic amendments to restore fungal-dominated energy channels is a promising strategy to alleviate continuous cropping obstacles and support the ecological restoration of degraded farmland.
作者
徐强
谢奎忠
胡新元
岳云
董博
罗爱花
Xu Qiang;Xie Kui-Zhong;Hu Xin-Yuan;Yue Yun;Dong Bo;Luo Ai-Hua(College of Resources and Environment,Gansu Agricultural University,Lanzhou 730070,Gansu,China;Potato Research Institute,Gansu Academy of Agricultural Sciences,Lanzhou 730070,Gansu,China;Gansu Academy of Agricultural Engineering Technology,Lanzhou 730030,Gansu,China;Institute of Dryland Agriculture,Gansu Academy of Agricultural Sciences,Lanzhou 730070,Gansu,China)
出处
《作物学报》
北大核心
2026年第2期527-538,共12页
Acta Agronomica Sinica
基金
甘肃省科技计划项目(25CXNA016)
国家自然科学基金项目(31860354)
甘肃省青年科技攻关“揭榜挂帅”项目(GQK2024034)
甘肃省农业科学院重点研发计划项目(2022GAAS36)
甘肃省农业科学院立项项目(2024MLS06)资助。
关键词
马铃薯
连作
土壤线虫群落结构
群落演替
食物网
potato
continuous cropping
soil nematode community structure
community succession
food web
