摘要
为了探究大豆短期连作对土壤理化性质及微生物群落结构的影响,以新植(CK)、连作2 a(T1)、连作3 a(T2)的大豆根际土壤为研究对象,采用高通量测序技术结合土壤理化性质分析,揭示大豆短期连作障碍的关键驱动因素。结果表明:土壤养分整体呈现先升后降的特征,有效磷(AP)含量在T1时升高,在T2处降低至6.73 mg/kg,仅有CK的42.06%;速效钾(AK)和有机质(OM)含量连作3 a后分别比CK降低38.68%和10.59%;土壤pH值下降至6.15。微生物群落的多样性及丰富度在大豆连作2 a后均有增加,但连作3 a后又降至CK阶段水平,真菌子囊菌门的相对丰度降至39.43%,较CK减少了21.54个百分点,而被孢霉门相对丰度增加了12.24个百分点,细菌酸杆菌门相对丰度保持不变,变形菌门相对丰度较CK上升3.83个百分点。相关性分析结果显示,子囊菌门与AK及pH值显著正相关;而被孢霉门与TP正相关,但与OM、AK及pH值负相关;酸杆菌门与TK及pH值显著正相关,与HN、AP呈显著负相关;变形菌门与TP、TK及HN显著正相关,但与TN、OM及pH值显著负相关,绿弯菌门与OM、AK显著正相关。因此,笔者认为,当土壤有效磷含量低于10 mg/kg、子囊菌门丰度低于40%时,常伴随土壤质量下降和微生物群落失调,可作为短期连作风险的初步预警指标。
This study aims to investigate the impact of short-term continuous soybean cropping on soil physicochemical properties and microbial community structure.Rhizosphere soil samples were collected from the fields with new soybean cropping(CK),continuous soybean cropping for 2 years(T1),and continuous soybean cropping for 3 years(T2).High-throughput sequencing was combined with physicochemical property analysis to elucidate the key driving factors behind the obstacles associated with shortterm continuous soybean cropping.The results showed that soil nutrients exhibited a characteristic pattern of first increasing and then decreasing.The content of available phosphorus(AP)elevated in T1 and declined to 6.73 mg/kg(only 42.06%of that in CK)in T2.The content of available potassium(AK)and organic matter(OM)in T2 decreased by 38.68%and 10.59%,respectively,compared with that in CK.The soil pH value dropped to 6.15.The microbial diversity and richness increased in T1.However,in T2,both indices decreased to the levels comparable to those in CK.The relative abundance of Ascomycota reached 39.43%,decreasing by 21.54 percentage points compared with that in CK,while the relative abundance of Mortierellomycota increased by 12.24 percentage points.The relative abundance of Acidobacteriota remained stable,while the relative abundance of Proteobacteria increased by 3.83 percentage points compared with that in CK.The correlation analysis showed that the relative abundance of Ascomycota had significantly positive correlations with AK and pH,while that of Mortierellomycota was positively correlated with total phosphorus(TP)but negatively correlated with OM,AK,and pH.The relative abundance of Acidobacteria had significantly positive correlations with total potassium(TK)and pH but significantly negative correlations with HN and AP.The relative abundance of Proteobacteria had significantly positive correlations with TP,TK,and HN but significantly negative correlations with TN,OM,and pH.The relative abundance of Chloroflexi had significantly positive correlations with OM and AK.In conclusion,under short-term continuous soybean cropping,the AP content below 10 mg/kg and the relative abundance of Ascomycota below 40%are often accompanied by soil quality deterioration and microbial community imbalance,and thus they can be taken as the warning indicators of short-term continuous cropping obstacles.
作者
刘依依
张津浩
张清壮
肖维涛
刘琼
周池
LIU Yi-yi;ZHANG Jin-hao;ZHANG Qing-zhuang;XIAO Wei-tao;LIU Qiong;ZHOU Chi(Hanshou Bureau of Agriculture and Rural Affairs,Changde 415900,PRC;Hunan Institute of Microbiology,Changsha 410125,PRC;Hunan Engineering Research Center for Exploration and Utilization of Plant Endophytic Microbial Resources,Changsha 410125,PRC;Anshun University,Anshun 561000,PRC;Yuanjiang Bureau of Agriculture and Rural Affairs,Yiyang 413100,PRC)
出处
《湖南农业科学》
2025年第11期18-24,共7页
Hunan Agricultural Sciences
基金
国家重点研发计划(2022YFD1700100)
湖南省农业科技创新资金项目(2024CX50,2024CX115)。
关键词
大豆
连作障碍
土壤养分
土壤微生物
微生物群落
soybean
continuous cropping obstacles
soil nutrients
soil microorganisms
microbial community
