摘要
【目的】探讨水肥一体化模式下施氮量对玉米根际土壤固氮菌群落及生长的调控效应。【方法】设置5种追肥施氮量,分别为不施氮(N0:0 kg·hm^(-2))、低氮(N1:98 kg·hm^(-2),70%N)、中氮(N2:140 kg·hm^(-2),100%N)、高氮(N3:182 kg·hm^(-2),130%N)和过量氮(N4:210 kg·hm^(-2),150%N),利用高通量测序技术比较不同施氮量下玉米根际土壤固氮菌群落多样性及结构组成差异性,并结合土壤氮素及玉米生长指标,阐释施氮量的调控机制。【结果】施氮显著提高了各生育时期根际土壤氮素含量,并促进了玉米生物量和氮素的积累,N2表现最佳。固氮菌整体α多样性随施氮量增加呈先下降后上升再下降趋势,N2提高了α多样性,而N1和N4降低了多样性。施氮显著影响了固氮菌群落结构,尤其在拔节期和开花期,样本明显分离。菌群组成显示,施氮显著提高了土壤有益微生物慢生根瘤菌属(Bradyrhizobium)的丰度,同时N2提高了促生菌未分类伯克氏菌目(unclassified_o__Burkholderiales)的相对丰度。关联网络分析表明,N2的模块化指数等拓扑参数上调,表明菌群结构更稳定。偏最小二乘路径模型进一步揭示,施氮量通过土壤氮组分间接正向调控玉米生长。【结论】追肥施氮量140 kg·hm^(-2)(N2)时优化了根际土壤生态环境,增强固氮菌群落稳定性并促进玉米生长,建议作为半干旱区玉米水肥一体化种植参考施氮量。
【Objective】Effects of nitrogen(N)application rate on N-fixing microbial communities in rhizosphere soil and maize growth on land under integrated irrigation-fertilization model were analyzed.【Method】N-topdressing with no N(N0 as control),70%N at 98 kg·hm^(-2)(N1),100%N at 140 kg·hm^(-2)(N2),130%N at 182 kg·hm^(-2)(N3)or 150%N at 210 kg·hm^(-2)(N4)was applied on a maize growing field.High-throughput sequencing was conducted to compare the differences in the diversity and composition of N-fixing microbial communities in the rhizosphere soil.Growth of maize plants on the lots were correlated to the collected data on the soil at the same lot.【Result】Application of N fertilizer significantly increased the soil N as well as the maize biomass and N accumulation at growth stages.N2 yielded the optimal performance among all treatments.Theα-diversity of N-fixing microbes in the rhizosphere soil decreased at first as the N application rate increased.It was followed by an increase and another decline.Of all treatments,N2 enhanced theα-diversity but N1 and N4 suppressed it.N-application significantly affected the soil microbial community structure,particularly during the jointing and flowering stages of maize.It also significantly raised the abundance of beneficial species,such as Bradyrhizobium.Notably,N2 enriched the relative abundance of plant growth-promoting bacteria of the unclassified order Burkholderiales.The upregulated modularity index and other topological parameters of the network analysis suggested a more stable community structure under N2 as well.The partial least squares path modeling further indicated that the rate of N-application indirectly stimulated the maize growth by way of altering the N composition in soil.【Conclusion】The N-application at a rate of 140 kg·hm^(-2)(N2)appeared to optimize the soil N,stabilize the N-fixing microbial community,and promote the maize growth.Consequently,it was recommended for maize farming under the integrated irrigation-fertilization practice.
作者
徐莹莹
王宇先
高盼
杨慧莹
张巩亮
申惠波
刘玉涛
XU Yingying;WANG Yuxian;GAO Pan;YANG Huiying;ZHANG Gongliang;SHEN Huibo;LIU Yutao(Qiqihar Branch of Heilongjiang Academy of Agricultural Sciences,Qiqihar,Heilongjiang 161006,China;Zhang Xingyi Soil Science Scientist Studio of Chinese Academy of Sciences,Qiqihar,Heilongjiang 161006,China)
出处
《福建农业学报》
北大核心
2025年第6期637-648,共12页
Fujian Journal of Agricultural Sciences
基金
黑龙江省农业科技创新跨越工程基础创新优青项目(CX23YQ20)
中国科学院张兴义土壤学科学家工作室补助项目(202001)
齐齐哈尔市科技计划创新激励项目(CNYGG2023023)。
关键词
玉米
水肥一体化
施氮量
根际土壤
固氮菌群落
maize
integrated irrigation-fertilization
nitrogen application rate
rhizosphere soil
nitrogen-fixing microbial community
