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Title:Long-term n fertilization affects soil bacterial communities in agronomic fields
Author(s):Sun, Renpeng
Advisor(s):Villamil, Maria Bonita
Department / Program:Crop Sciences
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):long-term N fertilization
soil bacterial communities
Abstract:Soil microbial communities influence plant productivity, chemistry and structure of soil and nutrient cycling. In turn, long-term nitrogen fertilization changes soil physical and chemical properties and thus influences soil microbiomes. In-depth understanding of the long-term nitrogen fertilization effects on soil microbial communities is critical for improving fertilization practices to optimize the microbiomes for soil health, productivity and sustainability. Our goal was to characterize the microbial community structure under long-term N gradient treatment in continuous corn (CCC) and to investigate the response of different soil microbial groups involved in the N cycle to different N fertilization levels. Field trial in CCC on three N fertilization rates (0, 210, and 280 kg N/ha) is arranged in a randomized complete block design (RCBD) with three replications. Using 16S rRNA gene-based pyrosequencing analysis of the V4 region and DNA extracted from soil in a 33-year-old agricultural field trial, we characterized the structure, composition and nitrogen cycling function of the bacterial communities involved. The downstream bioinformatics processing and analysis were conducted with QIIME (Quantitative Insights Into Microbial Ecology). V4 region of 16S rDNA gene sequences were clustered into operational taxonomic units (OTUs) and the bacterial community composition and diversity were analyzed based on the OTUs extracted. We applied principal component analyses (PCA) and canonical discriminant analysis (CDA) to our major bacterial phyla dataset. Our results indicate that high N fertilization level tended to decrease the diversity and richness of soil bacterial community and altered the relative abundance of the major bacterial phyla. There was a significant response of different soil bacterial groups involved in the N cycle to different N fertilization levels.
Issue Date:2018-04-23
Rights Information:Copyright 2018 Renpeng Sun
Date Available in IDEALS:2018-09-04
Date Deposited:2018-05

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