Soil microbial diversity in organic and non-organic pasture systems

PeerJ

article

Mohan Acharya¹  Amanda J. Ashworth²  Yichao Yang³  Joan M. Burke⁴  Jung Ae Lee⁵  Roshani Sharma Acharya⁶ 

[1] Department of Animal Science, University of Arkansas at Fayetteville;Poultry Production and Product Safety Research Unit, United States Department of Agriculture, Agricultural Research Service;Department of Crop, Soil, and Environmental Science, University of Arkansas at Fayetteville;United States Department of Agriculture, Agriculture Research Service, Dale Bumpers Small Farms Research Center;Agriculture Statistics Lab, University of Arkansas at Fayetteville;Entomology and Plant Pathology, University of Arkansas at Fayetteville

关键词: Organic and non-organic livestock pasture;    Soil microbiome;    Microbial abundance;    16S rRNA gene amplicons;   

DOI  :  10.7717/peerj.11184

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Understanding the effects of organic pasture management on the soil microbiome is important for sustainable forage production since soil microbiome diversity contributes to improved nutrient cycling, soil structure, plant growth, and environmental resiliency; however, the soil microbiome response to pasture management is largely unknown. This study assessed the soil microbial diversity, richness, and community structure following 10 years of pasture management (organic or non-organic) of the V4 region of the 16S rRNA using the Illumina MiSeq platform. Soil samples were collected from 0–15 cm in July and August from 2017–2018 and soil nutrient properties (nutrients, carbon, nitrogen, and pH) quantified and correlated with soil microbial diversity. Overall, greater soil bacterial species richness (P ≤ 0.05) occurred in organic relative to non-organic (conventional) systems. Management affected bacterial species richness (Chao1), with greater richness occurring in organic pasture soils and less richness occurring in non-organic systems (P ≤ 0.05). Similarly, management affected bacterial evenness (Simpson’s index), with a more diverse community occurring in organically managed soils relative to non-organic pastures (P ≤ 0.05). Linear discriminant analysis effect size analysis showed statistically significant and biologically consistent differences in bacterial taxa in organic compared with non-organic soils. Therefore, there was a shift in bacterial community structure in organic relative to non-organic soils (P ≤ 0.05). Additionally, soil nutrients (Fe, Mg, Ni, S, Al, K, Cd, and Cu), pH, C, and N were correlated with one or more dominant bacterial phyla (Gemmatimonadetes, Planctomycetes, Firmicutes, Chloroflexi, Actinobacteria, and Acidobacteria). Overall, pasture management affected soil microbial diversity, with greater diversity occurring in organic than non-organic systems, likely owing to applications of organic poultry litter in organic systems compared to non-organic management (use of inorganic-fertilizers and herbicides). Results indicate that when pastures are converted to organic production systems, soil microbial richness and diversity may increase, thereby resulting in enhanced soil microbiome diversity and overall ecosystem services.

【 授权许可】

CC BY