Organic farming practices change the soil bacteria community, improving soil quality and maize crop yields

Ademir Durrer; Thiago Gumiere; Maurício Rumenos Guidetti Zagatto; Henrique Petry Feiler; Antonio Marcos Miranda Silva; Rodrigo Henriques Longaresi; Sérgio K Homma; Elke J B N Cardoso

doi:10.7717/peerj.11985

Organic farming practices change the soil bacteria community, improving soil quality and maize crop yields

PeerJ. 2021 Sep 23:9:e11985. doi: 10.7717/peerj.11985. eCollection 2021.

Authors

Ademir Durrer¹, Thiago Gumiere², Maurício Rumenos Guidetti Zagatto¹, Henrique Petry Feiler¹, Antonio Marcos Miranda Silva¹, Rodrigo Henriques Longaresi³, Sérgio K Homma³, Elke J B N Cardoso¹

Affiliations

¹ Soil Science Department/ Luiz de Queiroz College of Agriculture, University of São Paulo, Piracicaba, São Paulo, Brazil.
² Department of Soil and Agricultural Engineering, Laval University, Quebec City, Canada, Canada.
³ Mokiti Okada Research Center, Ipeúna, São Paulo, Brazil.

Abstract

Background: The importance of organic farming has increased through the years to promote food security allied with minimal harm to the ecosystem. Besides the environmental benefits, a recurring problem associated with organic management is the unsatisfactory yield. A possible solution may rely on the soil microbiome, which presents a crucial role in the soil system. Here, we aimed to evaluate the soil bacterial community structure and composition under organic and conventional farming, considering the tropical climate and tropical soil.

Methodology: Our organic management treatments were composed by composted poultry manure and green manure with Bokashi. Both organic treatments were based on low nitrogen inputs. We evaluated the soil bacterial community composition by high-throughput sequencing of 16S rRNA genes, soil fertility, and soil enzyme activity in two organic farming systems, one conventional and the last transitional from conventional to organic.

Results: We observed that both organic systems evaluated in this study, have higher yield than the conventional treatment, even in a year with drought conditions. These yield results are highly correlated with changes in soil chemical properties and enzymatic activity. The attributes pH, Ca, P, alkaline phosphatase, and β- glucosidase activity are positively correlated with organic systems, while K and Al are correlated with conventional treatment. Also, our results show in the organic systems the changes in the soil bacteria community, being phyla Acidobacteria, Firmicutes, Nitrospirae, and Rokubacteria the most abundant. These phyla were correlated with soil biochemical changes in the organic systems, helping to increase crop yields.

Conclusion: Different organic management systems, (the so-called natural and organic management systems, which use distinct organic sources), shift the soil bacterial community composition, implying changes in their functionalities. Also, our results contributed to the identification of target bacterial groups and changes in soil chemical properties and enzymatic activity in a trophic organic farming system, which may contribute to higher crop yields.

Keywords: Bacterial community; Bokashi; Composted poultry manure; Green manure; Nature farming; Soil enzymes; Soil management systems.

Grants and funding

Elke Jurandy Bran Nogueira Cardoso was supported by the São Paulo Research foundation –FAPESP (no. 2016/18944-3) and the Brazilian Research Council (CNPq) for the productivity grant (no. 305193/2016-3). Ademir Durrer and Maurício Rumenos Guidetti Zagatto were supported by FAPESP and CNPq, respectively with their postdoctoral scholarships (no. 2017/18994-3 and no. 153330/2018-0). Antonio Marcos Miranda Silva and Henrique Petry Feiler were supported by FAPESP and CAPES Ph.D. grants, respectively (no. 2019/13436-8 and Finance code 001). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.