title: Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture.
abstract: Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated €15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture.
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, Gent, 9000, Belgium.|Peltracom, Skaldenstraat 7a, Desteldonk, 9042, Belgium.
authors.forename: Oliver
authors.initials: O
authors.lastname: Grunert
authors.affiliation: Department of Plant Production, Ghent University, Coupure Links 653, Gent, 9000, Belgium.
authors.forename: Dirk
authors.initials: D
authors.lastname: Reheul
authors.affiliation: Department of Plant Production, Ghent University, Coupure Links 653, Gent, 9000, Belgium.
authors.forename: Marie-Christine
authors.initials: MC
authors.lastname: Van Labeke
authors.affiliation: Peltracom, Skaldenstraat 7a, Desteldonk, 9042, Belgium.
authors.forename: Maaike
authors.initials: M
authors.lastname: Perneel
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, Gent, 9000, Belgium.
authors.forename: Emma
authors.initials: E
authors.lastname: Hernandez-Sanabria
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, Gent, 9000, Belgium.|Research Group of Sustainable Energy, Air and Water Technology, Department of Bioscience Engineering, University of Antwerp, Groenenborgerlaan 171, Antwerpen, 2020, Belgium.
authors.forename: Siegfried E
authors.initials: SE
authors.lastname: Vlaeminck
authors.affiliation: Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, Gent, 9000, Belgium.
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
mesh_terms: D000383:Agriculture / Q000379:methods; D002245:Carbon Dioxide / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry*; D005308:Fertilizers; D009584:Nitrogen / Q000378:metabolism*; D012988:Soil Microbiology
chemical_list: D003470:Culture Media; D005308:Fertilizers; D002245:Carbon Dioxide; D009584:Nitrogen