Influence of the application of mycorrhizal fungi and Bacillus amyloliquefaciens on the yields of three vegetables and a grass with organic fertilization on peat-free growing media in organic plant production

The future of plant production will be shaped by the ecologically justified renunciation of peat as part of growing media and by a steadily growing proportion of ecological production processes. We were interested how a combination of microorganisms and organic fertilizers affects yield when growing plants on peat-free growing media. We set up an experiment with a fully randomized block design in which three types of vegetables (lettuce, celery, Chinese cabbage) and a grass were grown on peat-free growing media in “Mitscherlich-vessels”. Chicken dry manure and hydrothermally carbonized sheep wool served as fertilizers. Bacillus amyloliquefaciens, mycorrhizal fungi, and Bacillus amyloliquefaciens combined with mycorrhizal fungi were selected as microorganisms. This resulted in a total of 48 vessels per plant species. With the exception of celery, all species showed high yield increases when the application of organic fertilizers was combined with the application of bacteria and/or mycorrhizal fungi. Our results suggest that a combination of microorganisms and organic fertilizers is a promising approach for increasing yields of a variety of plants, when using peat-free growing media for plant production.