AUTHOR=Song Xiaotong , Liu Jiayi , Feng Yanzhang , Zhou Chengxu , Li Xiaohui , Yan Xiaojun , Ruan Roger , Cheng Pengfei 

TITLE=Microalgae-based biofertilizers improve fertility and microbial community structures in the soil of potted tomato

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1461945

DOI=10.3389/fpls.2024.1461945

ISSN=1664-462X

ABSTRACT=<p>Continuous cropping decreases soil nutrients and destroys microbial community structure, so the development of eco-friendly and effective biofertilizers is necessary under present conditions. In this study, the preserving microalgal strain <italic>Tribonema</italic> sp. (H) was firstly selected to be combined with agroforestry waste (shell powder, straw fermentation liquid) and the agroforestry microorganism <italic>Bacillus</italic> sp. to form microalgae-based fertilizers for the continuous cropping soil of potted tomato. Compared to the control (CK), microalgae-based fertilizers (concentration: 4.45 × 10<sup>6</sup> cells/ml, dosage: 20 ml/day) improved soil nutrients and salinization indicators. Specifically, the combination of <italic>Tribonema</italic> sp. and shell powder (HB) reduced electrical conductivity (EC) by 33.7% and significantly increased the Ca<sup>2+</sup> content by 59.4%; <italic>Tribonema</italic> sp. and <italic>Bacillus</italic> sp. (HY) improved the effects of available phosphorous (AP), DOC, DON, NH<sub>4</sub><sup>+</sup>-N, NO<sub>3</sub><sup>−</sup>-N, and Mg<sup>2+</sup> in the soil by 27.4%, 231.3%, 403.4%, 125.2%, 215.6%, and 73.4%, respectively. Microalgae-based fertilizers alter the abundance of soil bacteria and fungi, causing beneficial bacteria such as <italic>Thermonaerobaculia</italic>, <italic>Subgroup_10</italic>, <italic>Sordariomycetes</italic>, and <italic>Microascaceae</italic> to increase, while pathogenic bacteria like <italic>Pseudomonas</italic>, <italic>Togniniaceae</italic>, and <italic>Phaeoacremonium</italic> decreased. Combining microalgae with agroforestry wastes as a biofertilizer is promising to improve the microbial community structure of the soil with continuous cropping, which will aid in the increase of tomato production and promote green agricultural development.</p>