Effects of the application of microbiologically activated bio-based fertilizers derived from manure on tomato plants and their rhizospheric communities.

Bio-based fertilizers (BBF) recovered from animal manure are promising products to optimise resources recovery and effectively generate agricultural products. However, their soil application may be detrimental to soil fertility and it is therefore of upmost importance to enrich BBFs with microbial consortia that improve physical, chemical and biological soil fertility. Three specific microbial consortia were developed according to the characteristics of three different BBFs produced from manure (i.e. bio-dried solid fraction, solid fraction of digestate and biochar) to enhance plant growth, soil organic matter degradation, nitrogen fixation and phosphorus use efficiency. Both BBFs and soil where chemically characterized and a greenhouse pot experiment was carried out with tomato plants (Solanum lycopersicum variety Minuet) grown with the amended BBFs applied either as N-organic fertilizers or as organic amendment. An array of qPCR analyses was carried out to quantify each microorganism within the three consortia across treatments and over time. Additionally, an amplicon (16S and ITS) next generation sequencing analysis was used to characterise the development of each rhizospheric communities. Fresh and dry plant weight from both microbiologically activated and non-activated treatments showed values similar to the untreated control and lower than the chemical fertilization control, whereas biochar showed the highest plant weight for both treatments. When considering fresh and dry tomato weight, all activated BBFs showed a higher tomato weight than the non-activated treatments and similar or higher than chemical fertilization. No particular patterns were seen concerning tomatoes quality (e.g. sugar-acid ratio, taste index, carotenoids and lycopene contents). Metagenomic analysis seems to point at Trichoderma as the main driver of the positive effect on tomato yields. In the context of circular economy, these activated BBF could be used as synthetic fertilisers alternatives reducing cost, environmental burden and increasing production.

从动物粪便中回收的生物基肥料（Bio-based Fertilizer，BBF）是优化资源回收、高效生产农产品的极具潜力的产品。然而，将其施用于土壤可能会对土壤肥力产生不利影响，因此，向生物基肥料中添加可改善土壤物理、化学及生物学肥力的微生物联合体，是至关重要的举措。研究人员针对粪便源制得的三种不同生物基肥料（即生物干燥固体组分、厌氧消化固体组分及生物炭），开发了三组特定的微生物联合体，以促进植物生长、土壤有机质降解、固氮及磷利用效率提升。研究人员对所有生物基肥料及土壤进行了化学特性表征，并开展了番茄盆栽温室试验：试验以番茄（Solanum lycopersicum 品种‘Minuet’）为供试作物，将改性后的生物基肥料分别作为氮源有机肥料或有机改良剂施加。通过一系列定量聚合酶链反应（qPCR）分析，对不同处理组及不同时间点下三组微生物联合体中的各类微生物进行了定量检测。此外，通过扩增子（16S与ITS）高通量测序分析，对根际微生物群落的动态变化进行了表征。微生物活化与未活化处理组的番茄植株鲜重与干重均与空白对照组相近，且低于化学肥料对照组；而生物炭处理组在两种施加方式下均获得了最高的植株生物量。就番茄鲜重与干重而言，所有经微生物活化的生物基肥料处理组的番茄生物量均高于未活化处理组，且与化学肥料对照组相当甚至更高。番茄品质指标（如糖酸比、风味指数、类胡萝卜素及番茄红素含量）未呈现显著的变化规律。宏基因组分析结果显示，木霉菌属（Trichoderma）可能是提升番茄产量的核心驱动因子。在循环经济背景下，此类经微生物活化的生物基肥料可作为合成肥料的替代产品，在降低成本、减轻环境负荷的同时提升农产品产量。