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 fertilizers, 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BBF中添加可改善土壤物理、化学及生物肥力的微生物群落（microbial consortia）至关重要。研究人员针对三种由粪便制备的不同BBF的特性，开发了三种专属微生物群落——即生物干燥固体组分、沼液固体组分及生物炭基BBF，以促进植物生长、土壤有机质降解、固氮及磷利用效率。研究人员对BBF及土壤均进行了化学特性表征，并开展了番茄（Solanum lycopersicum cv. Minuet）的温室盆栽试验，试验中改性BBF分别作为有机氮肥或有机改良剂施用。通过一系列定量聚合酶链反应（qPCR）分析，量化了不同处理组及不同时间点下三种群落中各微生物的丰度。此外，采用扩增子（16S和ITS）高通量测序（next generation sequencing, NGS）技术表征了根际群落的动态变化。微生物活化处理与未活化处理组的植株鲜重、干重均与未处理对照组相近，且低于化学肥料对照组；而生物炭基BBF在两种处理下均实现了最高的植株重量。就番茄鲜重与干重而言，所有经微生物活化的BBF处理组的番茄重量均高于未活化处理组，且与化学肥料对照组持平或更优。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）未呈现明显变化规律。宏基因组分析显示，木霉菌属（Trichoderma）可能是提升番茄产量的核心驱动因素。在循环经济背景下，这类活化型BBF可作为合成肥料的替代方案，在降低成本、减轻环境负担的同时提升生产效益。