Pot Steffi, De Tender Caroline, Ommeslag Sarah, Delcour Ilse, Ceusters Johan, Gorrens Ellen, Debode Jane, Vandecasteele Bart, Vancampenhout Karen
Division Forest, Nature and Landscape, Department of Earth and Environmental Sciences, KU Leuven, Geel, Belgium.
Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), Plant Sciences Unit, Merelbeke, Belgium.
Front Microbiol. 2021 Apr 7;12:643679. doi: 10.3389/fmicb.2021.643679. eCollection 2021.
Three characteristics are considered key for optimal use of composts in growing media: maturity, pH and organic matter content. Maturation is a critical step in the processing of composts contributing to compost quality. Blending of composts with chopped heath biomass, sieving out the larger fraction of composts and acidification of composts by adding elemental sulfur may be used either to increase organic matter content or to reduce pH for a better fit in growing media. While several studies have shown the effectiveness of these treatments to improve the use of composts in growing media, the effect of these treatments on the compost microbiome has merely been assessed before. In the present study, five immature composts were allowed to mature, and were subsequently acidified, blended or sieved. Bacterial and fungal communities of the composts were characterized and quantified using 16S rRNA and ITS2 gene metabarcoding and phospholipid fatty acid analysis. Metabolic biodiversity and activity were analyzed using Biolog EcoPlates. Compost batch was shown to be more important than maturation or optimization treatments to determine the compost microbiome. Compost maturation increased microbial diversity and favored beneficial microorganisms, which may be positive for the use of composts in growing media. Blending of composts increased microbial diversity, metabolic diversity, and metabolic activity, which may have a positive effect in growing media. Blending may be used to modify the microbiome to a certain degree in order to optimize microbiological characteristics. Acidification caused a decrease in bacterial diversity and microbial activity, which may be negative for the use in growing media, although the changes are limited. Sieving had limited effect on the microbiome of composts. Because of the limited effect on the microbiome, sieving of composts may be used flexible to improve (bio)chemical characteristics. This is the first study to assess the effects of maturation and optimization treatments to either increase organic matter content or lower pH in composts on the compost microbiome.
在生长介质中最佳使用堆肥时，有三个特性被认为是关键的：成熟度、pH值和有机质含量。成熟是堆肥处理过程中的关键步骤，对堆肥质量有影响。将堆肥与切碎的石南生物质混合、筛分出较大颗粒的堆肥以及通过添加元素硫对堆肥进行酸化处理，既可以用来增加有机质含量，也可以降低pH值，以便更好地适用于生长介质。虽然多项研究表明这些处理方法在改善生长介质中堆肥使用效果方面是有效的，但这些处理对堆肥微生物群落的影响此前仅得到过评估。在本研究中，让五种未成熟的堆肥进行成熟处理，随后进行酸化、混合或筛分。使用16S rRNA和ITS2基因宏条形码技术以及磷脂脂肪酸分析对堆肥的细菌和真菌群落进行表征和定量。使用Biolog生态板分析代谢生物多样性和活性。结果表明，对于确定堆肥微生物群落而言，堆肥批次比成熟或优化处理更为重要。堆肥成熟增加了微生物多样性，并有利于有益微生物的生长，这对于在生长介质中使用堆肥可能是积极的。堆肥混合增加了微生物多样性、代谢多样性和代谢活性，这可能对生长介质有积极影响。混合可用于在一定程度上改变微生物群落，以优化微生物特性。酸化导致细菌多样性和微生物活性下降，这对于在生长介质中的使用可能是负面的，尽管变化有限。筛分对堆肥微生物群落的影响有限。由于对微生物群落的影响有限，堆肥筛分可灵活用于改善（生物）化学特性。这是第一项评估通过增加堆肥中有机质含量或降低pH值的成熟和优化处理对堆肥微生物群落影响的研究。
