Department of Agricultural Microbiology, College of Agriculture, Kerala Agricultural University, Vellanikkara, Thrissur, Kerala, India.
Department of Soil Science, KSCSTE - Kerala Forest Research Institute, Peechi, Thrissur, Kerala, India.
Environ Sci Pollut Res Int. 2024 Sep;31(44):56236-56252. doi: 10.1007/s11356-024-34850-1. Epub 2024 Sep 12.
This study investigates the diversity and composition of soil bacterial communities in the rhizosphere of Attapadi and Nelliyampathy, prominent hill stations in Palakkad district, Kerala, India. The persistent flooding and landslides in 2018 and 2019 significantly impacted agricultural productivity in these regions. Utilizing high-throughput 16S rRNA gene sequencing (Illumina MiSeq), we conducted a comprehensive analysis of soil samples. Correlative assessments between soil parameters and microbial relative abundance at the phylum level revealed noteworthy positive associations. Notably, nitrogen (N) exhibited a positive relation with Crenarchaeota, Chloroflexi, Actinobacteriota, and Acidobacteriota; pH correlated with Firmicutes; organic carbon (OC) with WPS-2; and phosphorous with Proteobacteria. A total of 31,402 operational taxonomic units (OTUs) were identified, with the highest feature counts observed in undisturbed soils from Attapadi (AUD) and Nelliyampathy (NUD) (13,007 and 12,915, respectively). Disturbed soils in Nelliyampathy (ND) and Attapadi (AD) displayed a substantial decline in microbial diversity and composition, harbouring 1409 and 4071 OTUs, respectively. Alpha and beta diversity indices further underscored the more severe impairment of ND soils compared to AD soils. Interestingly, a majority of ND samples were landslide-affected (four out of five), while flood-affected soils accounted for four out of six AD samples. This indicates that landslides exert a more pronounced impact on microbial diversity and composition than floods. The observed decline in microbial count, composition, and diversity, even after 2 years of the disaster, raises concerns about potential threats to agricultural output. The findings emphasize the need for corrective measures, including the incorporation of microbial inoculum, to restore soil fertility in post-disaster landscapes.
本研究调查了印度喀拉拉邦帕拉卡德地区著名的高山度假胜地阿塔帕迪和内利扬帕蒂的根际土壤细菌群落的多样性和组成。2018 年和 2019 年的持续洪水和山体滑坡对这些地区的农业生产力产生了重大影响。利用高通量 16S rRNA 基因测序（Illumina MiSeq），我们对土壤样本进行了全面分析。土壤参数与门水平微生物相对丰度的相关性评估显示出显著的正相关关系。值得注意的是，氮（N）与 Crenarchaeota、Chloroflexi、Actinobacteriota 和 Acidobacteriota 呈正相关；pH 与Firmicutes 相关；有机碳（OC）与 WPS-2 相关；磷与 Proteobacteria 相关。共鉴定出 31,402 个操作分类单元（OTUs），其中阿塔帕迪（AUD）和内利扬帕蒂（NUD）未扰动土壤的特征计数最高（分别为 13,007 和 12,915）。内利扬帕蒂（ND）和阿塔帕迪（AD）的扰动土壤的微生物多样性和组成显著下降，分别含有 1409 和 4071 个 OTUs。alpha 和 beta 多样性指数进一步强调了 ND 土壤比 AD 土壤受到更严重的破坏。有趣的是，ND 样本大多受到山体滑坡的影响（五个中的四个），而 AD 样本中四个受到洪水的影响。这表明山体滑坡对微生物多样性和组成的影响比洪水更为显著。即使在灾难发生两年后，微生物数量、组成和多样性的下降仍然令人担忧，这可能对农业产出构成潜在威胁。这些发现强调了需要采取纠正措施，包括引入微生物接种剂，以恢复灾后景观的土壤肥力。
