High-throughput sequencing analysis based on nematode indices revealed healthier soils of organic vineyards
Proper soil health assessments are crucial for sustainable cropland. Among the widely employed approaches, evaluating nematode community structure is particularly suitable. Traditionally, the taxonomic characterization of soil nematodes has relied on time-consuming morphology-based methods requiring experienced experts. However, molecular tools like high-throughput sequencing have emerged as efficient alternatives. In this study, we performed a metataxonomic analysis of soil samples collected from 57 vineyards in the DOCa Rioja region of Northern Spain, focusing on the impact of organic viticulture and cover cropping compared to integrated pest management (IPM) and tilling practices. Our goal was to investigate the potential benefits of organic viticulture and cover cropping on the quality and biodiversity of vineyard soils. The soil samples were collected to a depth of 20 cm, and the vineyards were categorized based on their pest and soil management strategies. Employing specific primers and following the Illumina amplicon protocol, we conducted sequencing on the Illumina MiSeq platform (2×300 bp). The resulting data underwent bioinformatics analysis utilizing Qiime2 and the SILVA v138.1 database to explore biodiversity measures and differentially abundant taxa. Over 80 taxonomic groups (genus/family) of nematodes were identified and utilized for calculating nematode-based indices using the NINJA platform. Findings showed no significant differences between cover cropping and tilling practices but for pest management. Thus, organic viticulture increased the α-biodiversity of soil nematodes, and nematode-based indices revealed raised environmental disturbance, higher occurrence of plant-parasitic nematodes of adverse implications for crop health, and declined soil food web structure in IPM vineyards. In conclusion, this approach appears well suited to assess vineyard soil health.
Issue: ICGWS 2023
1 Instituto de Ciencias de la Vid y del Vino (CSIC-Univ. de La Rioja-Gobierno de La Rioja), Logroño, Spain.
2 Centro de Investigación Biomédica de La Rioja (CIBIR), Logroño, Spain.
3 Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain.
4 Universidad Rey Juan Carlos, Madrid, Spain.