Organic vineyards in Rioja show greater soil health and resilience through diverse nematode communities, study finds

A recent study conducted in the Rioja wine region of Spain has provided new insights into the health of vineyard soils by analyzing nematode communities using advanced DNA metabarcoding techniques. The research, carried out across 57 vineyards in the Denominación de Origen Calificada (DOCa) Rioja, focused on understanding how different vineyard management practices affect soil biodiversity and ecosystem resilience.

The team, made up of scientists from the Instituto de Ciencias de la Vid y el Vino (ICVV), CIBIR, MBG-CSIC, INIA-CSIC, and Universidad Rey Juan Carlos, used high-throughput sequencing technology (Illumina MiSeq) to identify 114 different nematode taxa from soil samples. Nematodes are microscopic roundworms that play a key role in nutrient cycling and are present at all levels of the soil food web. Their sensitivity to environmental changes makes them valuable bioindicators for soil health.

The study found that organic vineyards supported more diverse and complex nematode communities compared to conventionally managed sites. These organic plots had a higher proportion of predatory and omnivorous nematodes, which are considered indicators of stable and mature ecosystems. The researchers also observed that the networks of interactions among nematode species were more connected in organic soils, suggesting greater resilience to disturbances such as drought or disease.

In contrast, alternative practices like using cover crops instead of tillage showed only limited effects on nematode diversity and community structure. While these methods are often promoted for their environmental benefits, the data suggest that they may not be as effective as full organic management in promoting soil biodiversity.

The use of DNA metabarcoding allowed the researchers to detect both harmful plant-parasitic nematodes and beneficial entomopathogenic species with high precision. This approach also enabled them to calculate functional indicators related to the trophic structure of the soil ecosystem, providing a detailed picture of how management practices influence soil health.

The findings highlight the potential of DNA-based monitoring as a practical tool for assessing ecological impacts in vineyards and other agricultural systems. By offering a sensitive and high-resolution method for tracking changes in soil communities, this technology could help guide sustainable farming decisions.

The project received funding from several Spanish research agencies and programs, including MCIN/AEI, NextGenerationEU/PRTR, the Government of La Rioja, and the Instituto de Estudios Riojanos. The full results are published in the journal Ecological Indicators under the title “Metabarcoding-based characterization of soil nematode communities to assess soil health in viticulture.”

This research comes at a time when sustainable agriculture is increasingly important for both environmental protection and long-term productivity. As vineyards around the world face challenges from climate change and soil degradation, tools like DNA metabarcoding may become essential for maintaining healthy soils and producing high-quality wines.