The weak role of organic mulches in shaping bacterial communities in grapevine
The interest in sustainable and ecologic agricultural practices in grapevine has grown significantly in recent years in the context of ecological transition. Organic mulches are treatments that support the circular economy and positively affect the soil and the plant. They are an alternative to herbicides and other conventional practices since they may influence soil moisture, erosion, structure and weed control. However, their effects on the soil and must microbiota remain unknown. Understanding the relationship between vineyard management and soil and plant microbiota may help to choose the optimal practices, reducing environmental impact and improving wine quality. We aimed to evaluate the effects of five soil management treatments on soil and must bacterial communities along three consecutive years using next-generation sequencing (NGS) techniques. The study was performed in two vineyards of the same region (La Rioja, Spain). Two conventional treatments (Herbicide use and Under-row Tillage) were compared with three organic mulches applied on the vine row (Grapevine Pruning Debris, Spent Mushrooms Compost and Straw). The main factors affecting the soil bacterial community were year followed by location. The treatment effect on soil microbiota was weak and could only be found when analyzing each year and location individually. In particular, the bacterial communities of the conventional practices clustered in all years and locations. However, organic mulches were only grouped in the third year of study at both locations. Besides, the treatments did not affect the must bacterial communities and were driven by year and location. These results show that the practices have a weak effect compared to year or location and that their impact is detected in the soil but not in the must. Therefore, organic mulches could be a sustainable viticulture alternative. Moreover, the organic mulch effect has been enhanced over the years and farmers should use it in the long term.
Issue: ICGWS 2023
1Instituto de Ciencias de la Vid y del Vino, CSIC, Gobierno de la Rioja, Universidad de La Rioja, 26006 Logroño, Spain
2Faculty of Health Sciences, Valencian International University, 46002 Valencia, Spain
3Centro de Investigación Biomédica de La Rioja (CIBIR), 26006, Logroño, Spain