The aim of this project was to investigate the effect of compost application on soil fertility, above and below ground vine growth, yield and grape quality in a commercial vineyard in Italy. Two different types of compost (compost from vine pruning waste and from cattle manure) was applied in two ways (inter-row and under-vine) in a mature Cabernet Sauvignon block over five years.
Long term addition of compost to a vineyard could be beneficial to soil properties, including organic matter and microbial biomass;
- Compost from vine pruning waste had the strongest stimulative effect on root growth, especially when applied under-vine. Compost from cattle manure did not significantly affect root growth.
- Application of cattle manure compost, inter-row stimulated the most vegetative growth;
- Over five years, under-vine application of pruning waste compost increased vegetative growth while inter-row application of pruning waste compost had no significant effect on vegetative growth;
- All treatments showed an increase in yield through more bunches and higher bunch weights, without affecting berry weight;
- Inter-row manure and under-vine pruning waste composts showed a reduction in total soluble solids, total anthocyanins and flavonoids, probably because of the respective increased vegetative growth and root density in these treatments that competed with bunches for nutrients;
- The best results were obtained with inter-row application of pruning waste compost. It promoted well-balanced root/canopy growth, favouring a balanced allocation of nutrients between these organs and the grapes and recorded an increased yield without negative effects on grape quality.
Significance of the study
This study provides insights into improving organic nutrient management practices in the vineyard. Application of compost can be beneficial, but application rates, origin and chemical composition of compost as well as application method should be taken into consideration when compost is applied.
Federica Gaiotti, Patrick Marcuzzo, Nicola Belfiore, Lorenzo Lovat, Flavio Fornasier and Diego Tomasi