Extra-simplified eco-viticulture increases contributions of plant lignin and microbial necromass to soil organic carbon within vineyards

Abstract

Although vineyard soils are regarded as having substantial potential for carbon sequestration, the coupled relationship between conventional viticulture, the implementation of vineyard ecological management, and the resulting alterations in soil conditions and sources of soil organic carbon (SOC) remains underexplored. Accordingly, we conducted a five-year vineyard trial in Penglai, Yantai, China to compare different management practices, including traditional viticulture (TV) and extra-simplified eco-viticulture (EV) modes applied to each of Cabernet Sauvignon and Italian Riesling vineyards, with adjacent uncultivated land (CK) as a control. This study investigated the SOC content and carbon stock in soils at various depths within each sample plot, and tracked the dynamics of plant- and microbial-derived compounds using two groups of biomarkers (lignin phenols and amino sugars) along with their relative contributions to SOC. The results showed that long-term TV significantly improved the SOC pool, and based on this, the implementation of EV resulted in a further increase in SOC content and carbon stocks by 7.21–24.05 % and 10.82–30.00 %, respectively. Plant- (31–53 %) and microbial-derived carbon (30–47 %) contributed similarly to SOC in vineyards, but their contents in the EV were generally higher than those in TV. Lignin phenol accumulation was predominantly regulated by plant properties (grapevine basal diameter and grapevine biomass [GB]) and soil abiotic factors (pH, total nitrogen, total phosphorus, total potassium, etc.), while amino sugars were influenced by a smaller set of factors (grapevine root biomass, GB, pH, SOC, and microbial biomass phosphorus). GB and pH were particularly important as co-driver factors for soil carbon sequestration. Furthermore, the effect of viticulture mode on the SOC pool was most pronounced in the 0–10 cm soil depth, gradually decreasing with soil depth. In conclusion, we considered that the EV mode was a recommended practice for sustainable vineyard.