Soil Carbon Sequestration Following Conservation Tillage of a Vineyard.

Abstract:

Cultivation of cover crops in the vineyard inter-row has been shown to have numerous benefits, but tests of the potential C sequestration benefits in perennial crops is limited. We investigated the impacts of three different between vine-row soil management treatments: a cover crop under minimum tillage (CC+mow); a cover crop mowed and incorporated to the soil in spring (CC+till); and a native weeds cover managed in the conventional manner (till), on root production and soil respiration (R_s) in a vineyard. Soil CO₂ flux, gravimetric water content (q_g) and total C, as well as leaf water potential, were monitored during a year. In early summer, a 1.5m deep trench per treatment was excavated, and three 15L soil samples were taken at 5 depths to determine the root distribution and total biomass. The root biomass was higher in the “CC+mow” treatment over the “till”, especially the fine roots in the topsoil layer. The conventional vine-row management showed the highest yearly CO₂ emission from R_s. The changes in the soil structure and therefore water retention resulting from the treatments, mainly in the topsoil layer, may explain the R_s differences. Our results point to conservation tillage as resource to enhance C sequestration in grapevine.