Soil Carbon Sequestration Following Conservation Tillage of a Vineyard.

Friday, 19 December 2014
Maria Mar Alsina, David R Smart and Michael W Wolff, University of California Davis, Davis, CA, United States
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 (Rs) in a vineyard. Soil CO2 flux, gravimetric water content (qg) 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 Rs. The changes in the soil structure and therefore water retention resulting from the treatments, mainly in the topsoil layer, may explain the Rs differences. Our results point to conservation tillage as resource to enhance C sequestration in grapevine.