Executive Summary: The Oasis Vineyard Trial was initiated in 2016 to study how biochar and compost treatments impact soil water potential, vine growth, and harvest yields in a newly planted vineyard. This vineyard, managed by Monterey Pacific, Inc., is located outside of King City, CA in the Salinas Valley. This field research project, funded by the California Department of Water Resources (DWR), was administered by Sonoma Ecology Center and included support from researchers from the University of California, Riverside.
In this vineyard trial, biochar and compost treatments were applied both separately and in combination during soil preparation activities prior to planting ‘Pinot Noir’(Vitis vinifera) vines. Significant increases in harvest yield were observed for all treatments with the highest yield in the biochar treatment, resulting in a 45% increase over the control. Increased pruning weight was observed for both the compost and the compost + biochar treatments; and higher cluster counts were observed for both the biochar and the compost + biochar treatments. Though the treatments resulted in increased plant vigor and crop yield, all treatments received the same irrigation regime throughout the trial, demonstrating improved water use efficiency where soil had been amended. Results from this field research trial indicate that biochar and compost treatments can improve water use efficiency, vine growth, and harvest yields for newly planted vineyards in sandy soils. While the results presented here show preliminary trends, ongoing monitoring is needed to validate these results over successive growing seasons.