Study: Hemp Could Be Beneficial Cover Crop for Wine Vineyards

Planting hemp as a cover crop in wine vineyards could be beneficial, according to a study conducted by New Zealand researchers outlined by New Zealand Wine Grower. The research, conducted over three years in Marlborough Sauvignon Blanc vineyards by grape grower Kirsty Harkness and viticulture researcher Dr. Mark Krasnow, found the hemp did not compete with the vines and beneficially affected the soils and wines. 

Additionally, the hemp became established without supplemental irrigation during an exceptionally dry season when other cover crops failed to thrive, allowing the plants to sequester carbon longer into the season. Soils from the hemp area were also higher in organic matter and total carbon, which are beneficial for the long-term health and fertility of the soil. Differences were especially pronounced at about 16-31 inches, suggesting that hemp allows the sequestration of more carbon deeper into the soil profile than other cover crops or resident vegetation. Juice from grapes adjacent to the hemp also had greater populations of native yeasts and produced a wine of higher quality than juice from vines located far from the hemp. 

The differences in native yeast populations brought about by a hemp cover crop is an aspect sparking much interest. The suggestion that hemp could improve wine quality is an interesting further study topic, but not a path I’m currently going down. As a grape grower, my focus is on producing the highest quality fruit, and improving soil health in vineyards.” — Harkness to New Zealand Wine Grower 

Krasnow added that the hemp’s lack of competition with the vines was “a little surprising, considering how large some of the plants grew.” 

“Its ability to survive with little water, its robust root system which adds carbon to the soil, and its ability to grow in and improve compacted soils, makes it a useful tool for vineyard management,” he said.