Vineyard Soil Management: The Effects of "Soil Hilling" and Straw Mulch Winter Protection Practices on Soil Temperature, Moisture, and Quality.

Viticulture, the production of grapes, requires specific soil and water management unlike many other production systems. “Soil hilling” is a common annual practice for preventing winter grapevine loss in northern vineyards, a major concern in Ohio where 2014 “polar vortex” weather conditions caused $12 million losses to Ohio vineyards. Soil is hilled over the graft union of the grapevines in the fall and removed in the spring, essentially tilling the soil twice per year. While this practice effectively protects the graft union, it has negative impacts. Straw mulch is an alternative winter protection material but has not been widely adopted. This research, conducted in the Ohio Agricultural Research and Development Center research vineyard, evaluated the efficacy of straw mulch for protecting grapevine graft unions from cold temperatures and investigated effects of straw mulch and soil hilling in vineyard rows. Temperature data show that straw mulch effectively protects the graft union from potentially damaging winter temperatures. Soil covered by straw mulch retained significantly higher volumetric water content at depths of 3.8 cm, 7.5 cm, and 12 cm during the summer. Additionally, soil physical, biological, and chemical quality indicators were tested on soil hill and straw mulch treatments to determine if the treatments increase, decrease, or have no impact on soil quality. This new knowledge will help develop new strategies to mitigate freezing damage, decrease negative soil management practices, and increase vineyard sustainability. Ultimately, the findings from this research will enhance the economic and environmental sustainability of grape production in Ohio.