Location: Forage Seed and Cereal Research
Project Number: 2072-12620-001-09-I
Project Type: Interagency Reimbursable Agreement
Start Date: Jul 1, 2018
End Date: Jun 30, 2020
The primary objective of this study is to determine if biochar applications to vineyard soils can reduce the overall amount of pesticides that accumulate in grapes and in finished wines. The widespread presence of pesticides in wines has prompted vineyards to seek and employ sustainable practices that reduce pesticide use. However, even under management practices that reduce the use of foliar pesticides, most vineyards continue to employ weed management strategies that draw on a small arsenal of potent herbicides. Regular application of common pesticides results in not only the accumulation of pesticides in soil, but also translocation of pesticides into plant tissues. During fermentation, these pesticides can be concentrated, resulting in finished wines that have trace amounts of pesticide residue. Although the concentration of these pesticides is likely within the maximum concentration levels established by the Environmental Protection Agency for drinking water, the public perception that wine may be contaminated with pesticides drives consumers to purchase organic wines. Biochar, a carbon-rich soil amendment, has previously been shown to sorb herbicides like glyphosate. Because glyphosate is commonly used in vineyards to control weeds, we wondered if biochar could be employed to retain glyphosate in the soil and prevent translocation into plant materials. The proposed research aims to 1) determine if wine produced from biochar-amended grapevines contains less pesticide residues and 2) educates growers about the potential environmental and agronomic benefits of using vineyard residues to produce biochar.
We will pursue a five step research approach: 1) Develop protocols to detect and quantify the concentrations of common herbicides in commercially available wines. 2) Screen a biochar library to identify which biochar can best bind common herbicides by using a synthetic precipitation leaching protocol. 3) Initiate field study on established grape plantings. In this study we will compare herbicide concentrations in grapes grown on plantings grown in biochar-amended soil to those grown in unamended soils. Grape quality and yield will be measured, as will yeast-available nutrients, herbicide concentration, and ergosterol content. 4) Produce micro-fermentations of wine. 5) Evaluate micro-fermentation for herbicide concentration and ergosterol content. Additionally, curriculum will be developed and disseminated regarding the production and potential benefits of biochar from vineyard residues.