Since the 1960s, American grape growers have followed a set of nutrient management guidelines that have often entailed more guess-work than precise strategies. That could change thanks to an industry-driven project led by Washington State University’s Markus Keller.
“We want to reassess the way we approach nutrient management,” said Keller, WSU’s Chateau Ste. Michelle Distinguished Professor in Viticulture.
Historically, growers have relied on a one-size-fits-all method of managing nutrients, delivering the same amount of fertilizer to an entire vineyard block. That is because assessing the nutrient status of individual plants or even sections of a vineyard by conventional methods is both impractical and costly.
“While much of the crop receives the right amount of fertilizer, sections or individual plants may receive too much or too little,” Keller said.
By using remote sensors on drones or airplanes, and other technologies, Keller’s team hopes to identify hitherto hard-to-detect nutrient surpluses or deficiencies in a timely manner, so that growers can make more nimble management decisions.
“Right now, leaf analysis can take up to a couple of weeks,” he said. “By the time the grower gets the results, it is often too late to correct any inadequacies in that particular plant or part of the vineyard.”
Soil sampling can be even more problematic. Soil in one block of a vineyard can vary tremendously across the block and can be very different nutrient-wise from another.
“Plants are also very selective about what they take from the soil,” Keller said.
Conventional methods are still important tools for the grower and industry, and this new research seeks to supplement rather than replace some of these more standard practices. The more resources and data growers have, the more efficient and productive their vineyards become. That benefits more than just growers.
“This kind of approach could go a long way in helping the environment, too, by reducing the amount of fertilizers being used, and by applying them at the right time in the right place” Keller said.
Consumers may benefit, too. In addition to the potential cost savings passed down in wine sales, consumers could also see an improvement to the quality of their wines.
“Sometimes when you open a Syrah, there can be an initial off-putting smell, so you have to give it some time to breathe,” Keller added. “It’s possible that the odor could stem from an issue with nitrogen, which is something we could target.”
Beyond reassessing the conventional guidelines of nutrient management, one of Keller’s goals is to share these new methods with as many growers as possible.
“There’s an important Extension component to this project,” he said. “In addition to providing training to growers around the country, we want to develop apps and other decision-support tools to better equip growers as they form and augment their nutrient management plans.”
The project also includes juice, table, and raisin grapes along with wine grapes, covering 97 percent of U.S. grape production regions.
“We want all grape growers to benefit from this research,” Keller said.
Boon for WSU
Funded by the USDA’s National Institute of Food and Agriculture, the project is a collaborative effort between WSU and Cornell, UC Davis, Oregon State, Rochester Institute of Technology, Virginia Tech, and USDA-ARS. The total grant is $4.75 million, of which the first $1 million has been approved. Subsequent installments of the grant will be contingent on the project’s progress.
The National Grape Research Alliance, an industry-driven, nonprofit organization that aligns research priorities to strengthen the competitiveness of America’s grape industry originally conceived of the project that launches Sept. 30.
“Given the prestige of all the institutions involved, it is a great honor to have been asked by the NGRA to lead such an exciting and dynamic project,” Keller said.
Including Keller, the WSU research team consists of Qin Zhang and Manoj Karkee, both of WSU’s Center for Precision and Automated Agricultural Systems (CPAAS), as well as Jim Harbertson of WSU’s Wine Science Center. Each faculty member will also have one doctoral student working on the project.
A project of this scale and scope involving so many institutions requires significant coordination and a host of key partners across the country. Financial support in Washington state for the project comes from the Washington State Grape and Wine Research Program, and the Washington State Concord Grape Research Council.
Industry leaders are also playing an active role, with many serving on a project advisory panel. Among the notable advisors are representatives from the Washington State Wine Commission, National Grape Co-op/Welch’s, E & J Gallo Winery, Ste. Michelle Wine Estates, and Sun-Maid Growers of California. In Washington state alone, Ste. Michelle Wine Estates has allotted three vineyards to the research project, and a Concord grower has dedicated a vineyard to the project as well.
“This has been industry-driven from its earliest conception, and continues to be,” Keller said. “With so many partners and institutions involved, it’s very exciting for all of us, and for WSU, too.” — By Brandon Schrand, WSU College of Agricultural, Human & Natural Resource Sciences