Sponsoring Institution
National Institute of Food and Agriculture
Project Status
Funding Source
Reporting Frequency
Accession No.
Grant No.
Project No.
Proposal No.
Multistate No.
Program Code
Project Start Date
Sep 30, 2020
Project End Date
Sep 29, 2024
Grant Year
Project Director
Keller, M.
Recipient Organization
PULLMAN,WA 99164-0001
Performing Department
Non Technical Summary
This Coordinated Agricultural Project in the SCRI focus areas Plant Production and Production Efficiency (50%) and Technology (50%) seeks to enable grape growers to make data-driven nutrient-management decisions for spatially heterogenous vineyards and diverse production markets. We propose to develop grower-friendly decision-aid tools for vineyard nutrient management to optimize inputs and business profitability via improved vineyard productivity and fruit and product quality, while minimizing adverse impacts on the environment. The tools-- remote sensors that determine grapevine macronutrient and micronutrient status coupled with modern plant tissue sampling protocols--would give growers near real-time in-field access to spatial and temporal metrics for vine nutrition variability. Importantly, these tools would enable growers to act upon these measures via variable rate synthetic or organic fertilizer application. Crop yield and quality impacts for all grape sectors--fresh, wine, juice, raisins--would be included. Thus the project objectives are to 1) develop non-destructive, near-real-time tools to determine grapevine nutrient status across entire vineyards; 2) determine efficiency and suitability of precision vineyard nutrient management; 3) define grapevine nutrient ranges based on environment and production market; and 4) estimate economic impact and feasibility of vineyard nutrient management, extend knowledge to stakeholders, and advance understanding of grower decision making. Anticipated project deliverables include 1) non-destructive sensing tools to measure vine nutrient status; 2) more precise, region-specific plant tissue sampling procedures and guidelines for more precise nutrient management; and 3) website and durable extension publications outlining best nutrient management practices and economic impact of improved nutrient management and sustainability.
Animal Health Component
Research Effort Categories

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
Goals / Objectives
Grapes are grown on almost 1 million (M) acres and have a combined production value of about $6.6 billion in the US ( In 2018, US production exceeded 7.5M tons, with 4.7M tons used for wine, 1.2M tons for raisins, 1.1M tons for fresh market, and 0.5M tons for juice. Regardless of grape market or production region, vineyard nutrient management is critical to sustainably reach product-specific quality standards. While non-destructive nutrient sensing tools exist for grain crops, their adaptability to grapevines has not been studied. Despite the advancement of agricultural sensors to detect various aspects of crop status, there is no means of non-destructively measuring mineral nutrient status in grapevines. In addition, the current, basic tissue sampling protocols lack precision or relevancy for the diverse production goals of the grape industry. The standard practice is for growers to manually collect leaves or petioles once or twice during a growing season, combine them into a single sample for vineyard blocks of up to 50 acres, and mail the samples to a lab for analysis. This situation results in significant management inefficiencies, sub-optimal crop quality, and adverse environmental impacts, all of which could be avoided with near-real-time sensing tools and improved vineyard nutrition guidelines that this project seeks to develop. The project objectives are to:1) Develop non-destructive tools to measure grapevine nutrient status;2) Determine the efficiency and suitability of precision vineyard nutrient management;3) Define grapevine nutrient thresholds based on environment and production market;4) Estimate economic impact and feasibility of nutrient management decisions, extend knowledge to stakeholders, and advance understanding of grower decision making.
Project Methods
This Coordinated Agricultural Project consists of four Objectives that will be pursued to achieve our overall project goal. Objectives are broken down into Tasks that will be distributed between investigators at six universities and two federal research laboratories. Each Objective will be completed by an intersecting set of key personnel that comprise a Focus Group. Each group will be led by a Co-PD who will be responsible for integrating activities with those of other Focus Groups. Project participants will interact through emails, monthly conference calls, and annual project meetings with the Project Advisory Panel.Objective 1 - Sensors/Engineering: This objective will determine the usability and adoptability of existing sensor products for use in the detection of nutrient status (N, P, K, Mg, etc.), ideally before deficiency symptoms become apparent, in grapevines.A key element of our approach is to advance from oversampled, high-cost, high-spectral-resolution sensing toward a set of targeted wavelengths that growers can implement in a cost-effective manner, at high accuracy and precision. Both over-the-row and aerial platforms will be developed that provide grapevine nutrient status in near-real-time and at high spatial/temporal resolution across spatially heterogenous vineyards.Objective 2 - Precision Management: The project will generate vineyard nutrient maps from the sensor data collected in Objective 1 and integrate them with soil, canopy, and yield maps. These maps will enable 1) testing spatially-guided sampling protocols to reduce grower time and effort; and 2) creating fertilizer application maps, using data fusion and spatial statistics. Variable-rate applications of synthetic or organic fertilizers wil then be evaluated to develop best-practice recommendations for high-resolution vineyard nutrient management. Local variogram kriging of all spatial data, including new nutrient sensor data, will be used to predict sensor measurements to a common vineyard grid to investigate relationships between data layers.Objective 3 - Plant Nutrition/Product Quality: Nutrient supply will be manipulated in both commercial vineyard trials and pot experiments to 1) ground-truth and validate sensor technology and precision management approaches developed in Objectives 1 and 2; and 2) optimize tissue sampling and define nutrient ranges and thresholds that impact plant productivity and fruit quality for each grape market. Vine productivity and pre- and postharvest product quality will be assessed, and results will be integrated into Objectives 2 and 4. Multi-year nutrient supply studies will be conducted in five states (California, New York, Oregon, Virginia, Washington), employing multiple varieties of wine, table, raisin, and juice grapes typical for each region to accomplish these goals. Additional field trials will be conducted by the project collaborator in Argentina (Mendoza region), where Mg deficiency is particularly prevalent. To ensure these new methods will be readily adoptable if successful, spatial sampling protocols described in Objective 2 will be applied to these datasets.Objective 4 - Social Science/Extension: Using data from Objectives 2 and 3, economic impacts of vineyard nutrient management will be evaluated and economic feasibility models will be developed for improved nutrient management plans. Working with extension leaders and other stakeholders across the US to connect with growers and processers will help to identify factors that influence their nutrient management decision making. Stakeholder feedback from surveys and regional technical meetings will be used to refine project focus and translate current and project-generated information into educational products and programs. Efforts will be conducted at the local to national scale through the National Viticulture and Enology Extension Leadership group, a working group of extension professionals across the US grape production regions, in collaboration with the National Grape Research Alliance.Experimental designs will vary greatly depending on the type of experiment being proposed. Field trial design and analysis will follow the guide for on-farm vineyard trials published by the PD and collaborators. In general, results from replicated and repeated (over space and/or time) field and pot experiments conducted in Objectives 1-3 will be analyzed using appropriate ANOVA procedures using factorial designs to test interactions of treatment factors and/or repeated measures analysis where required. Standard post-hoc means separation statistical analyses will be conducted on response variables. Correlation analysis will be used to test associations between key plant response variables, and between weather-related variables and plant responses. For design, operation and installation of electronic equipment and sensors, Objectives 1 and 2 will use the standards published by the American Society of Agricultural and Biological Engineers ( Downsizing of high-resolution spectral data to operational solutions for nutrient assessment will follow advanced high independent-to-dependent variable ratio approaches. For electronic data storage Objectives 1 and 2 will use and adapt the standards developed by the International Consortium for Agricultural Systems Applications and distributed by the DSSAT Foundation (

Progress 09/30/20 to 09/29/21

Target Audience:Grape growers, crop consultants, vineyard management companies, winemakers, extension specialists Changes/Problems:A separate progress report for year 1, and a continuation proposal for years 2-4 of this project, will be submitted to NIFA. What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Several grower presentations were given about this ongoing project: Bates T. Vineyard nutrition update and variable-rate management. Lake Erie Grape Program Grower Meeting. June 23, 2021. Bates T. and Walter-Peterson H. MyEfficientVineyard software for precision viticulture. Finger Lakes Grape Program Grower Meeting. June 22, 2021. Bates T. Leveraging sensor information for variable rate vineyard management. ASEV-NGRA Precision Viticulture Symposium. June 21, 2021. Pourreza A. Monitoring grapevine nitrogen status by aerial and ground spectral sensing. ASEV-NGRA Precision Viticulture Symposium. June 21, 2021. Pourreza A. Identification of nitrogen deficiency in table grape by spectral sensing. CalPoly College of Agriculture Seminar. February 26, 2021. Pourreza A. High resolution nitrogen monitoring in vineyards. California Plant and Soil Conference. February 1, 2021. Pourreza A. Remote sensing to monitor grapevine nutrient status. San Joaquin Valley Virtual Grape Symposium. December 16, 2020. Schreiner R.P. Grapevine nutrition: requirements, tissue tests and mycorrhizas. Penn State and Cornell Universities - Vineyard Outreach Webinar Series. January 20, 2021. Stories about the project, based on interviews with project team members, appeared in the following outlets: Flyby for fertilizer (by K. Prengaman). Good Fruit Grower 71: 60-65 (2020). (September issue) What do you plan to do during the next reporting period to accomplish the goals?There are no changes to the agency-approved plan for the work proposed in Objectives 1-3. However, the review panel perceived the socioeconomic studies proposed in Objective 4 as being underdeveloped and poorly integrated with the scientific aims of the proposal. Consequently, some changes have already been made and continue to be made to address these concerns. Specifically, Co-PI James Watson stepped down and was replaced with John Woodill whose training is in economics as well as computer and information science. The project focus group Social Science/Extension, with input from our Project Advisory Panel, has already completed a survey of the wine, table, raisin and juice grape industries across the US to establish a baseline of current vineyard nutrient management practices and use of technologies with a focus on what, how, and why practices are being used in vineyards. Outreach efforts will increase as research results are generated within the project. A podcast series is being planned for production during the second half of 2021 and release in 2022 and beyond. Content will continue to be generated and shared with industry and the public through the social media outlets and the project website. We will develop "train the trainer" programs and products (publications, resources) for nationwide extension faculty in 2023 and carry out through 2024 to help guide standard practices for nutrient assessment across regions and grape markets, and share new methodologies and technologies developed from the project. We will develop two decision-support tools that may ultimately be merged into a single tool. A mapping tool will include sensor-based plant status maps with per-vine precision (Objective 1) and a method for defining management zones. These zones can be used as a prescription map for variable rate nutrient application (Objective 2) and directed sampling (Objective 3). A prototype mapping tool has been shared with a cooperating grower for testing during 2021. An economic tool will allow growers to input nutrient readings from the sensors (or automatically) at a given time during the growing season. Using this real-time data along with training data from Objectives 1-3 and results from our economic models (Objective 4), the tool can provide information about a vineyard's current nutrient status. The tool will then project out yield or nutrient deficiencies for the remaining season and show different scenarios based on different decision points. Ideally, we can offer an optimal strategy given farm-level inputs to optimize yield and/or fruit composition by grape market. Both decision tools can be hosted online, either on regional web servers or on the MyEV platform, with an easy-to-use interface, and generate reports for tracking results. During early 2024, a second industry survey will be administered to help address key goals and outcomes of the research. That survey will be tailored to understand changes in knowledge, practice, or acceptance/adoption of new technologies that are developed. This will also permit us to analyze barriers to technology adoption in the US grape sector. As we obtain more datasets, we will compile and analyze them together using econometrics to disentangle marginal effects of nutrients on fruit quantity (yield) and quality (multiple parameters) and to compare across vineyards and regions. A full meta-analysis report will be developed that includes a literature review, an econometric model that incorporates yield and nutrient data, and a discussion of results and implications going forward. We will also continue to engage with the other members of the project team to provide economic results for developing experiments related to the economic impact of nutrient management on vineyard production.

What was accomplished under these goals? This project is developing grower-friendly decision-aid tools for vineyard nutrient management to optimize inputs and business profitability via improved vineyard productivity and fruit and product quality, while minimizing adverse impacts on the environment. The tools--remote sensors that determine grapevine nutrient status coupled with modern plant tissue sampling protocols--will give growers near real-time in-field access to spatial and temporal metrics for vine nutrition variability. They will enable growers to act upon these measures via variable rate synthetic or organic fertilizer application. Impacts on crop yield and quality for all grape sectors--fresh, wine, juice, raisins--are measured. Long-term impacts of this project are 1) grape production will become more sustainable with lower environmental impact and more consistent annual production; 2) growers will optimize vineyard nutrient management by grape type and market; 3) fruit packers and processors will improve their market competitiveness; and 4) consumers will have a more consistent supply of healthy and affordable fresh grapes and grape-derived products. Following is a summary of research and accomplishments for each of the four project objectives. 1) Develop non-destructive tools to measure grapevine nutrient status: In California and New York, unmanned aerial system platforms were used to collect spectral imagery using multispectral and hyperspectral sensors in commercial vineyards at times coinciding with tissue sample collection (Objective 3). Procedures were developed to radiometrically correct the hyperspectral imagery, extract individual vine spectra from canopy classified pixels, build different nutrient models, and create nutrient prediction maps. Trials were also initiated with potted vines to measure leaf spectral signatures of vines varying in nitrogen (N) or magnesium (Mg) status in parallel with tissue samples. Remotely sensed datasets were created for the early 2021 growing season, and grid layers were created and georeferenced to Google satellite images. In Washington, a ground-based sensing platform was developed to estimate and map grapevine nutrient status over 3D canopy surfaces. The platform comprises hyperspectral, multispectral camera, and RGB-D cameras. Canopy images in three commercial vineyards with varying N or potassium (K) treatments were acquired in 2021 at times coinciding with tissue sample collection (Objective 3). Processing of color, depth, HSI and multi-spectral images collected is ongoing. 2) Determine the efficiency and suitability of precision vineyard nutrient management: Field plots were established with vine nutrient deficiencies. Tissue samples were collected at veraison in 2020 and bloomtime in 2021 for nutrient analysis. Also, tissue sampling strategies are being tested in NY (cool/humid) and WA (warm/dry) to validate and translate sensor data. In random-stratified sampling, select data layers are subject to k-means cluster analysis. Samples are then randomized within each of the identified clusters. In an alternative sampling protocol, Sentinel-1 and NDVI imagery are used to compare random and spatially directed sampling. Validation sampling protocols were established in five cooperating vineyards in NY and three in WA. Additional test vineyards and nutrient management activities were identified in NY and VA. MyEfficientVineyard (MyEV) was developed to upload, process, visualize, and download sensor data and vineyard maps ( Because satellite and drone imagery is raster data, methods were used to import raster data into MyEV and convert them into point data for comparison with other vineyard information. For variable-rate fertilizer applications, spatial prescription maps are being integrated with precision agriculture hardware/software for variable-rate application of dry or liquid fertilizers. Prototype configuration was developed to convert vineyard spray equipment for use with variable-rate liquid urea applications. 3) Define grapevine nutrient thresholds based on environment and production market: Seventeen replicated on-farm trials were established in five states. These trials will serve as test beds for sensor development and validation (Objective 1); to test precision vineyard nutrient management approaches (Objective 2); to develop enhanced tissue sampling protocols (Objective 3); and to provide data for socioeconomic analysis (Objective 4). In CA, field trials were established with table, raisin, and wine grapes; in WA, with wine and juice grapes; in OR, with wine grapes; in NY, with juice and wine grapes; and in VA, with European and hybrid wine grapes. Nitrogen supply is being manipulated in ten of the grower-cooperator trials, K is being manipulated at two sites and Mg at a single vineyard. In addition, five pot experiments were initiated in CA and WA to explore sensor responses to a wider range of nutrient supply (focusing on N, K, and Mg) in wine and table grapes. Tissue and/or soil samples were collected from the field sites during both 2020 and 2021. Macro- and micro-nutrients were analyzed in tissue samples from most of the field trials. Plant growth, yield, and fruit composition data will be collected from all field trials, and effects on wine quality will be evaluated in WA, OR, and VA. The 2020 baseline data from WA are the most complete, and indicated that blade nutrient concentrations were not well correlated with petiole nutrient concentrations. Depending on the variety, nutrient removal from the vineyard with the harvested fruit amounted to 2-3 lbs N, 0.6-0.7 lbs P, 5-7 lbs K, and 0.4-0.5 lbs Mg per ton of grapes. Thus far in the other field trials, early season leaf chlorophyll and shoot growth have not been altered by varying N, K or Mg supply treatments. 4) Estimate economic impact and feasibility of nutrient management decisions, extend knowledge to stakeholders, and advance understanding of grower decision making: An industry survey was developed and administered in spring of 2021; it was completed by 322 individuals, primarily grape growers (remainder were consultants and management companies), representing 176,000 acres or ~10% of the US vineyard acreage. The survey provided key information on how growers sample their vineyards and make nutrient management decisions. The top five most important nutrients they manage are N, K, B, Mg, and P. Many growers are working with crop consultants to devise nutrient management plans, and many are not currently using technology for nutrient management. Historical vineyard data were obtained from farms in OR and NY. Weather data were obtained from OSU's PRISM group in a 2.5-km grid across the US and were used to calculate nonlinear weather responses. We are soliciting more data from the project team and are contacting growers who are willing to share datasets as indicated in the industry survey. An initial meta-analysis of the OR vineyard data to examine relationships between yield and berry composition found the top three positive correlations were for berry K, titratable acidity, and total phenolics. A PCA found that the most influential variables include berry N and anthocyanins. These results provide a basis for the planned economic modeling strategy and will be helpful in assessing nutrient impacts on quality and economics. A logo and branded project name (HiRes Vineyard Nutrition) were developed for use in outreach activities. A project website ( was developed and includes information on the project team, news, events, and grower resources. Reports will be added to "Research Findings" as they are developed by the project. Three social media networks are being used, including Twitter, Instagram, and LinkedIn. Given the early nature of this work, relatively few presentations and no publications have occurred to date.


  • Type: Websites Status: Published Year Published: 2021 Citation: