Optimization of Water Use in Vineyards in the Okanagan Using Precision Irrigation FINAL REPORT 1 Acknowledgments Funding for this project was provided in part by the Governments of Canada and British Columbia through the Investment Agriculture Foundation of BC under Growing Forward 2, a federal-provincial-territorial initiative. The program is delivered by the BC Agriculture & Food Climate Action Initiative. A special thank you goes to Scott Smith at the Summerland Research and Development Centre for his help and guidance. Disclaimer Opinions expressed in this document are those of the author and not necessarily those of the Governments of Canada and British Columbia. The Governments of Canada and British Columbia, and their directors, agents, employees, or contractors will not be liable for any claims, damages, or losses of any kind whatsoever arising out of the use of, or reliance upon, this information. 2 INTRODUCTION ....................................................................................................................................................................................................................................... 4 Three main objectives: ........................................................................................................................................................................................................................ 5 METHODOLOGY ...................................................................................................................................................................................................................................... 5 RESULTS ................................................................................................................................................................................................................................................... 8 Soil texture and moisture retention curves ........................................................................................................................................................................................ 8 Modification of all 5 irrigations system and first results ................................................................................................................................................................... 15 CONCLUSIONS ....................................................................................................................................................................................................................................... 20 APPENDICES .......................................................................................................................................................................................................................................... 21 3 ABSTRACT With the increasing demand on water resources in the Okanagan Valley, Le Vieux Pin and Lastella Wineries began a project to study and improve their irrigation techniques. The wineries are interested in reducing their water consumption by improving water application and delivery to match the physiological requirements of the vines and soil composition on a fine scale. Using NDVI (Normalized Difference Vegetation Index) and electroconductivity, in conjunction with GIS mapping, 29 pits were excavated throughout the vineyards and 76 distinct soil samples were analysed. Using this data, the irrigation system was adapted on a vine by vine basis. The final goal is to improve vine health, control plant vigor and thereby improve grape quality. A reduction of labour costs through automation of the system and the resulting reduction in time required to manage the canopy of the vineyards was a secondary benefit that will allow the vineyards to offset the cost of changing the irrigation systems over time. It is expected that the precision irrigation system with also reduce water usage within a few years time, once the vines have adapted to the new system. This report outlines project activities and preliminary findings from the project inception to February 2018. INTRODUCTION The changing climate in the South Okanagan, combined with the potential for issues around long term water supply has motivated Enotecca Wineries and Resort to obtain more precise information about their soils (structure, water retention capacity, macro and micro element composition) in order to better manage the irrigation system and fertilization. The project will be accomplished through 4 components: 1. Detailed analysis of both physical and nutrient properties of the soil and mapping these differences across the vineyards. 2. Installation of irrigation equipment for precise and timed delivery of water and nutrients specific to the mapped soil conditions. 3. Monitoring of total volume of water used for irrigation in the vineyard, along with evaluating the quality and quantity of production. 4. Dissemination of the project results through producer visits to the vineyard and through the wine and grape industry via workshops and presentations. 4 Three main objectives: The Okanagan valley is the only desert in Canada and is therefore characterized by high temperatures in the summer, low precipitation, and, due to the geological history, the soils contain a lot of sand requiring irrigation of vineyards to produce quality grapes. Enotecca Wineries and Resorts owns and operates Le Vieux Pin and LaStella wineries and 50 acres of prime vineyards, all located in the southern Okanagan. The three main objectives of this project were to: 1) Reduce the amount of water use in the vineyards by enhancing the application and the delivery of irrigation water and by controlling the amount delivered according to the soil/plant requirements in order to adapt better to the climate change. Also, to prepare for the possibility of water shortages and lack of available water for irrigation during droughts by having an irrigation system designed with precision, which can maintain grape quality with far less water. 2) Increase the knowledge within the project leads’ company and also within the grape growing industry in the Okanagan. The more that is known about the soils, the plants’ needs and how to improve the overall balance of the plant, the more business productivity can be improved. At the industry level, it is expected that this project will increase growers’ awareness around the need to manage the available water with precision and adapt to climate change as an industry. 3) Improve water management by understanding how the soil works and by modifying practices. This implies both: • Better time management of labour crew on a yearly basis • Increased health of each plant in the vineyard by managing the vigor and therefore enhancing the quality of the grapes: Improving the microclimate surrounding the grapes (less use of anti fungicide and insecticide) will also have a financial impact by saving on labour costs, spraying product costs; and will improve the quality of the grapes resulting in better wines. • The ultimate goal is to be able to sustain an outstanding grape quality. A good wine is not made in the cellar; it is made in the vineyard. As two boutiques wineries that strive to put BC on the world map as wine producing region, having uniformed vineyards and balanced grapes in terms of flavor and also chemistry, is the number one priority. METHODOLOGY 1) Electroconductivity and NDVI measurements In July 2015, soil electroconductivity and canopy NDVI measurements were taken by the Chilean company AGRO PRECISION. Using GIS technology, maps were generated and compared to identify 29 distinct areas throughout 5 vineyards. See two examples of the Electroconductivity maps below: 5 Map#1-Electroconductivity at Selona Vineyard and location of the 5 soil pits. Location of two of the pits for Selona 6 Map#2-Electroconductivity at Lastella Vineyard and location of the 5 soil pits. 2) Soil sampling These sites were then excavated, measurements of the different strata were recorded and a total of 76 soil samples were collected. These samples were analyzed in Victoria at the BC Ministry of Environment with help from the Summerland Research and Development Centre in Summerland, BC. See Appendix #1 and Appendix #2 for detailed results. 7 RESULTS SoiL texture and moisture retention curves Scott Smith from the Summerland Research and Development Centre, Summerland, BC helped to draw some conclusions regarding the vineyard’s soils according to the soil analysis. Irrigation management requires an understanding of the water-holding capacity of a soil (particularly in the root zone of the grapevines); of the water-intake rate of the soil; of the root system of the types of vines to be grown; and of the amount of water that the vines require. There are four important levels of soil moisture content that reflect the availability of water in the soil. They are commonly referred to as: saturation, field capacity, permanent wilting point, and plant available water. • Saturation: Saturation is the point the soil pores are filled with water. Saturation usually occurs for short periods of time, either during heavy rainfall events or when soil is being irrigated. • Filed Capacity: Field capacity defines the amount of water remaining in the soil after downward gravitational drainage has stopped. This value represents the maximum amount of water that the soil can hold against gravity following saturation by rain or irrigation. • Permanent Wilting Point: The amount of water a soil contains after