California’s population growth, frequent drought conditions, and greater awareness of environmental water requirements have increased pressure on agriculture to use water more efficiently. A common irrigation practice for California fruit crops is to apply a fixed quantity of water weekly regardless of crop needs. This method frequently results in overirrigation and is often detrimental to fruit quality or yield.
This study sought to analyze the impact of traditional irrigation practices versus plant-aware irrigation by quantifying water and energy savings and comparing them to the quantity and quality of the grape harvest. The concept behind plant-aware irrigation is to adapt the duration and frequency of irrigation events based on plant water needs using sensors installed on the plant itself. In this approach, the entire plant in effect becomes an instrument that integrates the complex effects of soil moisture, climate, and leaf area variations. As the season unfolds — fruit ripens and mass and sugar accumulate — the plant can communicate the level of water it needs.
This project evaluated the technology and its application at three test sites in the wine country of Northern California. For each test site, Plant Aware Irrigation, developed by Fruition Sciences, monitored plant water needs in real time. The researchers set irrigation thresholds to trigger alerts for irrigation according to monitored variations in plant water indices and stages of plant and leaf development. Because water use drives photosynthetic activity, the research team set the irrigation threshold values at a level that would maintain sufficient photosynthetic activity for mature fruit production. The team also applied an analytical platform capable of characterizing climatic demand to convert sap flow data into actionable information for irrigation.
Calculated water and energy savings comparing control and plant-aware irrigation treatment areas on a per-acre basis over one full season achieved, conservatively, 325,354 gallons per acre and 192.7 kilowatts per acre. Across all tested vineyard locations, this amounted to 61 percent average water and energy savings. Vineyard staff indicated that the value of the project was in water, energy, and cost-savings potential through efficient pumping and selective watering. Vineyard staff members were encouraged by the promising vine-health improvements and the ability of the vineyards to provide quality wine.
Author(s)
Sudeshna Pabi, Marek Samotyj, Ryan Berg, Thibaut Scholasch, Marc Esser, Bo White
