Feb 17, 2021Mitigate almond tree stress with a science-based irrigation schedule
“We can’t control the weather, but thankfully there is an increasing number of tools at growers’ disposal to make strategic irrigation decisions and mitigate risks associated with certain conditions, not just weather, but also soil conditions,” said Matt Comrey, technical nutrition agronomist, Wilbur-Ellis Agribusiness.
When making irrigation decisions this year, Wilbur-Ellis Agribusiness’s Comrey encourages growers to use a science-based approach to maximize almond yields. He says that there are essentially three approaches to water management, and that growers should use at least two of the following to design an irrigation schedule:
- Soil-based approach
If there is less water in the soil, and the water is held at a greater tension, it will be more difficult for the almond trees’ roots to take up that water – resulting in tree stress. By using soil monitoring tools, growers can track soil moisture status and adjust water application rates and timing accordingly.
- Plant-based approach
Plants respond in different ways to keep their water supply and demand in balance, and most plant-based methods for irrigation management are based on the measurement of one or more of these responses.
The pressure chamber method, for measuring the tension of water within the plant, has been shown to be a reliable measure of water stress in almond orchards. “The one con of using a pressure chamber is that the tool doesn’t distinguish between types of stress,” added Comrey. “If you are utilizing a pressure chamber in a particularly weak or diseased portion of the orchard, it will not decipher between stress due to poor water supply and stress from disease.”
- Climate-based approach
This approach requires a deeper understanding and balancing of your irrigation application rates and plant evapotranspiration, or ET. This is the combination of transpiration, or water evaporation from plant leaves, and evaporation from the soil surface.
“I encourage growers to utilize at least two of these approaches because in the real world, the data or the feedback you get from each approach doesn’t always line up perfectly. There’s always some subjectivity,” said Comrey. “Carefully evaluating the information provided by multiple sources and consulting with local agronomic experts can help you determine the best irrigation schedule for your almond orchard this year.”