As irrigation systems come back online in the spring, California tree crop growers have an important opportunity to fine-tune their fertility programs. In a recent Agronomic Minute, Dylan Rogers, Sales Account Manager for AgroLiquid, shared practical guidance on how spring fertigation can be managed more efficiently as trees move into active growth.
Rogers explained that once trees leaf out and irrigation begins, growers should focus on closely matching fertilizer applications with the tree’s nutrient demand curves—particularly for nitrogen and potassium. “Let’s try to stay as closely as we can to those demand curves,” he said. Rather than applying large amounts of fertilizer all at once, Rogers recommended smaller, more frequent applications to improve efficiency and reduce losses.
Applying a large “slug” of nitrogen followed by heavy irrigation can lead to leaching, especially in lighter soils. By breaking applications into smaller doses, growers can better protect nutrients and ensure they remain available to the tree during critical growth stages.
Nutrient uptake also shifts as trees transition from relying on stored reserves to actively pulling nutrients from the soil. Rogers noted that once photosynthesis ramps up after leaf-out, soil and tissue sampling become even more important. Monitoring those samples throughout the season allows growers to track trends and adjust fertility programs as needed.
Weather events are another key consideration during spring fertigation. If significant rainfall is forecast, Rogers advised adjusting fertilizer timing and rates. In some cases, skipping an application or splitting it before and after a rain event can help minimize nutrient loss. “We’ve got the ability to make those adjustments on the fly,” he said.
One of the advantages of liquid fertilizers is flexibility. Running nutrients through irrigation systems allows growers to create customized prescriptions, apply smaller weekly or even daily doses, and better align fertility with crop demand throughout the season.
For more information on spring fertigation strategies, visit AgroLiquid.com.