Potassium for a Healthier Almond Crop
Maintain potassium at adequate levels to enhance productivity and prevent deficiencies that reduce almond yields.
Almonds love potassium (K). They require large amounts of it to remain vigorous and productive, even more so than nitrogen. Each almond orchard is a unique environment, and different soil types hold varying amounts of K and release it differently, which can make it tricky to manage K effectively.
“Growers who want to maximize yields need to stay on top of their K applications,” says David Doll, University of California Cooperative Extension nut pomology farm advisor for Merced County. “Otherwise, deficiencies will reduce return bloom and decrease spur longevity, which affects yields over time.”
Base Management Decisions on How Much K is Available to the Plant
Although most soils contain large amounts of potassium, relatively small amounts of it are in a form plants can use. Consequently, growers should base management decisions on how much potassium is available when the plants need it rather than on how much potassium is available in the soil.
Potassium uptake in almonds is linear, with as much as 70 to 80 percent of total uptake complete by mid-June. For almonds growing in soils with a low cation exchange capacity (capacity of the soil to hold on to essential nutrients), such as sandy soils and sandy loams, smaller applications made on a frequent basis ensure potassium levels remain at sufficient levels throughout the growing season. For heavier soils like clay, growers can stretch applications further apart.
Replenish K Lost at Harvest
University of California Davis (UCDavis) studies show that 76 to 80 pounds of potassium leave the orchard with every 1,000 kernels harvested. To sustain healthy crop production in the long term, growers must eventually replace any potassium that leaves the field at harvest time.
“Replacement of potassium that is lost at harvest is something growers should be working on throughout the year,” says Doll. “To accomplish this, more and more farmers are combining dormant-season banding practices with in-season applications.”
Prevent Deficiencies with Continued Monitoring
Deficiencies develop gradually over time and visual symptoms can take years before they show up. Plants lacking in potassium often show delayed or stunted growth. Other deficiency signs include inward curling of leaves, discolored leaf tips and marginal scorching. When severe, potassium deficiencies can increase the loss of fruiting wood, which results in reduced crop loads.
Continued monitoring and fertilization in the orchard helps growers build and maintain K at levels where deficiencies are less of a concern. Regular soil testing, taken a minimum of every three years, can help almond growers identify nutrient trends over time, additionally annual leaf samples help growers keep track of K levels.
“Mid-July leaf samples work well because tissue levels are relatively stable at that time of year,” says Doll. “Take two to three leaves from five non-fruiting spurs for at least 15 to 20 trees across the block. Trees should be 100 feet apart. To maintain sufficient levels across the orchard, UC Davis recommends shooting for a target potassium level of 1.6 to 1.8 percent.
Agro-Culture Liquid Fertilizer Potassium Products
Sure-K® is a clean, chloride-free potassium solution engineered for maximum plant uptake. It has a neutral pH, making it ideal for application with most crop protection products.
Kalibrate™ is an enhanced-efficiency potassium fertilizer formulated with the added benefit of 6% sulfur. While nitrogen, phosphorous and potassium are generally applied to crops in the greatest quantities, including the other nutrients like sulfur are keys to optimal plant growth.
In cases where it is customary to split seasonal fertilizer needs into a number of smaller applications, Kalibrate may be used for early-season potassium, while Sure-K may be more appropriate for mid- to late-season foliar applications.
While the objective with any fertilizer application is to apply plant available nutrition, many fertility products also contain elements that can have a negative impact on the soil and plant health. The lack of chorine and a near neutral pH found in the AgroLiquid’s family of products makes them a more sustainable option in plant nutrition.
For more information on AgroLiquid potassium products and the company’s full line of other great nutrient solutions for a variety of cropping situations, visit AgroLiquid.com.