Niederholzer warns soil fertility and nutrition is a specialized field

By TIM HEARDEN

Capital Press

WILLIAMS, Calif. -- Almond growers in a recent series of workshops were encouraged not to let up on their orchard management practices.

Experts from the University of California Cooperative Extension said almond and other trees need the right balance of water and nutrients to flourish, and they urged growers to keep testing their orchards for both.

Franz Niederholzer, a UC farm advisor in the middle Sacramento Valley, said almond orchard soil fertility and nutrition is a specialized field and that growers should seek a business relationship with a professional.

He said growers need to consider the environmental impacts of fertilizers while providing their trees with the more than a dozen essential mineral nutrients they need to survive and reproduce.

For instance, orchardists can conduct a leaf sample in July to determine whether the trees have enough potassium, then apply fertilizer if they don't, he said.

"Almond trees with potassium deficiency have a higher number of spurs die at the end of the growing season," Niederholzer told about 30 growers and students Nov. 28 at a banquet hall here. "This year's potassium deficiency is next year's crop loss."

Advisors delivered a similar message Nov. 27 in Woodland and Nov. 29 in Yuba City, as they gave an all-day course on the basics of almond production in the southern Sacramento Valley. The lectures proceeded through the life of an orchard, from how to choose the right rootstock to harvesting the crop.

The scientists said feeding the orchard with the right levels of water and nutrition is essential. With water, orchard managers need to consider when to irrigate and how much water to apply, said Rick Buchner, a UC farm advisor based in Red Bluff.

In general, farmers tend to look at wet soil surfaces and assume their orchards are getting enough water, which isn't always the case, advisors have said. Extension officials have encouraged growers to invest in such testing equipment as pressure bombs, which are sort of like blood pressure tests for trees.

Almond production requires an enormous amount of water -- about 9,000 gallons per acre per day in the summer, Buchner explained. While some deficit irrigation at certain times can be beneficial to nuts, full irrigation after harvest in dry years helps bud set and production in the following year, he said.

Online

UC-Davis Fruit and Nut Research and Information Center: http://fruitsandnuts.ucdavis.edu/

UC Drought Management: http://ucmanagedrought.ucdavis.edu/

UCCE Water/Irrigation Program: http://cetehama.ucanr.edu/Water___Irrigation_Program/

UC Statewide Integrated Pest Management Program: http://www.ipm.ucdavis.edu/