UC researcher Sebastian Saa reviews
the almond nutrient budget model
under development for growers
attending the recent Nickels Field Day.
The latest Almond Board–funded research led by Patrick Brown with the UC Davis Dept. of Plant Sciences offers an updated in-season nutrient budget model that will help growers make management decisions that hit the Four R’s — right rate, right source, right timing and right location. The model, which is being validated this season with a view toward release for the 2013 crop, aims to optimize production and minimize environmental impacts in nitrogen fertilizer management.
There are a number of key components to the budget model to help hit the four R’s. For rate, it is important to estimate crop load. In mature almond orchards, this is the key factor that drives nitrogen demand. Current research indicates from 55 to 70 pounds of N are removed with every 1,000 pounds of kernels harvested. For budgeting purposes, UC researchers recommend using 60 pounds of N. The model will also take into account nitrogen that is supplied by nitrates in the water.
Current best practices suggest 80% of the N should be applied between bloom and mid-June, and 20% applied as soon as possible after harvest to trees with healthy leaves.
This research also aims to develop protocols for leaf sampling and nutrient analyses in April, so that in-season adjustments can be made. Promising protocols are being validated this season and will be detailed soon.
More information and findings from this research can be found at the Almond Board website .