The fertilization and irrigation programs for Open Hydroponics Systems begin their life each year with an “Orchard Information Master”.  It’s basically a collection of the information needed to determine how much fertilizer to apply, the ratio of the different components of the fertilizer, and the basic irrigation program.

Here’s this year’s Orchard Master web page for our Rock Bottom grove: http://www.arapahocitrus.com/files/rockbottom/master

You’ll see that there are a number of items on the download list.  The Orchard Information Master itself is the controlling document, and the other items are necessary to provide the details and general idea of the condition and size of the trees.  We gather and record all this information for each irrigation zone in a grove, then send it to Japie Kruger so he can build the programs.

If you download and open the Orchard Information Master file, you’ll see that it opens to the Metric tab.  To see the same information in pounds, gallons, boxes, acres, etc., just click on the next tab to the left down on the bottom.  When Japie builds the programs, he actually does it in metric units since it’s so much simpler — kilograms and liters are easier to work with than pounds and gallons when building formulas with percentages and ratios.  Not to worry, though — when the programs are finished, we just convert everything back into English units so that the grove managers can set up the Netafim NMC controllers to run the systems.

The Orchard Information Master is broken down by irrigation zones.  The flows, tree characteristics, and leaf, soil, and water analysis are all required to complete the form.  It takes a fair amount of work to pull it all together, but the nice thing is that you only have to do it once a year.

Perhaps the most important, yet most confusing, concept is the “% Canopy Coverage”.  All the programs are first built as if the trees were fully mature and grown to the point where they fill the space allotted to them.  For smaller trees, though, this would result in too much water and fertilizer.  So, the % Canopy Coverage is estimated, and the amounts of water and fertilizer are reduced by that percentage.  For example a block of trees with 70% canopy coverage would receive 70% of the water and fertilizer required for a full size tree.

The Orchard Information Master provides the pieces of the puzzle necessary to build the water and fertilization program for the year.  The program becomes the basic operating schedule for each day of a month.  Then, we fine-tune things as necessary based on the weather conditions and other factors.  You can’t skip steps — the everything has to move through the process the same way every year.

More on Orchard Information Masters in later blog posts.

Pete