Introduction to the
CG Pro-I Calculators
Background to Analysis
Garden Tip
Technical Bulletin Series
Introduction to the Garden Calculator Pro I

Audio Overview (while reading)

Listen to an audio summary while reviewing the sections of this tip

Why is Matching Irrigation to Soil Important?
Water Waste must not be ignored! Drought in the Southwest US continues while aquifers and reservoirs are depleted. Landscape water accounts for approximately 50% of total residential water consumption. This amounts to about 7% of total water consumption. The California estimate of water use for irrigation was reported at approximately 500 billion gallons.
At present nearly 30% of this water is being lost to needless evaporation, and this is due to irrigation moisture being too shallow. An excessive amount of irrigation being done through spray or high-rate drip. Not slow-drip. Scheduling is too frequent and too shallow. The oft ignored 35 billion dollar unasked question is "How deep does each irrigation penetrate?"

We can't continue to waste 35 billion gallons of water each year!
Deep Irrigations reduce evaporation substantially.
Shallow and frequent Irrigations increase evaporation.

Applying the correct water volume at the correct flow rate
Is how-to assure optimum depth and minimum waste
Matching Irrigation to Soil is How to Accomplish this!

Occasionally we do get "rainy seasons."
This doesn't change how very precious our water resources are

GC Pro-I Calculators
This group of fully automated analysis calculators are designed to make matching soil and irrigation easy and straightforward. They contain hundreds of pages of background formulas, algorithms and report two pages of results while asking only a few questions. To best understand how much science is actually built into these calculators, the Soil Explorer is available to demonstrate this.

The Soil Explorer
This free to use software actually calculates the Hydraulic Conductivity of the soil in compliance with the USDA's published chart.

As you can see, within each soil type color group, the flow rate (at saturation) varies by 1,000%, this means within that same group moisture flow can vary as much as 10 times (faster or slower). To properly match irrigation application rates to the soil being irrigated, we need to get much closer than this. The algorithms in the Soil Explorer will be accurate to the USDA chart within 5%.

Compare the USDA flow rate chart above with the Basic Soil Composition Chart seen below. Simply knowing which soil type existing where irrigation is occurring, often leaves an enormous error as regards how the soil will respond to irrigation moisture movement.

If you'd like some background on just what factors are analyzed by these calculators and get a better understanding on how various soil types respond to water application, click here to use the Soil Explorer.

Using the Soil Explorer, you can become familiar with how adjusting the flow rate will affect the depth of moisture. The Explorer reports how fast water can be applied before reaching saturation, how fast a particular soil type can accept moisture, how much water is needed in order to produce field capacity in a particular soil. It uses the wilting point of that soil to calculate the amount of water that will be needed to achieve field capacity.

The formulas and algorithms in the Soil Explorer are also in each GC Pro-I Calculator, only they work in the background. The Explorer was developed to help appreciate the reliability in the GC Pro-I Calculators as well as provide insight on how soil moisture depth varies according to soil composition and applied irrigation flow rate (per square foot.)

Just Guessing about which type Emitters to Use?

Way too often irrigation systems are simply copied from other popular local systems. Unfortunately, many irrigation systems in the desert southwest utilize spray type, or rapid drip emitters. These fast flow devices put out too much water to allow for adequately deep moisture permeation of the soil. The result is poor distribution, high evaporation, and wasted water. This also creates shallow root systems causing stressed plants.

Using the Soil Explorer
Try using Dripperline flow of 0.75 gph
Then try plugging in a high flow rate
Shrubbler (6 gph / sq. ft.)

Note how moisture depth is substantially reduced!

More than wasted water!
Not only water waste, but plants are being stressed and dying because far too many irrigation systems are poorly designed and improperly scheduled.
Why? Soil composition is basically being ignored. With slow draining soil, even hand watering requires 20 to 40 minutes of slow application in order to penetrate deeply enough to support a strong root system. Who stands in one spot for that long?!

Fast draining soil too has many parameters that need to be addressed.

Plants look like this

When they should look like this

Thriving on good distribution
and adequate deep water

In regions where annual rainfall is not enough to support normal plant life, or areas impacted by seasonal drought, proper irrigation is vitally needed in order to sustain plant life and plant health for local landscapes and gardens.

There is a genuine science for proper irrigation. Soil composition, the make-up or mix of the soil particles, differs greatly between various soils in each neighborhood. If the irrigation system does not properly match the composition of the soil, either water will be wasted or the plant will stress and decline.

Gone is the era of "guesswork-irrigation" for drought prone regions. Water is a precious resource, and plant health is vital towards each human beings' sense of happiness. We need beautiful and healthy landscapes and gardens, just as we need to conserve water.

Because the science for dealing with this can be quite complex, the Garden Calculator Pro-I has been designed to make the method of accomplishing these objectives understandable, practical and quick.

This science is based on
matching the irrigation being applied
to a soil to its' composition.
Is applying the same rate and amount of water to a clayey soil
as to a sandy soil going to work?

The factors involved in determining this "Match" can seem complex and confusing. This is why the online Garden Calculator Pro-I has been designed and provided free without advertising.

A few simple questions answered; then the complex part of analysis is performed by Horticulturally Approved Algorithms. The subsequent recommendations are easy to understand and implement.

You will find plenty of educational links within each Calculator to help provide the background that is key for trusting and implementing recommendations provided within each analysis.

If you have not made use of the GC Pro-I yet,
CLICK HERE to visit.