What is Soil pH?

Soil pH is a critical aspect of soil that must be understood and managed correctly if you want to be able to create and manage a successful sustainable life.  What pH your soil is determines a lot about what you can grow and where you can grow it as soil pH can very from plot to plot. 

http://bouman.chem.georgetown.edu/S02/lect14/ph.gif

What is soil pH?  

The easiest way I could think of to define pH is as follows,

p-means power as in 2 to the 10th power = 1024

H- stands for Hydrogen

So pH together stands for the power of Hydrogen ie. how many Hydrogen ions are present in the material you are measuring.

The higher the amount of Hydrogen ions that are present, the lower the pH will be.  This means that when you have a lot of Hydrogen present, the soil will be more acidic. The less hydrogen ions you have the more basic/alkalie the material will be.

The pH scale is what is called a negative logarithmic scale so it increases from 0 which is the most acidic and has the most Hydrogen ions present to the most alkaline or basic at 14.  Each step from 0-1 all the way from 13-14 is higher that the previous number by a factor of ten.

For example the most acidic thing on the pH scale would have a pH of 1 while the most alkali or basic material would have a pH of 100,000,000,000,000 if expressed as full numbers rather than on
the scale.
   

Soil pH and a Sustainable Life

What I want to really get into now is how knowing about pH is part of building a sustainable lifestyle.  The primary way that pH affects you when you are trying to build a sustainable life is how it affects your ability to grow food.  Certain crops and plants work better with certain levels of pH.  For example strawberries a common garden favorite like a pH between 5.5-6.5.  While other favorites like spinach and asparagus like a soil between 6.5-7.5.  So they they wouldn't make the best garden bed fellows.  The pH of your soil is a critical factor in telling you what can be successfully grown at your location.  Now you may still be able to grow things that are outside their preferred pH range but your success could be questionable.  


Planning your garden spaces out according to pH will save a lot of headache and expense in the long run.  If you have to continually put additives into the soil like lime to counteract acidity then perhaps you need to relocate the garden or grow something else there. 

Measuring soil pH is a really easy and cheap thing to do with today's technology.  You can either do it with a meter like this one or with disposable litmus strips.  A meter like this will give you a more accurate and precise readings than the litmus and they also last quite a long time if taken care of properly.  A meter like this will be useful if you have a large amount of ground to test or if you are consistently making adjustments to your soils pH.  
 
If you want you can also use litmus papers which when soaked in a solution of soil and water change color to indicate a general level of pH.  They are cheaper than the meter but they are one time use only and you will have to replace them once you run out of papers.