The term pH is simply chemical lingo that describes how acid or alkaline a substance is. Checking the pH of a solid like soil isn't possible because the meters and sensors used to give this reading requires a free ion moving about in a fluid like water. In practice, soil pH is measureed by checking the water that's been exposed to the test soil.

 

The procedure for testing soil is very simple. Taking equal weights of soil and deionized water the the two are vigourosly mixed together for a few minutes. The sediment is allowed to settle and the water itself tested OR a probe can be inserted into the mud and the pH checked directly. The pH scale is numbered from 0 to 14; 0 being extremely acidic (like pure pool acid - Muriatic or Hydrochloric Acid) and 14 being extremely basic, alkaline, or "caustic" (Like Drano or any other liquid drain cleaner)

 

The most ideal pH range for soil is between 6.3 and 6.8 where soil bacteria prefer to live and thrive. At this pH range Nitrogen, Potassium, Phosphorus, and Sulfur are ideally usable for plants to absorb and utilize. These nutrients are the most needed and useful by all plants. Most plants prefer this pH rangeand whan the soil pH strays from this range then plants become susceptible to many kinds of diseases and have a hard time recuperating once foraged upon by your flock.

 

As soil becomes too acidic for plants (around pH 5.0 - 5.5) the key nutrients they need are more tightly locked up in the soil chemistry, decompose, or simply evaporate while other elements such as Iron, Copper, and Zinc become more soluble (dissolve) to the point of being toxic for many plants. An overabundance of these elements can inhibit proper plant growth or simply kill it if it's overly sensitive. You may notice excessive yellowing or thin stems due to the toxic effects.

 

Causes for acidic soil are generally boggy conditions in which leaves and other plant matter are decomposing and contributing a great deal of acids such as tannic acid (usually seen as brown water colored like peat) and carbonic acid. Carbonic acid is simply dissolved carbon dioxide in water -- like tonic water or carbonated spring water you may drink. Pollution and high amounts of rain can also contribute to low soil pH.

 

If the soil pH is too high (Basic or Alkaline) then this can create an overabundance of sulfur, molybdenum, or unusable forms of phosphorus. This pH condition might be seen in soil that sits atop a limestone deposit or receives runoff from such an area. High pH also causes necessary trace elements to be locked up in the soil matrix and the plant may show signs of nutrient deficiency.

   

Sulfur, iron sulfate or aluminum sulfate, Urea, urea phosphate, ammonium nitrate, ammonium phosphates, ammonium sulfate and monopotassium phosphate all lower the soil pH.

Applications of lime (Calcium Carbonate) or chalk, mason's lime, quicklime, slaked lime, calcium nitrate, magnesium nitrate, potassium nitrate, and sodium nitrate all can increase/raise the soil pH.

 

If you'd like to test soil pH yourself then there are test meters and kits available on the internet and at better nurseries. I'm a little leery of many of these since pH is a delicate thing to measure accurately within a tenth of a unit. It would be wise to consult a good local nursery or send a test sample into an environmental laboratory (Should be about $10-15 and they'll require a reason for the test -- liability issues)

 

I spotted a rather inexpensive meter, although I make no formal recommendation of this product. Many horticultural enthusiasts seem to like this simple meter and it costs just a slightly more than what you might pay for a test at a reputable environmental or soil lab.

 

 

Two models are available:

 

 

Model 1840 (seen on right)

 

Instrument instructions and other useful information are available by clicking on the picture       >>>>