Mon 9 Feb 2009
- It has an effect on the availability of nutrients
- it has an effect on soil micro organisims. Soil-borne bacteria needs a range between 5.4 to 8.0
- It has an effect on root cells which affect the root’s ability to absorb nutrients and water
- It has an effect on the solubility of toxic substances
the pH scale runs from 0 (extremly acid) to 14 (extremly alkaline). The middle of the scale 7 is the neutral point. the main thing about this scale that will confuse gardeners is the scaling of the values. You see each pH unit on the scale represents a ten fold increase or decrease in relative acidity or alkalinity. For example a soil with a pH of 5.0 is 10 times more acidic than one with a pH of 6.0. The power of ten carries acros multiple values to so a soil with a pH of 8.0 is 100 times more alkaline than one with a pH of 6.0.
- How to measure the pH of your soil
- what is the optimum pH for the plants you want to grow
- How to correct soil that is to acidic or alkaline
When testing your soil you can either send in your soil to a lab for testing or you can go with a commercial kit and test it your self at home.
If your pH test shows a 6.0 or below you have acidic soil. The most common cure is to add lime to the soil to alance it out. The best choice of lime materials is finely ground dolemite limestone. Dolemite limestone contains calcium carbonate which common limestone does not. This is important because soils that need lime are often deficient in calcium and magnesium.
There is no set formula for applying lime it really depends on soil texture and composition. Here are the general rule of thumb applications.
to increase pH by one unit for each 1000 sQ feet to be treated add.
35 pounds - very sandy soils
50 pounds - sandy soils
70 pounds - loam soil
80 pounds - loamy clays and clay
If your soil reads eight or above than you have alkaline soil. Powered sulfur or a pine needles or sawdust as a mulch will help correct it. The rate of application will depend on the type of soil and the original pH. Ask your local county extension agent for assistence in determininng the amount needed to correct the soil.