pH – ACID, NEUTRAL AND ALKALINE
Your soils’ pH is an important factor, but one that is often overlooked in the eagerness to get your lawn down. pH is measured on a scale from 0 -14 with the lower numbers representing acid soils, the higher numbers alkaline soils and 7 being neutral.
The ideal pH range for your lawn is somewhere between 6 – 7.5. Basically pH affects the solubility of minerals and nutrients essential for plant growth, and if your soil is out of the optimum range nutrients become almost impossible to absorb.
Measuring a soil’s pH is easy to do and doesn’t involve a complicated scientific experiment, all you need is a pH testing kit. These are available at hardware stores and nurseries, or online at www.lawnstore.com.au and should last for many years. When doing the test, collect a few soil samples from different locations in your lawn site and mix these together to get an average reading of the whole area rather than just one location that may differ from the rest of the soil and give a false reading. Then, simply follow the directions in the testing kit and await the result before taking any further action if required.
RAISING pH WITH LIME
If your soil pH is acidic with a pH of less than 6.0, then you need to raise it to get it into the optimum range. Cultivating your soil with AGRICULTURAL LIME (calcium carbonate), which is finely ground limestone, will raise the pH and help neutralise acidic soils. How much lime you apply depends on the acidity of your soil and the pH increase required; the neutralising value of the lime and your soil type. Sandy soils are easier to adjust than clay soils. The finer the lime particles are, the faster they will act.
Always check the application rates on the bag. It could be anywhere from 100g/m2 – 250g/m2. Once you have spread the lime cultivate it into the soil either by hand with a mattock, (hard yakka), or with a rotary hoe for best results. Lime will also improve the structure of clay soils and drainage.
LOWERING pH WITH SULPHUR
To lower the pH of an alkaline soil cultivate with a sulphur product according to the application rates on the instructions.