The pH level of your soil affects the growth of your lawn plants and the nutrients available to them as well as affecting the absorption of any nutrients by the roots of the plants. It’s important to determine the pH level of your soil prior to Spring fertilising to ensure that your lawn has the very best start to the growing season. The fertilising requirements of your lawn depends greatly on the pH levels and therefore the nutrient needs of the lawn plants.
Soil pH or reaction, measured in pH units, is an indication of the acidity or alkalinity of the soil. Measured on a scale of 0-14, a pH test will determine the amount of hydrogen ions; as the pH units decreases, the more acidic your soil becomes. As your soil progresses from 7 to 0, the more acidic it is becoming. From 7 – 14, the more alkaline the soil is.
pH levels over 7.5 causes manganese, iron, zinc, iron and boron ions to be less available in the soil and for the plants. pH levels under 6 causes the solubility of calcium, phosphorous acid and magnesium to fall. In temperatures over 26 degrees Celsius, such as we have in South East Queensland from Spring through Summer, if your soil has a pH level of 3-5 you will need to take action to correct this situation can encourage the development of fungal diseases.
To make sure that your soil and therefore your lawn are getting exactly what they need grab a pH soil kit and undertake the test prior to undertaking any type of Spring fertilsing. pH soil testing kits are readily available, fairly inexpensive, easy to use and fast to show results. Don’t have a test kit? An old trick to give you an indication of the levels present in your lawn – Take samples of the soil and add to ½ cup of vinegar – if bubbling occurs then your soil is alkaline. If nothing happens, take a new soil sample and add ½ cup of water, stir and then add ½ cup of baking soda – if bubbling occurs then your soil is acidic. While not providing a very accurate measure of the degree of acidity or alkalinity of your soil it is a quick option to ensure you are on the right path to providing for your lawn.
Once you have determined the pH level of the soil below your lawn you can then choose a fertiliser that will aid your lawn in achieving optimum health and growth. If your soil is acidic then an application of garden lime or dolomite will be very appreciated. For alkaline levels apply sulfur. More information on pH levels and fertilising can be found at Daleys Turf blogs.