Soil is just dirt to many people, it ain’t much of anything, but to anyone that grows food or plants, soil is everything! When I think of all the soil tests our office sends off, the one question I get asked the most when the results are back is, “how much lime needs to be put out?” What we look at to determine the lime amount is the pH level. This post is all about understanding pH and why it matters.
To start with soil itself is made up of several components. Minerals, air, water, dead organic matter, and living organisms all combine to make up what is in our soil. How much water and air contained in the soil depends on the texture of the soil. Soil has three differently sized particles that it is composed of: clay, sand, and slit. The different ratios of each is what makes up the soils texture. You may hear people use the term “loam” when discussing soils. That term is used generally when the soils texture is ideal. Around these parts we have a sandier texture to our soil. Sandier soils cannot hold water very long and also lose nutrients faster than other textures. Along with the sandier characteristic of our soil, we also are prone to having highly acidic soils. In other words, our soils are typically going to be lower on the pH range than other places. That being said do not let a 5 and a 6 on the scale make you think there is not much difference. A 5 pH is 10x’s more acidic than a 6pH, and 100x’s more acidic than a 7pH. If that is confusing, do not worry it confused me too for a while. When I was younger the concept of low pH and high acidity confused me. It took me learning chemistry to really understand it. I will not bore y’all with the science side of it, but if you are interested in learning more on that you can visit a publication Mrs. Becky Griffin did where she explained that in a little more detail. (https://ugaurbanag.com/soil-ph-101/) Our main focus is understanding what that number means, how it effects the plants we grow, and how do we fix it.
With the lower the number the higher the acidity in in mind, let’s talk about what that can do to your plants. Speaking for most vegetables and lawns, you want a pH of around 5 to 6.5 depending on what is being grown. The higher or lower you go with this number starts changing the balance of nutrients your plants can absorb. If your pH is 5 or below, that nitrogen fertilizer may not get absorbed enough into the plant for it to actually work. That means not having the pH corrected could mean more money spent to fix the issues and less productivity out of the plant. On top of nutrients it needs not getting absorbed having too high of a pH or too low can also mean an excessive of nutrients that are not beneficial for plants. Lower pH can have elements like aluminum become excessively available, which can burn the plants roots. If your pH is too high your plants may develop yellowing between the veins of the leaves.
Each plant has different needs and understanding those first is crucial in making sure your soil satisfies those. Blueberries for example like more of an acidic soil, so having a higher pH is not good for them to grow correctly. So how exactly do we correct our soils pH? If your pH is too low, you would add the recommended lime to correct that issue. Agriculture Lime (called many different names: garden lime, aglime, lime) is ground limestone, specifically calcium carbonate. It not only helps with pH issues but also helps boost the calcium content of your soil as well. There is also dolomitic lime as an option. It is made from dolomite, which is a rock similar to limestone, except this particular rock also contains magnesium. Dolomitic lime is recommended when there is a significantly low amount of magnesium inside the soil. You can find lime in a few varieties, and depending on which you choose you will need the right kind of spreader to apply it. Lime takes a longer time to actually see results. Generally, around here you usually can see an improvement within three months. That is not always the case though. If your pH is too high, you can apply sulfur or aluminum sulfate to lower it. The only true way to find out what your plant or crop needs and what is in your soil already, is to get a soil sample done.
Soil is so much more than just dirt. Good soil and the right soil pH is crucial to having a healthy plant or crop. I hope this helped shed some light on how important it is to truly understand the dirt you are planting something in!
If you have any questions, suggestions, or want further information, please give me a call at or stop by the Effingham County Extension Office, (912)754-8040, 501 N. Richland Avenue, Rincon GA, 31326.
Joke of the Day: What is the most groundbreaking invention in history?? The Shovel!