The pH of the soil is a significant factor in determining whether or not your plants will grow and flourish. Iron chlorosis and other plant nutritional deficits are symptoms of alkaline soil, which is soil with a pH higher than 7.0. This is because alkaline soil prohibits plant roots from adequately absorbing nutrients. Conducting a soil test to verify that the issue is with the pH of the soil is the first step to taking any remedial action for alkaline soil. This will disclose the pH of the soil as well as the quantities of nutrients in the soil.
What Causes Alkaline Soil?
The factors that are creating the high pH levels in your garden might influence which treatment for alkaline soil is the most effective. According to the University of Delaware, the optimal pH range for plant growth is between 6.0 to 7.0, however if your soil’s pH levels are higher, you may need to amend the soil in order to ensure healthy plant growth. It is likely that you overcorrected the acidity of your soil by applying an excessive amount of lime if it was previously acidic. Additionally, ensure that the water being used for irrigation is not alkaline, since this might have an effect on the pH of the soil.
According to Water Conservation for Lawn and Landscape, the soil in some regions of the United States, particularly in the states located in the Western region, is dry and contains a great deal of carbonates, both of which may elevate the pH of the soil to 8.0. It could be challenging to bring the pH of these soils down since the soil itself has a high starting point.
According to the University of California Agriculture and Natural Resources, a soil may be considered sodic if it has a pH of 8.5 or above. These soils contain relatively low amounts of salt but relatively high quantities of sodium that can be exchanged. Because of its weak structure, this form of alkaline soil calls for a treatment method that is distinct from those used on other types of alkaline soil.
Correcting Alkaline Soil
It is far more difficult to correct alkaline soils than it is to fix acidic soils, particularly if the soil includes components that naturally raise the pH of the soil. Fertilizers that just contain phosphorous should be avoided, but applying fertiliser designed for alkaline soil, such as ammonium sulphate, may help raise the pH of the soil and the amount of nutrients it contains.
Applying elemental sulphur or sulfuric acid to the soil in the quantity that is recommended by your soil test will bring the pH of the soil down. According to the University of Delaware, if you add sulphur to soil in which plants are already growing, you should be careful not to add more than 8 pounds of sulphur per 1,000 square feet of soil, since doing so may cause damage to your plants. Add a substantial quantity of organic material to the soil. Peat moss has the potential to be acidic and is a fantastic alternative; however, if you are working with a limited budget, this may not be an option for you.
If you have naturally alkaline soil, it may be hard to bring the pH of the soil down to an acceptable level permanently. Altering the pH of the soil annually with alkaline-loving plants is another option. According to the University of Florida IFAS Extension, certain plants, such as English dogwood (Cornus foemina, USDA zones 6 to 10) and shasta daisy (Leucanthemum x superbum, USDA zones 4 to 9), may thrive in soil with pH values as high as 8.0.
Correcting Sodic Soil
After determining that the issue is caused by acidic soil, the excessive sodium content in the soil must be replaced with calcium. According to the University of California Agriculture and Natural Resources, this may be accomplished by adding gypsum, which is also known as calcium sulphate, to the soil. Amending the soil with elemental sulphur or sulfuric acid is recommended if it already has a high percentage of calcium carbonate. It is necessary to incorporate the sulphur into the upper layers of the soil, where it will enable the calcium carbonate to function as a suitable substitute for sodium.
This is not a quick process, and it might take many years before the soil has been completely corrected to the level of depth that is necessary for plants to grow. Gypsum or sulphur should be applied annually in the appropriate amount. A test of your soil will reveal the quantity of amendments that are required to restore the health of your soil.
If you want to enhance the structure of the soil, you should think about adding compost and other organic material. Maintain a regular testing regimen to determine the pH and sodicity of your soil.