Lime Application Rates for Pecan Trees

Soil pH, a measure of the acidity or alkalinity of soil, determines that the capacity of a plant to take in sulfur, phosphorous, potassium and other nutrients. Adding lime to acidic soil makes it more alkaline. The recommended soil pH varies with the species of plant. Since land pH varies by climate and geography there’s not any normal application speed for all pecan trees. Pecans (Carya illinoensis) have been grown commercially in the warm, humid climate of the Southeastern United States but can be increased in U.S. Department of Agriculture plant hardiness zones 5 through 9.

Soil pH and Pecan Trees

Soil pH is measured on a scale of 1 to 14. Some less than 7 is acidic or “sour” soil; acidic soils are usually found in areas with heavy rainfall. Some over 7 is alkaline or “sweet” soil; alkaline soils are usually found in arid climates with little rainfall. Pecan trees grow best in a soil pH of 5.5 to 6.5. If the pH is below that, adding lime will raise the number. Most garden supply centres sell soil test kits that may measure soil pH adequately.

Lime Kind

Powdered calcium carbonate, commonly called dolomitic lime, is made by grinding stone and is usually utilized to adjust soil pH to get pecan trees. The fineness of dolomitic lime powder is measured from the magnitude of the mesh the particles may pass through. Higher mesh numbers indicate comparable particles of lime that dissolve in the soil more quickly; for example, 40- to 50-mesh particles will dissolve in the soil more quickly and raise pH more quickly than 8- to 20-mesh particles. Dolomitic lime is often sold in the shape of pellets made from finely ground stone. They are easier to propagate and therefore are less dusty, but they’re more expensive and slower to alter soil pH. Should you use pellets, you should till the soil a couple of days after you use the pellets when they’ve had a chance to soften. You can sometimes buy lime suspended in a combination of water and particles of clay. While this is not difficult to apply, it doesn’t work any quicker than lime in a dust form.

How to Insert Lime

The right time to apply lime to the soil for pecan trees is prior to planting them. Commercial growers applying lime to many acres of pecan trees receive their land tested to acquire precise rates of program. A home gardener planting a few trees can mix dolomitic lime powder completely into the top 6 to 8 inches of soil and test the soil until the pH is in the optimal range. Even though a pH of 5.5 to 6.5 is great for a pecan tree, even if your soil pH is naturally between 5 and 7, adding lime won’t likely improve the development of your tree.

Lowering Soil pH

If your soil pH is above the recommended range for pecan trees, you can lower it by adding elemental sulfur. Apply the sulfur into the planting bed into the thickness of the pecan tree’s root zone until the soil pH is between 5.5 and 6.5. When applying it into an existing tree, then remove the soil from around the roots, then add sulfur till you reach the perfect soil pH and return the soil around the tree.

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