See how nutrient use efficiency is changed for different nutrients by soil acidity.

Soil health is a complex issue that goes beyond the “big three” nutrients. Soil acidity is an important factor that affects nutrient use efficiency—a measure of how well plants use available nutrients—and it has a direct impact on soil fertility and plant growth. According to an article by the South Florida Beef Forage Program, “maintenance of adequate soil pH is essential for long-term persistence and productivity of grass pastures in Florida.” Explore the relationship between nutrient use efficiency and soil acidity.

Nutrient Use Efficiency and Soil Acidity

The article defines soil acidity as “a property that describes the relative acidity or alkalinity of the soil. The pH scale of soils ranges from 1 to 14. Lower the soil pH typically means greater the acidity.” Soils in Florida are mainly acidic, around 4 to 6. Warm-season forage grasses typically grown in Florida are generally more tolerant of soil acidity than legumes and cool-weather grasses.

Soil acidity affects plant growth in a number of ways, such as:

  • The toxicity of hydrogen ion (H+), aluminum, and manganese.
  • A deficiency of essential nutrients like phosphorus, magnesium, and micronutrients.

The standard lime-requirement test for Florida is the Adam-Evans test. Florida’s sandy soils have a lower buffering capacity than clay-based soils or soils with a high organic matter composition, so it takes less time to raise pH through liming. Materials used for liming include dolomitic and calcitic limestone, calcium and magnesium oxide, slag, sludge, and wood ashes.

A neutral pH is the optimal state for most nutrient uptake. The article explains the following relationships between soil acidity and nutrient use:

“Nitrogen – Soil pH influences soil microbial activities that affect nitrogen availability in soils.”

“Phosphorus, potassium, and sulfur – Availability of phosphorus, potassium, and sulfur generally increases in response to lime application.”

“Calcium and magnesium– Because lime materials often contain calcium and magnesium, the availability of these nutrients is increased.”

“Micronutrients- Although the availability of most micronutrients decrease as the soil pH increases (with exception of molybdenum, which appears to be less available under acidic pH), micronutrient deficiency in Florida pastures is rare.”

Soil testing is the best option for determining soil pH needs, and they should be performed every three years. Liming should take place at least 3 months prior to spring fertilization so the materials have enough time to react in the soil.

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.