Managing Soil pH to Boost Yields

Soil pH is the first thing to look at when you receive soil test results. A healthy soil pH can help optimize fertilizer use efficiency and crop yield, increasing your ROI.

Soil test laboratories measure soil pH and buffer pH. Soil pH is a measure of soil acidity and characterizes the soil as acidic (0-7), neutral (7), or alkaline (7-14). The buffer pH assesses the ability of the soil to change pH and can be used to determine how much lime is needed to change the pH to the desired level. Adding lime will reduce acidity, increasing soil pH.

Soil pH affects many different processes and most notably, affects nutrient and micronutrient availability. When soil pH drops below 5, farmers will start seeing major crop yield losses. At low pH levels, metals found naturally in soil – like manganese and aluminum – become more available and can become toxic to crops.

While different nutrients are optimally available at different pH levels, research suggests that the optimal soil pH range is between 5 and 7. Low or acidic pH is also harmful to microorganisms in the soil. At a pH of around 4, microorganisms slow down decomposition which in turn limits release of nitrogen and other nutrients to the soil.

A pH management strategy will help improve efficiency of applied fertilizers for better yield and ROI. Farmers can prevent low soil pH by implementing a routine soil testing program and monitoring results carefully. They can also work to increase nitrogen use efficiency through practices including split application, variable rate application, and carefully planning crop rotations.

For more information on managing your soil pH, listen to The Dirt podKast’s episode on The Importance of Soil pH. Once you’ve tested your soil, your local Smart Nutrition MAP+MST rep can help determine optimal application rates and timing.

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