Potential Hydrogen (pH) is the measurement of acidity or alkalinity in a solution and greatly affects chemical reactions

The pH scale is 0 (acid) to 14 (alkaline) - 7.0 is neutral

When the soil pH is extremely high (alkaline), some of the micronutrients precipitate out of the soil and become unavailable to the plant

When the soil pH is extremely low (acidic), some of the micronutrients become extremely soluble and may injure the plant

Note: Adjusting pH (after nutrients are added) is recommended as nutrients change pH