Essential elements and soil properties: Reference guide

Elements, micronutrients, macronutrients, CEC, ENR, pH, organic matter . . . there are many terms and acronyms used in your soil report. What do they all mean? Here is your cheat sheet for how it all works together to help your plants thrive! Click the links to learn more about each topic, and scroll down to the bottom of the article for a downloadable PDF version of our Definition Sheet.

The elements on your soil report fall into different categories based on the quantities needed by plants.

MACRONUTRIENTS: 2 groups of Macronutrients (Primary and Secondary)

• Primary macronutrients: Plants use these in large amounts for growth and survival.
  
  • Phosphorus (P): Cell formation, root health, encourages bloom, transforms solar energy into chemical energy
  • Potassium (K): Root health, water regulation, photosynthesis, reduction of diseases, increases size and quality of fruits
• Secondary macronutrients: Needed in moderate amounts.
  • Calcium (Ca): Essential part of plant cell wall structure, strength in plant, used in root system and leaf development
  • Magnesium (Mg): Activates many plant enzymes needed for growth, central atom of the chlorophyll molecule, which makes it absolutely necessary to photosynthesis

MICRONUTRIENTS: Micronutrients are elements that are still essential for plant growth although they are needed only in very small (micro) quantities.

• Boron (B): Aids in production of sugar and carbohydrates, essential for germination of pollen grains and pollen tubes
• Copper (Cu): Important for reproductive growth, catalyst for other plant reactions
• Iron (Fe): Essential for formation of chlorophyll, carries oxygen, critical to photosynthesis
• Manganese (Mn): Involved in breakdown of carbohydrates and nitrogen metabolism
• Zinc (Zn): Essential for transformation of carbohydrates, regulates consumption of sugars

BASE SATURATION: Base saturation is the percentage of the total CEC (see below) occupied by basic cations including potassium, magnesium, calcium, and sodium.

ORGANIC MATTER: According to the USDA, “Soil organic matter (SOM) is the organic component of soil consisting of three primary components: small (fresh) plant residues with small living soil organisms, decomposing (active) organic matter, and stable organic matter (humus).” A healthy range is 2-6%. Learn more about organic matter here.

ENR (Estimated Nitrogen Release): ENR is a calculated estimation of how much nitrogen may be released from soil organic matter (SOM) in one year. 

CEC (CATION EXCHANGE CAPACITY): CEC is an indication of the soil’s ability to hold or absorb cations, including many nutrient cations applied as fertilizer. The higher the CEC, the more nutrients the soil can hold.

pH: Given on a scale of 0 to 14, pH measures the acidity or alkalinity in the soil. The industry standard for neutral is 7, but the best pH for your soil can vary based on the plants you're growing. Lime and sulfur are soil amendments used to raise and lower pH respectively.

BUFFER pH: The buffer pH indicates an acidic soil’s ability to resist a pH change. The higher the buffer pH reading, the smaller amount of lime is required to raise the soil pH.