Potassium and phosphorus can become tied up in organic matter, minerals, and clay particles. Supporting beneficial soil microbes with products like BIOACTIVE LiquiLife+ can help cycle these nutrients into plant-available forms, improving nutrient efficiency and helping you get more from the fertility already in your soil.

Did you know that your soil likely contains more potassium and phosphorus than your soil tests are telling you? Soil tests measure the amount of plant-available nutrients in your soil, not the amount of total nutrients, and it’s the total nutrients number that tells you the true nutritional potential in your fields.

With the help of your soil’s microbial community, you can unlock the potassium and phosphorus that are tied up in the soil. Beneficial microbes release more nutrients for your plants without spending a dime more on fertilizer.

Potassium and phosphorus become unavailable to plant roots when they bind to minerals, clay particles, organic matter, and other compounds in the soil. Simply adding more through fertilizer applications isn’t always the answer. Through nutrient cycling, breaking down organic matter, and interacting with minerals in the soil, your soil’s biological community plays an important role in converting nutrients into forms plants can access.

Microbes and the Availability of Potassium and Phosphorus

Potassium is commonly held within soil minerals and clay particles. Microbes support the mineral exchange processes that cycle potassium between organic matter, minerals, and soil solution, moving it toward plant-available forms. The ten-dollar words for these processes are desorption and adsorption.

Phosphorus can be tied up with the calcium, iron, aluminum, silicate minerals, and carbon in your soil. Phosphate-solubilizing microorganisms (PSMs) interact with phosphorus compounds in the soil, moving phosphorus from unavailable forms toward forms plants can access.

Organic and Inorganic Forms Require Different Biological Processes

Where potassium and phosphorus are stored in your soil makes a difference in the way microbes convert them into plant-available forms.

Organic Potassium and Phosphorus

Organic matter is a primary food source for soil microbes. As they consume and decompose organic matter, they break down carbon compounds, freeing up the potassium and phosphorus that had been bound to the carbon. Then, they cycle these nutrients through the soil where plant roots can access them.

Inorganic Potassium and Phosphorus

When potassium and phosphorus are tied up in soil minerals and clay particles, microbes drive a three-step process to make them accessible to plants. While we could get into the chemistry weeds here, let us summarize by simply saying the microbes break existing soil minerals molecules apart, bind them into new forms, and use water in the soil to move nutrients in their new forms to plant roots. The ten-dollar words for these processes are disassociation, reassociation, and mineral exchange.

To Improve Potassium and Phosphorus Uptake, Take Care of Your Microbes

You may have noticed that we haven’t mentioned fertilizer applications as a solution for increasing potassium and phosphorus availability. That’s because it is likely your soil already contains adequate potassium and phosphorus. However, it’s not in a form your plants can use. When you have a thriving microbial community in your soil, the microbes do the work of cycling these nutrients into plant-available forms for you for free.

That is, as long as they stay fed.

Like you, microbes need energy to do their work. Carbon from organic matter is an important food source for soil microorganisms. When they have adequate food and favorable soil conditions, they can actively decompose organic materials and participate in nutrient cycling. 

BIOACTIVE LiquiLife+ Maintains Healthy Soil Microbes

The ST Biologicals mentors often recommend a regenerative ag product to help you feed and maintain your soil microbe community. BIOACTIVE LiquiLife+ contains a wide range of beneficial microorganisms that perform different functions within your soil, including nutrient cycling and pathogen suppression, to give your existing microbial population a boost.

Your soil may contain more potassium and phosphorus than your crops can currently access. Soil microbes break down organic matter, unlock potassium and phosphorus from inorganic matter, and deliver it to plant roots for uptake. BIOACTIVE LiquiLife+ can support these processes and help you get more from your soil before you spend money on additional inputs.

At ST Biologicals, we know productive soils are living systems. By supporting the biology beneath your crop, you can improve the way nutrients move through the soil and build a stronger foundation for crop health, nutrient efficiency, and long-term productivity. Get in touch with us to learn how to feed your microbes so they can feed your crops. We’re here to help you succeed. When soil speaks, we listen.

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Soil Potassium and Phosphorus FAQs