Three critical elements that crops need and how TerraMax is helping access them

Feb 10, 2023 | How it works

Why do we eat a balanced diet? Humans need to eat a varied diet from each food group to get a range of essential nutrients for overall good health. Maybe you’re somebody who tracks your intake of macronutrients, or nutrients that we need in large quantities, for athletic training or health purposes, or perhaps you know bananas are great for sustained energy.

Plants need macro and micronutrients for their health, just like us. Nitrogen, phosphorus and potassium are three macronutrients that plants need to support their basic cellular processes. But unlike us, they are stuck in one spot and can’t hunt for whatever nutrients they need. And according to the Nature Education Knowledge Project, “nutrient deficiency can have a significant impact on agriculture, resulting in reduced crop yield or reduced plant quality.”

So how do plants get nutrients?


One microbe does not fit all

Like many aspects of plant health, the answer lies in the ground, specifically at the plant’s roots and in the surrounding microbiome. For example, you’re probably familiar with the critical role of nitrogen in crop health. Plants require bacteria to pull nitrogen from the atmosphere and make it available to the plants in the soil. This is called nitrogen fixation and there are ways to harness this process with soil microbes. The scientists at TerraMax have been researching and developing this for decades.

Nitrogen, phosphorous and potassium, or “the big three,” as TerraMax CEO and scientist Doug Kremer refers to them, are the elements in highest demand to drive plant growth and crop yield.

When it comes to fixing nitrogen in the soil, there are no better microbes for the job than Azospirillum for corn and Bradyrhizobium for soybeans. However, microbes are not generalists. “Particularly in the soil environment, microbes operate as teams,” says Kremer. “One microbe will not do everything.”


The microbial heroes of nitrogen fixation, Azospirillum and Bradyrhizobium, have evolved over eons in the soil microbiome while doing a specific job. “It’s very energy-intensive for a cell to fix nitrogen,” says Kremer. “There are limits to how much nitrogen a single microbial family can fix and persist through an entire growing season to help that plant grow and provide nitrogen.”

So where does that leave phosphorus and potassium?


The role of phosphorus and potassium

Our bodies burn food for energy by converting food into adenosine tri-phosphate, then they break the phosphate bond in ATP to release energy. Phosphate contains phosphorus, an element involved in powering our body cells and plant cells, but that’s not all.

“Phosphorus is involved in many structural aspects of plant-related molecules,” explains TerraMax’s director of research, Dr. Molly Tillman. “Another big one is turning on or off different cellular functions driven by either adding or attaching phosphorus.”

Potassium is also involved in a plant’s structure. “Think: building blocks,” says Kremer.

“Potassium is critical to life’s basic functions,” says Tillman. Cell growth, cell proliferation, the opening and closing of stomata, producing and moving proteins, and other functions involve potassium.

While just as critical as nitrogen to plant health, phosphorous and potassium differ from nitrogen in one crucial aspect: They are not available in the atmosphere. And microbes that fix nitrogen are too busy doing their job and cannot facilitate mobilizing phosphorus and potassium into a plant.


TerraMax continues to tinker

While TerraMax has cracked the code for harnessing nature’s processes with their products to cover nitrogen, many farmers are in the market for products that will help their crops better access phosphorus and potassium.

The search for the right microbe for the job is daunting, but the TerraMax team has done it before.

“We start by talking to other experts in the field,” says Tillman. “We comb through scientific literature and look through microbial candidates that might perform these functions. Then we screen them in the lab.”

Currently, Tillman is working with species to include products targeting phosphorus mobilization. “These steps are all about looking at how our formulation technologies affect our ability to take microbial activity and deliver it as a product a grower can use.”

Kremer emphasizes this process can take a long time. “We do tight science to ensure we link as strongly as possible to the microbial functions we need.”

Once the science shows the microbes do the job, the TerraMax researchers must determine the feasibility of using them as a product. Any new product must be packaged, shelf-stable and effective for farmers.

“One thing that we are always targeting is yield increases,” Tillman says.

Every question about how a specific microbe will behave in the lab, formulated product and soil comes back to the benefit to the farmer. “That’s the driving force behind what becomes a product,” Tillman says. “It always comes back to yield increase and return on investment.”