By technical definition, chelation is when a molecule binds to a metal ion in a stable complex. In agriculture, chelating agents are often used to bind and supply key metallic nutrients to crop plants so that they can absorb them more effectively. This allows the grower to get maximal benefit from their fertilizer investment. Common metal ions include calcium, iron, magnesium, potassium and zinc. Examples of common chelating agents used in agriculture include EDTA and polymers based on amino acids or derivatives, like Soltellus™.
Let’s take a deeper dive into these two chelating agents to see how they compare and contrast.
Chelators: Balancing Nutrient Catch & Release
Chelating agents are not created equally. The two types mentioned vary greatly in their ability to capture, hold, and release key nutrients.
EDTA is the most common chelating agent used in agriculture. It is also admittedly the strongest chelator. In fact, it is arguably too strong of a chelator, holding nutrient ions too tightly which can impede the process of release of nutrients to plants.
Other potentially negative impacts of EDTA use include:
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- Poor degradation in soil
- Long persistence and bio-accumulation
- Higher concentrations can be phytotoxic to plants
- Mobilization of heavy metal ions from soil into water
- Decreased growth and potential harm to beneficial soil organisms
- Applications mainly limited to on fertilizer
- High cost
Because of these negative properties, there is much desire among agricultural scientists to find more eco-friendly alternatives to EDTA. Enter Soltellus™!
Soltellus™ is a polymer product based on aspartic acid, a naturally occurring amino acid. It has a Cation Exchange Capacity (CEC) of approximately 100. As you know, most soils have a CEC of anywhere from single digits to low-mid 20s. Thus, Soltellus™ can attract, capture, and hold nutrients more strongly than soil, making it an effective hub of nutrient ion transfer in the root zone. However, this attraction is not so strong that plant roots cannot readily access those nutrients to fuel plant growth, development and yield.
This perfect balance of catch and release of nutrients is what makes Soltellus™ so ideal as a chelating agent for today’s agricultural production.
Soltellus™: Chelate Responsibly!
Besides offering the perfect balance of nutrient catch and release, Soltellus™ also offers the following environmental and plant health benefits over EDTA:
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- Totally biodegradable within the season of use
- No persistence, residues, or bio-accumulation
- No phytotoxicity to plants
- No adverse effects on soil microorganisms
- Application flexibility (on/with fertilizer, in soil, foliar—ground or aerial)
- Economically priced
To learn more about Soltellus™, visit www.dober.com. Download our free Soltellus™ Agronomy eBook which describes this optimal chelator in more detail, including a section with agronomic efficacy data.
