Understanding Biofertilizers

An increasing number of plant fertilizer products touting microbes as the primary active ingredient are being marketed to growers. Claims are made that they’ll enhance anything from crop growth to nutrient uptake.

Matt Kleinhenz is a professor and extension vegetable specialist at the Ohio State University. He says biofertilizers, as one class of inputs, are very diverse.

"Do they begin with say, seaweed? Do they begin with a bacterium or fungus? Do they begin with a plant extract? Lots of different origins, lots of different end products, with all though, reported or thought to enhance crop growth or production, perhaps especially under sub-optimal conditions," says Kleinhenz. 

Oversight or regulation in the biofertilizer industry is inconsistent, and the effectiveness of many of these products is undocumented.

To protect yourself, there are some key questions to ask when you’re inquiring about a product, especially one containing microbes as a or the leading component.

"A: what data or information can you share with me regarding the expected outcomes? B: what linkage could they establish, if any, between the components of the product and the expected or reported outcomes? Is it reasonable to assume that applying this chemical could have this reaction, what are the stepping stones to go from component A to outcome Z?" he says.

He recommends looking at research developed by a third party if possible, and quality information that emphasizes on-farm outcomes over testing in much more controlled settings.