Healthy turf. The most important end result for grounds crew managers. While there are a variety of ways to "achieve" healthy turf, it's maintaining the vitality of the turf, especially turf that sees constant wear and tear and/or the changing of seasons, that proves to be a challenge.

Azospirillum – the microbial impacting plant growth

Healthy turf. The most important end result for grounds crew managers and sod producers. While there are a variety of ways to ‘achieve’ healthy turf, it’s maintaining the vitality of the turf, especially turf that sees constant wear and tear and/or the changing of seasons, that proves to be a challenge. 

The vitality of the turf often relies on a variety of chemical inputs – but does it need to? For turf managers looking for a more natural solution to healthier, hardier turf, microbial inputs can be a solution to promoting turf growth while minimizing usage of fertilizers and pesticides. There can be as many as 10,000 different microorganism species existing in a gram of soil, and there are bacteria that can help protect and nourish plants if present in large enough numbers. Microbial inputs can help increase the population of helpful microorganisms in the living soil. 

Azospirillum is a bacteria that has in more recent years become known for its effects on non-leguminous crops.  First isolated from soil in the Netherlands in 1925, the bacteria was forgotten for a half century before its rediscovery in the 1970s in Brazil.  Acting as a nitrogen “fixer,” Azospirillum harvests nitrogen from the air and soil and delivers it to the plant. While most microbial inoculants are applied to improve plant nutrition, Azospirillum has yielded favorable results in improving root structure year over year and when stabilized in high enough concentrations, it can impact plant growth. Microbes also aid the soil’s efficiency of potassium and phosphorous uptake.

Specifically, Azospirillum takes atmospheric nitrogen (N2) from the air and converts it to forms of nitrogen usable by the plant. The first step in Azospirillum colonization in a plant is the absorption step, consisting of a rapid, loose and reversible binding of Azospirillum to the root.  The second step is the anchoring phase, in which the bacterium becomes irreversibly bound to the root’s surface. During these first few days of association, the bacterium colonizes root hair zones of both primary and secondary roots. This natural process means users may decrease their usage of traditional nitrogen fertilizers, saving both time and money. It also means the plant can become less dependent on manufactured nitrogen fertilizers and more sustainable through atmospheric nitrogen. Essentially, users will “harvest from the sky” versus harvesting from the ground.

University research has identified what numerous microorganisms can do, from controlling insects, to stimulating plant growth. Relatively few microorganisms, however, have been realized into reliable and functional products for the market. Cost of final product, storage and shelf life all contribute to the lack of commercialization. Minnesota-based TerraMax has discovered an advanced stabilization technology that can keep Azospirillum viable for over one year.

Azospirillum products have been proven in university studies to increase rooting.  Products can be applied either as a dry formulation on grass seeds, or sprayed as a liquid and watered into existing turf.  A University of Nebraska-Lincoln study in 2006 using TerraMax products showed a 69 percent increase in rooting in bluegrass using a dry Azospirillum formulation on grass seeds and a 108 percent increase in rooting using a liquid formulation.    


Users across the country have found value in including Azospirillum in their golf courses, sports fields and sod farms.  Not only are they seeing healthier, more resistant turf, they are also reducing their usage of expensive pesticides and fertilizers.  “I have reduced my nitrogen inputs by 30 to 50 percent. I get better color and disease resistance, and can space my pesticide applications a few extra days,” says Dan Wolner, Superintendent of Lake Panorama National Golf Course in Iowa. 

Turf managers, golf superintendents and sod producers are well aware that healthy turf begins at the root. While parent material of soil, climate, topography and vegetation contribute to the function and performance of the plant, “fixing” nitrogen with roots, as Azospirillum does, greatly increases root structure; a key factor in better resisting changing climate conditions and daily wear and tear experienced by turf surfaces. Studies have shown an almost 75 percent increase in Kentucky Bluegrass root volume six weeks after planting. Those caring for turf, now have a more consistent and natural solution for treating their grounds or sod with Azospirillum.

For more information on Azospirillum and its benefits visit TerraMax develops and distributes natural microbial products designed to increase yields of agricultural crops and improve root structure and appearance of turf while minimizing the use of petrochemical and mined fertilizers.  TerraMax products rely on an industry-exclusive technology to stabilize the Azospirillum bacteria for longer shelf life and effectiveness. 


Doug Kremer is the founder and CEO of TerraMax.  With over 30 years of experience in agriculture and horticulture, including developing patented technology for the formulation of microbial technologies, he is the driving force behind product development at TerraMax.