Back by popular demand, we welcome Lawrence Mayhew—chemist and humic substance specialist—to talk about the biology of thatch. Thatch is the result of an imbalance in the carbon-to-nitrogen ratio within the soil profile, often caused by the overuse of synthetic nitrogen. It can restrict air and water movement through the turf, fails to provide a usable carbon food source for microbes, and does not support a strong playing surface.
Lawrence begins our conversation with a review of what constitutes a good humic acid and why these substances are so important. However, the core focus of this podcast is the biology of thatch in turf systems and how we can biologically digest long-chained, ligneous carbon material into a usable carbon form known as humus.
He breaks down the three stages of thatch—the green, brown, and dark carbon layers commonly found in turf systems. The dark carbon layer is the most beneficial and can only be achieved through microbial digestion and the production of specific enzymes critical to this process.
As always, it’s a fascinating discussion packed with valuable information for anyone growing grass or cultivating any horticultural product. The chemistry, physics, and biology behind thatch digestion are complex, but with the right biological system in place, the turf industry is witnessing a shift away from mechanical aerification toward a natural process. The result: a healthier environment and a significantly easier life for turf managers.