We’ve been getting a lot of questions at trade shows about the benefits of humate additions to turfgrass systems. Following is a rundown of what humates are and how they can benefit plants.
Humates or humic substances are fully decomposed remains of plant or animal organic matter. They are the most chemically active compounds in soils with large cation and anion exchange capacities, far exceeding clays. In general, they are very long lasting in soil, but the more intensively a site is managed, the faster they breakdown. This is one reason to add humic substances to your soil: to replace humus depletion in agricultural and horticultural soils.
Most humic products are derived from a mineral called leonardite, whose origins are not entirely understood. It is either an oxidized form of lignite or an accumulation of humic acids leached from topsoil by alkaline water into deeper strata of soil. Leonardite was discovered in North Dakota in 1919 by Leonard Dave, a University of North Dakota faculty member. It is also found in Utah and New Mexico. Leonardite is normally found very close to the surface near lignite deposits.
There are a few terms often thrown around when discussing humic substances; let’s take a look at them to try and clear up any confusion. Leonardite contains three types of organic substances:
- Fulvic acid – the fraction that is soluble in water under all pH conditions
- Humin – the fraction not soluble in water at any pH value
- Humic acid – the fraction not soluble in water under acidic conditions but is soluble at higher pH values
So, how do humates help plants? Again, the mechanisms for how these substances work in plants and soil are poorly understood, but research is being conducted worldwide (including some work funded by Calcium Products) in an attempt to help us understand the how and why. It is assumed, however, that the chelating properties of these substances are most likely responsible for enhanced nutrient uptake and retention in soils, as are their large cation exchange capacity values.
Humates have shown the following benefits in turfgrass situations:
- Improved germination
- Improved seedling vigor
- Enhanced nutrient uptake (N, P, K, Mg, Cu, Mn)
- Increased microbial actibity
- Increased root mass
It is important to note that much of the research done on turf has shown that humic substances, particularly leonardite, realize the greatest benefits when applied to sandy soils low in organic matter and CEC. Also, incorporation of these products into the soil further improved the beneficial aspects of humic substances. This means sand-based turf systems (sand-based putting greens, sand-based and sand-capped athletic fields and any turf system intensively topdressed with sand) can benefit from applications of humic substances. It would also be wise to time your applications with your aerification practices to help incorporate the product into the soil.
Calcium Product’s HumaCal, combines the benefits of humates, calcium and sulfur. The ingredients are combined through our proprietary manufacturing process before pelletizing to give you the benefits of easy application and immediate action in the soil.
Talk to your dealer about HumaCal and start on the road to healthy soil today!