Not All Wetting Agents are the Same – Some Key Differences
The terms “surfactant” and “wetting agent” are often used interchangeably, but they are not synonyms. All surfactants are wetting agents; however, not all wetting agents are surfactants. There are products other than surfactants that can reduce the surface tension of liquids, allowing them to penetrate and spread through the ground. Here are some of the differences to keep in mind.
The Difficulty in Choosing Wetting Agents
Wetting agents are some of the most common products used on golf courses. These products allow water to penetrate the surface of the ground and spread evenly, which provides a lush, equally-moistened course for golfers. You already know that not all herbicides and fungicides are the same; they are grouped into categories to make it easier for you to decide which ones will best suit your needs. Unfortunately, the same categorization simply does not exist for wetting agents, so it is up to you to do the research and find the best product for your course.
Different Surfactant & Wetting Agent Types
Understanding the key differences between wetting agent and surfactant types is the first step in choosing the right product for your needs.
- Anionic & Anionic Blends – Anionic wetting agents are surfactants that have a negative charge. If you need quick, thorough wetting, this is the option for you – but be aware that it can be phytotoxic if applied too heavily or too quickly. What’s more, the negative ions can actually force clay particles apart, which can be problematic if your course’s soil consists of fine clay.
- Nonionic Surfactants – There are several different types of nonionic surfactants available, and each one offers slightly different benefits and properties.
- Block Copolymer Surfactants – This is the most common wetting agent used in turf management because they are safe for fine soils, they make soil less water-repellant, and they improve the moisture available to plants and grass.
- Multibranched Regenerating Wetting Agents – These offer up a variety of molecular weights which make them longer-acting than other wetting agents. As the larger molecules biodegrade, lighter-weight molecule continues to offer moisture management benefits.
- Humic Substance Redistribution Molecules – This wetting agent was designed primarily to make the top one or two inches of soil more penetrable by reducing hydrophobic associations.
- Alkyl Polyglucoside Surfactants – These are natural surfactants made from sugars and fatty acids. They are also designed to make soil less water-repellant, but the biggest benefit is their ability to allow better infiltration than other wetting agents.
- Modified Methyl Capped Block Copolymer – This wetting agent creates a much thinner, but far more continuous film of water around individual soil particles. As a result, air-to-water ratios improve, allowing for better turf growth.
- Cationic Surfactants – Though they are surfactants, these are not typically utilized for soil wetting. These surfactants are highly disinfectant, which is toxic to plants when it is applied at a rate that would actually be useful for helping moisture penetrate hydrophobic soil. In fact, there are some reports showing that repeated use can actually make soils even more water repellent.
Of the three major types of surfactants and wetting agents, it is important for turf managers to pinpoint their unique needs. Nonionic surfactants, and namely block copolymer surfactants, are the most popular on golf courses because they offer several key benefits with very little risk.