Clay minerals are perhaps the most diverse materials known to man. Their unique properties have seen them used in a wide range of products and applications, from consumer products to industrial refractories and much more.
One industry that takes advantage of the diverse properties of clay, is the agriculture industry, which has come to utilize clay minerals in a growing number of applications for the many benefits it can offer.
Here’s a look at how and why clay minerals are so widely used in the agriculture industry, and how producers can develop clay products to maximize their many benefits.
Benefits of Clay in Agriculture
Clay’s distinct and varying properties make it capable of accomplishing a variety of objectives that are valuable to the agriculture industry. Some of the key reasons for which clay is utilized in agricultural include:
A High Sorptive Capacity
Many clays boast a high sorptive capacity, which allows clay to serve the industry as both an adsorbent and an absorbent.
The excellent absorbency capabilities of some clays are used to improve water retention and moisture management in soils, particularly in arid regions. Similarly, their adsorbent qualities have seen them used in applications where targeting and capturing specific components is beneficial.
Binding Characteristics
Many clays, and particularly bentonites, exhibit characteristics that make them effective as a binding agent, bringing components together. As the agriculture industry relies heavily on wet granulation to produce many of its products, clays serve as an effective and economic (and inert) binding agent.
Controlled Release
The ability of clays to serve as a carrier or coating for agricultural chemical products gives producers the opportunity to control the active ingredient release rate, which has several critical implications across products in the industry.
Economically Viable
Clays are attractive from an economic standpoint, as in most cases, they are readily available at a low cost.
Environmentally Friendly
Clays can not only assist in applications that benefit the environment by reducing pollution and potential contaminants, but they are also generally recognized as an environmentally friendly material. As such, their use has become increasingly attractive as the focus on environmental sustainability strengthens.
Diverse and Modifiable
Clays exhibit significant variation in both type and deposit, creating a diverse range of potential characteristics. Further, clays are easily modified to control various characteristics, allowing producers to hone in on and enhance the precise qualities they’re looking for.
All of these benefits, as well as many more, have seen clay minerals used in a variety of agricultural applications.
Applications of Clay in Agriculture
The primary ways in which clay is employed in agriculture are outlined here.
Fertilizers & Soil Conditioners
Clay minerals are widely used in soil conditioner and fertilizer products, as carriers, additives, binders, and coatings.
As mentioned, clays, when used as a granular carrier or coating, can promote the slow- or controlled-release of active ingredients. By making the release rate of the active ingredient more gradual, the potential for nutrient runoff (in the case of fertilizers) is reduced. In addition to reducing nutrient runoff, this controlled release rate can also be used to ensure the crop is fed over time, as opposed to all at once, which could potentially damage the crop or limit its productivity.
Clays, particularly bentonite, are also recognized for their ability to improve water retention when used in fertilizer products. This quality is especially beneficial in arid regions where moisture retention is challenging, but critical to soil health and successful crop production.1
Clays such as bentonite and kaolin may also serve as a diluent in fertilizers, reducing the concentration of elements. They can also be used as a means of improving flowability in products such as ammonium nitrate. 2
These qualities are likely to see clay’s use in the sector grow, as the market for specialty fertilizers and soil amendments expands.
Pesticides & Herbicides
For the same reasons clay is effective in fertilizer products, it is also beneficial when working with pesticides, herbicides, and insecticides.
Often, these chemicals are in the form of a liquid or sticky paste, making direct use challenging. By impregnating granular clay with the active ingredient, handling and application become much more easy and predictable, fostering optimal ingredient delivery. The subsequent slow-release quality of the product also then reduces the potential for such chemicals to migrate into surface or groundwater.
As in the case of fertilizers, clay may also be used as a way to dilute these concentrated materials that could otherwise be harmful to the crop or the handler if applied in full concentration.2
Additional research on clays in this sector looks promising; clays are showing potential in reducing the volatility and photodegradation of pesticides, which would further be helpful in decreasing the environmental risks associated with their use. 3
Animal Feeds
While clays first served the animal feed industry as a binding agent, assisting in pellet formation, they were later recognized for the many additional benefits they can offer.
Clay has shown to be an effective adsorbent for harmful mycotoxins in animal feed. Mycotoxins in animal feed can cause a number of serious issues, putting animal health and productivity at risk. Further, they have the potential to make animal-derived foods unsafe for human consumption. Instead of being absorbed in the digestive tract, clays can capture these undesirable components and carry them out of the body. 4
Clays have proven to have other benefits as well, including slowing the speed at which food moves through the digestive system, ultimately improving digestion.4
Other studies have illustrated clay’s ability to reduce acidity in the rumen of cows, improve the degradability of feedstuff, and even increase feed efficiency, thereby increasing egg production in chickens, weight gain in swine and cattle, and milk yield in dairy cows.2
As can be seen, clays have almost unlimited potential in agriculture products, serving to manage water in soil, capture and hold undesirable components, improve the efficiency of agricultural chemicals, and more. And while this diversity is promising, it can also make developing such products challenging.
Developing Clay Mineral Products for Use in Agriculture
Depending on the product and production process, clay may be incorporated into agricultural products as a carrier, coating, binder, or additive in the formulation, all of which pair well with the often-used wet granulation process (also known as agitation or tumble-growth agglomeration). Wet granulation is a popular choice in agriculture for the many benefits offered by the rounded granule the process yields.
The dynamic between the unique clay source and approach to wet granulation is of crucial importance, as all materials respond differently to the technique. This makes assessing the feasibility of the intended process, as well as gathering the process and equipment data necessary to produce the desired results essential. For these reasons, the FEECO Innovation Center offers comprehensive wet granulation testing capabilities, with batch- and continuous pilot-scale options available.
Through testing, experts in the Innovation Center can fine-tune formulation, granulation process and equipment parameters, and refine product characteristics, whether clay will be incorporated as a carrier, binder, coating, or additive.
In addition to various types of granulation equipment, batch- and pilot-scale calciners are available to test clay calcination. As drying clay minerals is a critical step in preparing a clay for market, dryer testing is also available.
Please note: While the Innovation Center does not accept pesticides for testing, we do offer a variety of rental equipment to accommodate testing needs.
Conclusion
As a result of the diverse range of benefits it can lend, clay has become a key material in the production of agriculture products such as pesticides, fertilizers, animal feed, and the like.
As the premier expert in wet granulation, FEECO assists customers in taking their agricultural products from concept to commercial-scale production, with support for every step of the way. FEECO has been serving the unique needs of the agriculture industry – clay products included – since 1951, through process and product development services, custom equipment manufacturing, and parts and service support. For more information on our clay experience, contact us today!