Caking, Clumping, and Clogging: Avoiding Bulk Mixture Headaches

:: Wednesday, November 15, 2017
Bulk blending is an efficient and advantageous way to apply micronutrients to your soil. Bulk blends give farmers the flexibility to prepare only the necessary amount of fertilizers with just the right ratio of nutrients for a given field. However, bulk blending can also cause headaches when issues including dust, caking, and product segregation arise.
What’s behind these annoyances? Let’s take a closer look.
  • Dust: Dust occurs when a product breaks down into powder, often during handling and transport. Dust can lead to wasted product, decreased air quality, and uneven application. Dust can also lead to caking, which renders the product difficult to use.
  • Caking: Caking occurs when fertilizer particles create contact points with each other that are typically formed by salt bridges, adhesion, or surface diffusion from porous granules.  A product with a high amount of dust can lead to caking when the dust comes into contact with moisture, such as through ambient humidity. The dust absorbs the moisture, becomes sticky, and the product clumps together.

    Caked fertilizer has expensive consequences. For example, caking can cause equipment to clog and wear out. It can also cause poor nutrient distribution in the fields, which can affect plant health and yields.

    Anticaking agents can help, but research has shown that these treatments are most effective if the fertilizer is well made. Specifically, the International Fertiliser Society found that anticaking treatments worked best when the treated fertilizers consisted of evenly shaped granules and at least 90% of the granules were more than 2.0 mm in size.
  • Segregation: Segregation occurs when inconsistent granule sizes and shapes cause a product to distribute unevenly in a blend and thus on the field as well. Ideally, the average size of granules is consistent within a given product as well as between all of the products in a fertilizer blend.

What’s a farmer to do?

When it comes to boron supplementation, look for a product with an average particle size greater than 2.0 mm and a uniform particle size distribution. (Particle size distribution describes the range of particle sizes within a given product. The more variable the particle size, the more likely it is to segregate when blended.)
Granubor® is a refined boron product carefully designed to prevent dust, caking, and segregation. Its average particle size is 2.8 mm, which makes it compatible with the granules in most NPK blends. It also has a uniform particle size distribution similar to common blends, further reducing the chances of segregation.
Its high abrasion resistance makes Granubor unlikely to degrade into dust during transport and handling, which in turn reduces the likelihood of caking.
Granubor will mix evenly into blends and distribute evenly on the field, providing the most consistent, high quality results. It’s a money saver, too, as less product is left as dust in the storeroom or caked in equipment.

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