MBFi’s Poly Technology

by Cloete Rossouw – Formulation Chemist & S.B. Coetzee – Plant Pathologist

When talking about polymerization, the first thought that comes to mind is plastic production or the lid of the Tupperware lunch box lying in the cupboard. In the agricultural industry, the same technology and methods are used to produce the product, but the type of raw materials is different from the plastics and petrochemical industry. The end results of the polymerization process produce a product whose effectiveness and characteristics changes remarkably.


The process of polymerization contains energetic reaction kinetics where the reaction temperatures can reach more than 150oC. The process also requires specialized equipment to make the coordination chemistry compatible. In the case of MBFi’s poly technology, this device is known as the cross-pipe reactor. The process is explained by the following figure using MBFi’s Poly-K-Phos as an example:

Figure 1: The polymerization is explained using a zipper.

According to Figure 1, two separate streams of raw reagents, phosphoric acid, and potassium hydroxide, are linked together by means of the cross-pipe reactor to form the polymerized product.

In short, the process works like a zipper that inserts each molecule in its right place to form the polymer chain by building a longer phosphorus backbone with the potassium that is bound on the “side branches”. This type of polymer chain looks like this:

Figure 2: Linear potassium polyphosphate chain

What are the advantages of a polymerized product?

  1. The product is more stable and less susceptible to environmental factors that can cause the product to volatilise or degrade.
  2. The product is more absorbable by the plant because the charges of polymerised products are neutralized and therefore it is not retained by the leaves or stomata.
  3. The product is available longer for the plant to absorb and the chance of phytotoxicity is reduced thanks to the slow-release effect of the poly-technology.

Results from the field Figure 4 indicates from the data generated by a trial in the vicinity of Delmas (MP) during the 2017/2018 season to show the value of Poly-K-Phos to our growers on soybeans. The treatments are divided as follows: A is at planting time, B is at V4 stage, C is at V8 stage and D is at R1. The mixture used was N:0, P:1, K:1. From Figure 4 it is confirmed that K and P are important elements in the cultivation of soybeans. Using conventional treatments increases the harvest yield by 229.5 kg/ha. With the use of a K and P foliar feeding, it is seen that there is an increased yield with the application of half the K and P with planting. The highest yield was achieved by applying 100 kg O:1:1 mixture at planting time and applying 20 L/ha Poly-K-Phos with V4 and V8 (40 L/ha in total). The yield increase was 500.8 kg/ha in total.

Figure 3: On the left there is no possibility of phytotoxicity, but on the right there is a possibility of phytotoxicity.
Figure 4: The value of Poly-K-Phos to our growers on soybeans.