POLY4 is fully soluble and delivers nutrients effectively
All fertilizers are characterised by their solubility in water at a given temperature.
The solubility of POLY4, determined in a standard test over a range of temperatures , is compared to the water solubility reported for common fertilizers in Figure 8.
The water solubility of POLY4 is 27 g/l at 25°C corresponding to the amount of POLY4 that would dissolve in the plough layer of a moist, medium textured soil at a 10 t/ha application rate (Table 3).
Dissolution rate characterises the transition of a solid fertilizer into a solution. Figure 9 shows POLY4 in comparison to MOP, SOP and SOP-M at 20˚C. POLY4’s dissolution rate was similar to MOP, but slightly faster than SOP during the first 15 minutes.
Since POLY4 is a mineral, dissolution results in simultaneous nutrient release. Both tests demonstrated that all nutrients are available, with near full dissolution of its nutrient content within six hours (Figure 10).
Crops benefit from this characteristic as nutrients are delivered at a pace that is more compatible with their metabolic requirements.