Fertilizers are soluble salts which can increase soil water salinity thereby increasing soil EC. In our studies, POLY4 and other fertilizers increased soil EC (as measured after harvest at the higher application rates), but in no instances were the increases sufficient to cause crop damage.
An example of the effect of POLY4 application on soil EC for several crop trials is provided in Figure 13. The study shows that even at high K2O application rates, soil EC is well within the plant tolerance level for a range of sensitive crops. Depending on soil type and climate, the effect of POLY4 on soil EC appears to be limited.