Wherever in the world cabbage is grown, its high demand for nutrients leaves it vulnerable to nutrient deficiencies and susceptible to fungal and bacterial diseases. This has given rise to the practice of over-fertilizing the crop. New evidence on the benefits of using natural polyhalite fertilizer has shown how this use of Polysulphate boosts cabbage vigor and productivity.
The results of trials carried out by the International Potash Institute (IPI) in Brazil were presented recently at the 36th Brazilian Congress on Soil Science. They are summarized neatly in a poster available in English and Portuguese. They show that there is something to learn in order to cost-effectively and carefully boost cabbage yield.
A control was compared with applications of straight MOP and combinations of MOP and Polyhalite from 20%, 40%, 60%, 80% Polyhalite through to100% Polyhalite. Three main findings: vigor was seen to peak where 40-60% Polyhalite was used; Polyhalite significantly reduced leaf rot potential; and yield peaked with 60-80% Polyhalite application, even on high fertility soils.