When should I apply MOP (potash) and is broadcasting it enough?

Muriate of potash (MOP) supplies potassium, which the crop needs for grain or fruit filling, stem strength and stress tolerance, so it should not be an afterthought. Potassium does not move in the soil as freely as nitrogen, so like phosphorus it is generally better placed in the soil near the root zone rather than just scattered late on the surface. A common practice is to apply potash as a basal dose at sowing, and for longer or heavy-feeding crops to split part of it into a later application during the high-demand stage. Apply to moist soil or before irrigation so it dissolves and reaches the roots. Throwing it on top very late often means the crop benefits little. One caution: MOP carries chloride, so for chloride-sensitive crops a sulphate form of potash may suit better. For your crop's correct timing, split and whether MOP or another potash source fits, follow your KVK advice, base the dose on your Soil Health Card or soil test, and do not over-apply.