Can a foliar micronutrient spray fix a deficiency faster than putting it in the soil?

For a standing crop already showing a micronutrient deficiency, a foliar spray is usually the faster rescue, while soil application is the better long term and basal correction. The reason is that a foliar spray puts the nutrient directly onto the leaf where it is absorbed within days, which is ideal when the crop is mid-season and you need a quick green-up, and it also dodges the soil locking up the nutrient. This matters a lot for iron, zinc and manganese on high pH soils, where soil-applied micronutrients often get tied up and wasted. Soil application, done at sowing or planting based on your Soil Health Card, is the way to prevent deficiency in the first place and to feed the heavy macronutrient demand that sprays cannot fully cover. A practical plan is: apply micronutrients to soil at sowing per your card to prevent the problem, and keep foliar sprays as the mid-season fix if symptoms still appear. Always confirm the deficiency with a soil or tissue test first, because spraying the wrong nutrient wastes money and can scorch leaves. Keep foliar concentrations low, such as around 0.5 percent for most micronutrient sulphates, follow your local KVK on the exact product and timing, and do not over-apply.