Ferrous sulphate is commonly used in turf/lawn culture as a moss killing agent. Iron deficiency in pasture & crops is rare – where there is a deficiency it is usually related to low pH and poor drainage. This fertilizer comes in water soluble form so can be sprayed onto marginally deficient crops when or sometimes used as a soil acidifying agent. Market gardeners often include Fe in mixes as it enhances the green colour in plant leaves.