I apply a powdered water soluble liquid iron for lawns to my own lawn. This powder is one I've been using for several years. It's very cost-effective and a little goes a long way. A bag contains 25kg. That's 25 full knapsacks at 20 litres a knapsack, so you can effectively get at least 400 sq metres out of one knapsack.. So this bag has the capacity to treat 10,000 sq metres (1 hectare!)
See the before and after of iron sulphate when applied to a lawn. The iron helps the grass retain a deep Green colour, while also controlling moss, and strengthening the walls of the grass blade, effectively making it harder and tougher through winter.
