How to fertilise your onion crop

Depending on the stage of an onion plant's development, the farmer needs to adjust the ratio of elements in their fertiliser mix, says Bill Kerr.

- 

Generally, basic fertilisation is similar for most vegetables; it is just the management of nitrogen that you need to vary to get the most out of your different crops. People often ask me which fertiliser to use for specific crops. It is simply a matter of getting a soil analysis done. This helps determine which nutrients are required for plant growth. In some cases, these nutrients also need to be in balance with one another. You then tweak the mix with nitrogen and perhaps trace minerals.

Nitrogen is the most leachable of the elements applied to a crop, so you shouldn't overdo the application during basic fertilisation prior to planting, as this could be wasteful due to leaching.