Farmers purchasing protected urea fertiliser at present should be aware that if this fertiliser is to be used next March or April, the inhibitor used to stop ammonia loss may not be as effective.

Different products carry different shelflifes, some of which are up at around six months from the time the inhibitor was applied. This is one of the reasons why protected urea is sometimes hard to purchase.

Many merchants will only order stocks which farmers have placed orders for so that the product will not be left unused.