A speculative discussion of some problems arising from the use of ammonium nitrate fertiliser on acid soil.

Some personal farming experiences are described, and attention is drawn to four anomalies associated with the use of ammonium nitrate. These can be explained if the changes that took place in the formulation of fertilisers around 1960 have led to acidic soils becoming depleted in calcium, and if crops growing in high nitrogen conditions take up their nitrogen as ammonium. It is concluded that the fertiliser recommendations that have been formulated at Rothamsted are unsuitable for use upon acidic soils in wetter parts of the UK because they result in the soil becoming excessively anaerobic so that the balance of nutrients becomes unsuitable for optimal plant and animal growth.