From 1950 to 1978 the total N used in UK increased five times, the K was doubled, but P used changed little. Prices increased by 5 to 8 times, fertiliser concentrations increased, granulation became universal, liquids secured a small place, and high-nitrogen types came to dominate the compound market.
Recommendations for using fertilisers are much more comprehensive than in 1950. Changes in fertilisers used on the principal arable crops and grassland from 1950 to 1978 are discussed, current use is compared with recommendations. The largest changes are in N; grassland received about a third of the total N used in 1958, but half of the much larger total used 20 years later.
In future there are likely to be some small increases in the N used on arable crops. Considerable increases in the total quantity of N used on grassland will be justified as more farmers intensify their management. There seems to be little need to increase the total amounts of P and K used but there is scope for improving efficiency by redistributing the supplies to arable crops and to grass so that dressings fit more closely to the needs of farming systems used, and to reserves in the soils.
G W Cooke, CBE, PhD, FRIC, CChem, FRS, Agricultural Research Council, London.
28 pages, 23 tables, 26 references.