Although, from its present position in British agriculture, wheat would hardly appear to be a crop of prime importance, yet the fluctuations in acreage must be observed with great in terest ; they largely indicate the prosperity or adversity of arable cultivation on heavy clay soils, particularly in the eastern and southern portions of England, where climatic conditions favour the ripening and harvesting of a good sample of grain. Wheat is the principal source of revenue from arable crop pro duction on heavy land. This class of soil is unsuitable for other cash crops, such as potatoes, sugar beet or barley, which enable the light land farmer to continue arable cropping with more or less satisfactory financial results. The conversion of arable land to permanent grass in Great Britain has been closely associated with the abandonment of wheat cultivation on heavy soils; and it may be suggested that the revival of tillage in England can come about only with the return of more renumerative prices or less costly production of the wheat crop.
The close connection between wheat prices and the area under tillage may be illustrated by the fact that in the years 1871-75, when wheat averaged 12s. gd. per cwt., there were 14,766,000 acres of arable land in England and Wales, of which nearly 25% were devoted to wheat. With the decline in price to 6s. 6d. per cwt. in 1901-05, however, the arable area had diminished to 11,914,000 acres, and of this less than 14% was cropped with wheat. The percentage devoted to wheat in 1871-75 and 1901-05 respectively indicates that it is the wheat-growing class of land that has gone out of arable cultivation.
Wheat is regarded as a heavy land crop more because it excels the other cereals on strong soils than because of its preference for this class of land. By suitable manurial treatment heavy yields can be obtained from light soils also, as is the case in Norfolk, parts of Lincolnshire, Lancashire and the Lothians, where wheat occupies a regular place in light loam farming. Although her average yield is very high, Denmark has no land sufficiently strong to comply with the English conception of typical wheat and bean soil.
In Britain, wheat cultivation is conducted under the most favourable climatic conditions on the drier eastern side of the country. While conditions on the western side are favourable to the vegetative development of the plant, wet weather in August and September frequently impedes the harvesting of the crop and injures the milling quality of the grain. As regards temperatures, the warmer summer conditions of the southern counties of Eng land cause the crop to ripen a little earlier there than in the Lothian counties of Scotland; and while this does not ensure a higher yield per acre, it produces a better quality of grain for milling or for seed, and the earlier removal of the crop favours autumn tillage operations.
Little wheat is grown in Britain as far north as Aberdeen, al though in Scandinavia and Russia this cereal is cultivated in latitudes beyond that of the Shetland islands. High altitudes in Britain, being associated with heavy rainfall and late ripen ing, are not favourable to wheat growing. In Derbyshire, for example, this crop is rarely cultivated at elevations higher than 600 ft., except on southern slopes where the limit may be Boo ft. In the more southern latitudes of the Alps, however, wheat is grown at altitudes exceeding 3,00o ft. Provided that sufficient moisture is available, wheat in one or other of its several forms can be grown in any latitude between the northern limits above mentioned and that of about 5° from the equator.
The fact that more than 8o% of the wheat consumed in the United Kingdom comes from overseas has been frequently stated to be a weakness in British defence organisation, but is not at present looked upon as liable to incur shortage of bread corn in peace times. Except for a short period during and immediately after the World War, it has not recently been part of the na tional policy to induce the British farmer to grow wheat instead of grass. Although the possibility of serious competition with other countries similarly dependent on imported supplies of bread stuffs is commonly regarded as too remote for consideration, it is nevertheless deserving of notice that Eastern races are tending more and more to replace rice by wheat in the national ration.