Apart from the growth-habits of the plant itself, the consideration that chiefly determines the routine of barley cultivation is the demand on the part of the maltster for uniformity of sample. Less care is required in its cultivation when it is intended for feeding live-stock. It is essential that the grains on the maltster's floor should germinate simultaneously, hence at the time of reaping, the whole crop must be as nearly as possible in the same stage of maturity. On rich soils the crop is liable to grow too rapidly and yield a coarse, uneven sample, consequently the best barley is grown on light, open and preferably calcareous soils, while if the condition of the soil is too high it is often reduced by growing wheat before the barley.
Barley (see Agriculture, Crops and Cropping) is a rapidly-growing and shallow-rooted plant. The upper layer of the soil must therefore be free from weeds, finely pulverized and stocked with a readily-available supply of nutriment. In most rotations barley is grown after turnips, or some other "cleaning" crop, with or without the interposition of a wheat crop. The roots are fed off by sheep during autumn and early winter, after which the ground is ploughed to a depth of 3 or 4 in. only in order not to put the layer of soil fertilized by the sheep beyond reach of the plant. The ground is then left unworked and open to the crumbling influence of frost till towards the end of winter, when it is stirred with the cultivator followed by the harrows, or in some cases ploughed with a shallow furrow. The seed, which should be plump, light in colour, with a thin skin covered by fine wrinkles, is sown in March and early April at the rate of from 8 to 12 pecks to the acre and lightly harrowed in. As even distribution at a uniform depth is necessary, the drill is preferred to the broadcast-seeder for barley sowing.
In early districts seeding may take place as early as February, provided a fine tilth is obtainable, but it rarely extends beyond the end of April. If artificial manures are used, a usual dressing consists of 2 or 3 cwt. of superphosphate to the acre at the time of sowing, followed, if the ground is in poor condition, by 1 cwt. of nitrate of soda when the plant is showing. Nitrogen must, however, be applied with caution as it makes the barley rich in albumen, and highly albuminous barley keeps badly and easily loses its germinating capacity. Farm-yard manure should also be avoided. After-cultivation may comprise rolling, harrowing (to preserve the fineness of the tilth) and in some districts hoeing. Barley is cut, either with scythe or machine, when it is quite ripe with the ears bending over. The crop is often allowed to lie loose for a day or two, owing to the belief that sunshine and dews or even showers mellow it and improve its colour. It may even be stacked without tying into sheaves, though this course involves greater expenditure of labour in carrying and afterwards in threshing.
There is a prejudice against the use of the binder in reaping barley, as it is impossible to secure uniformity of colour in the grain when the stalks are tightly tied in the sheaf, and the sun has not free access to those on the inside. In any case it must not be stacked while damp, and if cut by machine is therefore sometimes tied in sheaves and set up in stocks as in the case of wheat. The above sketch indicates the general principles of barley-cultivation, but in practice they are often modified by local custom or farming exigencies.
Barley is liable to smut and the other fungus diseases which attack wheat (q.v.), and the insect pests which prey on the two plants are also similar. The larvae of the ribbon-footed corn-fly (Chlorops taeniopus) caused great injury to the barley crop in Great Britain in 1893, when the plant was weakened by extreme drought. A fair crop of barley yields about 36 bushels (56 lb to the bushel) per acre, but under the best conditions 40 and 50 bushels may be obtained. The yield of straw is from 15 to 20 cwt. per acre. Barley-straw is considered inferior both as fodder and litter.
 Barley is occasionally sown in autumn to provide keep for sheep in the following spring.