1911 Encyclopædia Britannica/Agriculture/The Produce of British Crops
The Produce of British Crops.
Whilst the returns relating to the acreage of crops and the number of live stock in Great Britain have been officially collected in each year since 1866, the annual official estimates of the produce of the crops in the several sections of the kingdom do not extend back beyond 1885. The practice is for the Board of Agriculture to appoint local estimators, who report in the autumn as to the total production of the crops in the localities respectively assigned to them. By dividing the total production, say of wheat, in each county by the number of acres of wheat as returned by the occupiers on June 4, the estimated average yield per acre is obtained. It is important to notice that the figures relating to total production and yield per acre are only estimates, and it is not claimed for them that they are anything more. The fact that much of the wheat to which the figures apply is still in the stack after the publication of the figures shows that the latter are essentially estimates. The total produce of any crop in a given year must depend mainly upon the acreage grown, whilst the average yield per acre will be determined chiefly by the character of the season. In Table VII. are shown, in thousands of bushels, the estimated produce of the corn crops of the United Kingdom in the years 1890–1905.
Table VII.—Estimated Annual Total Produce of Corn Crops in
the United Kingdom, 1890–1905—Thousands of Bushels.
The largest area of wheat in the period was that of 1890, and the smallest was that of 1904; the same two years are seen to have been respectively those of highest and lowest total produce. It is noteworthy that in 1895 the country produced about half as much wheat as in any one of the years 1890, 1891 and 1898. The produce of barley, like that of oats, is less irregular than that of wheat, the extremes for barley being 80, 794,000 bushels (1890) and 62,453,000 bushels (1904), and those for oats 190,863,000 bushels (1894) and 161,17 5,000 bushels (1901). Similar details for potatoes, roots and hay, brought together in Table VIII., show that the production of potatoes varies much from year to year.
Table VIII.—Estimated Annual Total Produce of Potatoes, Roots
and Hay in the United Kingdom, 1890–1905—Thousands of Tons.
The imports of potatoes into the United Kingdom vary, to some extent inversely; thus, the low production in 1897 was accompanied by an increase of imports from 3,921,205 cwt. in 1897 to 6,751,728 cwt. in 1898. No very great reliance can be placed upon the figures relating to turnips (which include swedes), as these are mostly fed to sheep on the ground, so that the estimates as to yield are necessarily vague. Mangels are probably more closely estimated, as these valuable roots are carted and stored for subsequent use for feeding stock. Under hay are included the produce of clover, sainfoin and rotation grasses, and also that of permanent meadow. The extent to which the annual production of the leading fodder crop may vary is shown in the table by the two consecutive years 1893 and 1894; from only nine million tons in the former year the production rose to upwards of fifteen million tons in the latter, an increase of over 70%.
Turning to the average yields per acre, as ascertained by dividing the number of acres into the total produce, the results of a decade are collected in Table IX. The effects of a prolonged
Table IX.—Estimated Annual Average Yield per Acre of Crops in United Kingdom, 1895–1904.
|Year.||Wheat.||Barley.||Oats.||Beans.||Peas.|| Pota- |
| Rota- |
| Perman- |
spring and summer drought, like that of 1893, are exemplified in the circumstance that four corn crops and the two hay crops all registered very low average yields that year, viz. wheat 26.08 bushels, barley 29.30 bushels, oats 38.14 bushels, beans 19.61 bushels, rotation hay 23.55 cwt., permanent hay 20.41 cwt. On the other hand, the season of 1898 was exceptionally favourable to cereals and to hay. The effects of a prolonged autumn drought, as distinguished from spring and summer drought, are shown in the very low yield of turnips in 1899. Mangels are sown earlier and have a longer period of growth than turnips; if they become well established in the summer they are less susceptible to autumn drought. The hay made from clover, sainfoin and grasses under rotation generally gives a bigger average yield than that from permanent grass land. The mean values at the foot of the table-they are not, strictly speaking, exact averages-indicate the average yields per acre in the United Kingdom to be about 31 bushels of wheat, 33 bushels of barley, 40 bushels of oats, 28 bushels of beans, 26 bushels of peas, 43 tons of potatoes, 131 tons of turnips and swedes, 184 tons of mangels, 32 cwt. of hay from temporary grass, and 29 cwt. of hay from permanent grass.
Table X.—Decennial Average Yields in Great Britain of Wheat,
Barley and Oats—Bushels per acre.
Although enormous single crops of mangels are sometimes grown, amounting occasionally to 100 tons per acre, the general average yield of 181 tons is about 5 tons more than that of turnips and swedes. Again, although from the richest old permanent meadow-lands very heavy crops of hay are taken season after season, the general average yield of permanent grass is about 3 cwt. of hay per acre less than that from clover, sainfoin and grasses under rotation. The general average yields of the corn crops are not fairly comparable one with the other, because they are given by measure and not by weight, whereas the weight per bushel varies considerably. For purposes of comparison it would be much better if the yields of corn crops were estimated in cwt. per acre. This, indeed, is the practice in Ireland, and in order to incorporate the Irish figures with those for Great Britain so as to obtain average values for the United Kingdom, the Irish yields are calculated into bushels at the rate of 60 ℔ to the bushel of wheat, of beans and of peas, 50 ℔ to the bushel of barley and 39 ℔ to the bushel of oats. The figure denoting the general average yield per acre of any class of crop needs readjustment after every successive harvest. If a decennial period be taken, then—for the purpose of the new calculation—the earliest year is omitted and the latest year added, the number of years continuing at ten. Adopting this course in the case of the cereal crops of Great Britain the decennial averages recorded in Table X. are obtained, the period 1885–1894 being the earliest decade for which the official figures are available. It thus appears that the average yield of wheat in Great Britain, as calculated upon the crops harvested during the ten years (1896–1905), exceeded 31 bushels to the acre, whereas, for the ten years ended 1895, it fell below 29 bushels. A large expansion in the acreage of the wheat crop would probably be attended by a decline in the average yield per acre, for when a crop is shrinking in area the tendency is to withdraw from it first the land least suited to its growth. The general average for the United Kingdom might then recede to rather less than 28 bushels of 60 ℔ per bushel, which was for a long time the accepted average - unless, of course, improved methods of cultivating and manuring the soil were to increase its general wheat-yielding capacity.
- The higher yield of wheat in the later years of the 19th century appears to be largely attributable to better grain-growing seasons. The yields in the experimental wheat-field at Rotharnsted—where there is no change either of land or of treatment—indicate this. The following figures show the average yields per acre of the selected plots at Rothamsted over six 8-yearly periods from 1852 to 1899, and afford evidence that the higher yield of later years is due to the seasons:—
Bushels (of 60 ℔) Average of— per acre. 8 years 1852–1859 ... 283 8″1860–1867 ... 287 8″1868–1875 ... 271 8″1876–1883 ... 251 8″1884–1891 ... 297 8″1892–1899 ... 30 —————————— ——— 32″1852–1883 ... 273 16″1884–1899 ... 30 —————————— ——— 48″1852–1899 ... 281
The average of the first thirty-two years was thus 273 bushels per acre, of the last sixteen years 30 bushels, and of the whole forty-eight years 281 bushels.