76 



NATURE 



[April 8, 1920 



hamshire should end off at an anticline, probably 

 faulted, in the region about Melton Mowbray. 

 Such an anticline has an east-and-west trend, and 

 carries round the strike of the Coal Measures from 

 its g^eneral north-east-and-south-west to an east- 

 and-west direction. The Rempstone-Melton Mow- 

 bray magnetic disturbances, therefore, are inter- 

 preted as additional evidence of the existence of 

 a fault which in the underlying- Palaeozoic rocks 

 may have a considerable throw ; and it is 

 regarded as probable that a sill of dolerite is dis- 

 placed by this fault, or that an irregular mass of 

 dolerite is intruded along it. 



The hope is expressed by the author that a 

 like method of attack may prove to be of use as 

 a guide to the divining of the position of faults 

 beneath a cover of unconformable strata in other 

 districts — e.g. in concealed coalfields, where 

 dolerites or other rocks containing a high propor- 

 tion of magnetite are present. Unfortunately, 

 however, or fortunately from the point of view of 

 the coal miner, dolerites are not an invariable con- 

 comitant of. coal seams, and it therefore follows 

 that the use of the method in determining the 

 limits of concealed coalfields would appear to be 

 somewhat restricted. 



British Crop 



By Dr. Edward J 

 /^ROP production in Britain is carried on in the 

 ^ hope of gain, and thus differs fundamentally 

 from gardening, which is commonly practised without 

 regard to profit and loss accounts. Many poets from 

 times of old down to our own days have sung of the 

 pleasures to be derived from gardening. But only 

 once in the history of literature have the pleasures of 

 farming been sung, and that was nearly two thousand 

 years ago. 



Ah ! too fortunate the husbandmen, did they but know it, on whom, far 

 from the clash of arms, earth their most just mistress lavishes from the soil 

 a plenteous subsistence.— "Georgics," Bk. II., i., 458 et seq, 



"Did they but know it"! Even then there seem 

 to have been worries I 



This seeking for profit imposes an important condi- 

 tion on British agriculture : maximum production 

 must be secured at the minimum of cost. This condi- 

 tion is best fulfilled by utilising to the full all the 

 natural advantages and obviating so far as possible 

 all the natural disadvantages of the farm — in other 

 words, by growing crops specially adapted to the local 

 conditions, and avoiding any not particularly well 

 suited to them. 



From the scientific point of view the problem thus 

 becomes a study in adaptation, and we shall find a 

 considerable interplay of factors, inasmuch as both 

 natural conditions and' crop can be somewhat altered 

 so as the better to suit each other. i 



It is not my province to discuss the methods by 

 which plant-breeders alter plants ; it is sufficient to 

 know that this can be done within limits which no 

 one would yet attempt to define. The natural condi- 

 tions are determined broadly by climate and by soil. 

 The climate may be regarded as uncontrollable. 

 "What can't be cured must be endured." The 

 scheme of crop production must, therefore, be adapted 

 to the climate, and especially to the rainfall. 



The rainfall map shows that the eastern half of 

 England is, on the whole, drier than the western half. 

 In agricultural experience, wheat flourishes best in 

 dry conditions and grass in wet conditions ; the vegeta- 

 tion maps show that wheat tends to be grown in the 

 eastern and grass in the western part. The strict 

 relationship is that seed production is appropriate to 

 the drier, and leaf production to the wetter, districts. 



The great soil belts of England south of the Trent 

 run in a south-westerlv direction ; north of the Trent, 

 however, they run north and south. A heavy soil, like 

 a wet climate, favours grass production ; a light soil, 

 like a dry climate, is suitable for arable crops. The 

 great influence of climate is modified, but not over- 

 ridden, by the soil factor. 



The arable farmer grows three kinds of crops : 

 corn, clover or seeds hay, and fodder crops for his 



1 Discourse delivered at the Royal Institution on Friday, February 20. 



NO. 2632, VOL. 105] 



Production.^ 



. Russell, F.R.S. 



animals or potatoes for human beings. The same 

 general principles underlie all, and as corn crops are 

 of the most general interest (though not necessarily 

 of the greatest importance), they will serve to illus- 

 trate all the points it is necessary to bring out. We 

 have seen that wheat is cultivated more in the eastern 

 than in the western portion of the country. The 

 figures for consumption and production are as 

 follow^ : — 



Millions of Tons per Annum. 



Production in England Production in United 



and Wales Kingdom 



Consump- 

 tion in 

 United 



Kingdom 



Wheat 

 Barley 

 Oats 



1918 



1-2 

 20 



1919 



1-8 

 11 

 1-6 



Before „ 



war 19.4 '"^ '^'^ 



17 2 ft 20 



16 15 I-J 



3-0 45 4-2 



Before 

 war 1914 

 7-40 1-6 



I 96 1-2 



4 30 14 



During the war very serious attention was paid to 

 the problem of reducing the gap between consumption 

 and production. A working solution was found by 

 lowering the milling standard, retaining more of the 

 offal, and introducing other cereals and potatoes ; a 

 very considerable proportion of the resulting bread 

 was thus produced at home. But the war-bread did 

 not commend itself, and disappeared soon after the 

 armistice ; since then the consumption of wheat has 

 gone up, and the divergence between consumption and 

 production has again become marked. There is no 

 hope of reducing consumption ; we must, therefore, 

 increase production. Additional production may be 

 obtained in two ways : by increasing the yield per 

 acre, and by increasing the number of acres devoted 

 to the crop. 



The yield per acre is shown in the following table : — 

 Measured Bushels per Acre.^ 

 (,908-17) 



Average yield 

 per acre 



Highest re- 

 corded yield 



96 



- 80 



121 



England c„o.,-„d A good farmer 

 and Wales ^^otlana expects 



Wheat ... 31-0 39-9 40 to 50 



Barley ... 31-9 35-4 40 to 60 



Oats ... 393 389 60 to 80 



The average results include bad farmers and bad 

 seasons ; the good farmer expects to do considerably 



* Unfortunately the terms ''bushel" and ''quarter" (8 bushrls) lack 

 definiteness, being used officially in three diflferent senses and unoflRcially in 

 several others also. The following are some of the definitions of a bushel : — 



Official Statistics. 

 A definite 

 volume having 

 the following 

 average weight 

 lb. 

 Wheat ... 6i'9 

 Barley ... 537 

 Oats ... 39-3 



Corn Returns 



Act. 

 Volume occu- 

 pied by follow- 

 ing weight 

 lb. 

 60 

 50 

 39 



Grain Prices 



Order. 

 Volume occu- 

 pied by follow- 

 ing weight 

 lb. 

 63 

 55 

 42 



Frequent 

 Practice. 

 Volume occu- 

 pied by follow- 

 ing weight 



56 



