April 8, 1920] 



NATURE 



177 



better, but he has many things in his favour : superior 

 knowledge, greater command of capital, and posses- 

 sion of good land ; he will, therefore, always stand 

 above the average. Even his results can be improved ; 

 the highest recorded yields show what can be done 

 with present varieties and present methods in 

 exceptionally favourable circumstances. The figures 

 givt> the measure of the scientific problem, which is 

 to discover what changes would be necessary in order 

 to bridge the enormous gap between the average and 

 the Ijfst. In three directions progress is possible; we 

 may modify the plant or the soil, or we may miti- 

 gate the effects of unfavourable climate. 



Before the soil can be brought into cultivation at 

 all it is necessary to carry out certain major opera- 

 tions — draining, enclosing, etc. — which have to 

 be maintained in full order. These lie outside our 

 present discussion ; we must assume that they are 

 properly carried out, which is by no means always 

 the ca>t'. (iivon adequate drainage, soil conditions 

 are profoundly modified by cultivation, which has 

 developed into a fine art in England and Scotland, 

 and is, indeed, far better practised here than in most 

 other countries. But it is an art, and not yet a 

 science ; the husbandman achieves the results, but no 

 one can yet state in exact terms precisely what has 

 happened. A beginning has been made, and a labora- 

 torv for the study of soil physics has been instituted 

 at Rothamsted and placed under Mr. B. A. Keen, 

 where we hope gradually to develop a science of 

 cultivation. For the present cultivation remains an 

 art, and, further, it is essentially a modern art. The 

 medieval implements, as shown 'in the Tiberius MS. 

 (eleventh century) and the Luttrell Psalter (fourteenth 

 century), were crude, and left the ground in an ex- 

 ceedingly rough condition. Great advances were made 

 throughout the nineteenth century. Robert Ransome, 

 of Ipswich, took out his first patent in 1785 to 

 improve the plough; he was followed in 1812 

 by Howard, of Bedford, and later by Crosskill, 

 Marshall, Rushton, Fowler, and others, who have 

 made British implement-makers famous throughout 

 the world. Given time and sufficient labour, the good 

 British farmer using modern implements can accom- 

 plish wonders in the way of cultivation. 



I'nfortunately, neither time nor labour is always 

 available. Ploughing is possible only under certain 

 weather conditions, and there are many days in our 

 winters when it cannot be carried out. Unless, there- 

 fore, a large staff of men and horses is kept, the 

 work often cannot be done in time to allow of sowing 

 under the best conditions. 



The early days of the life of a plant play almost 

 as important a part in its subsequent history as they 

 do in the case of a child. Illustrations are only too 

 numerous of the adverse effect of being just too late 

 for good soil conditions. One from our own fields 

 is as follows : — 



Work rompleted 



Yield ot wheat 



1016 

 Bushels rer a( re 



26-8 



the shape of the tractor, and has brought the promise 

 of a way out. 



The tractor has two important advantages over the 

 horse. First of all, it works more quickly. Its pace 

 is 3^ miles per hour instead of 2\ miles. It turns 

 three furrows at a time instead of one only ; on our 

 land it ploughs an acre in four hours instead of taking 

 nearly a day and a half, as required by horses. There 

 is no limit to the work it can do; even an acre an 

 hour is no wild dream, but may yet be accomplished. 

 It therefore enables the farmer to get well forward 

 with his ploughing during the fine weather in late 

 summer and early autumn, and thus to obtain the 

 great atlvantages of a partial fallow and of freedom 

 to sow at any desired time. On our own land our 

 experience has been as follows : — 



Dates of Completion of Sowings of Wheat and Oats. 



Year Wheat 



19 1 6 February 17 



1917 March 16 



191 8 January 26 



1919 



November 26 



Oats 



October 16I 



„ 17 -Horses onlv 

 „ 27J 



„ 5 Tractor 



Further, if the plough is correctly designed and 

 properly used, the tractor does the vk,ork fully as 

 well as horses — even the horse-ploughman admits that. 

 It therefore increases considerably the efficiency of 

 the labourer, which, as we shall see later on, might 

 advantageously be raised. The cost of working is 

 apparently less, though it is difficult to decide this 

 until one knows what the repairs bill will be. In our 

 case the cost is : — 



Cost of Ploughing per. Acre, Autumn, 1919. 



Just- in time ... Nov. 24, 191.:^ 

 Just too late ... Feb. 17, 1916 19-3 



The farm-horse will not be speeded up, but main- 

 tains an even pace of 25 miles per hour. According 

 to the old ploughman's song still surviving in our 

 villages, an acre a day is the proper rate : — 



We ve aU ploughed an a'^re. I'll ewear and I'll vow, 

 For we're all jolly fellows that follow the plough. 



But under modern conditions it is impossible to 

 get more than three-quarters of an acre a day ploughed 

 on heavy land, and the scarcity of teams threatened 

 to bring arable husbandry into a hopeless impasse. 

 Fortunately for agriculture, the internal-combustion 

 engine appeared on the farm at a critical moment in 



NO. 2632, VOL. 105] 



Labour 



Maintenance 



Oil and petrol 

 Depreciation and repairs 



Time taken 



By traclor 

 s. d. 



7 7 



6 3 

 21 6 



4 hours 



32 8 

 x\ days 



' The internal-combustion engine is only just at che 

 beginning of its career on the farm, and no one can 

 yet foresee its developments. It is being used at 

 present simply like a horse, and is attached to imple- 

 ments evolved to suit the horse. But it is not a horse ; 

 its proper purpose is to cause rotation while it is 

 being used to pull, and in some cases, indeed, this 

 pull is reconverted into rotary motion. 



The second great method of improving soil condi- 

 tions is to add manures and fertilisers. Farmyard 

 manure is more effective than any other single sub- 

 stance; it is likely to remain the most important 

 manure, and if available in sufficient quantity it would 

 generally meet the case. Realising its importance. 

 Lord Elveden generously provided funds for extended 

 investigations at Rothamsted into the conditions to be 

 observed in making and storing it. This^ work is 

 still going on, and is leading to some highly important 

 developments. 



Farmvard manure, however, is not available in 

 sufficient quantities to meet all requirements. The 

 chemist has long since come to the aid of the farmer; 

 he has discovered the precise substances needed for 

 the nutrition of the plant, and prepared them on 

 a large scale. Like cultivation, this is largely a 

 British development; it was in London that the 

 first artificial manure factory w-as established in 1842, 

 and for many vears the industry was centred in 

 this country. ' The fertilisers now available are as 

 follows : — 



