December 25, 1919] 



NATURE 



421 



THE BRITISH ASSOCIATION AT 

 BOURNEMOUTH. 



SECTION M. 



agriculture. 



Opening Address (Abridged) by Prof. W. Somek- 

 viLLE, D.Sc, President of the Section. 



During the past four years — or since the ploughing 

 programme began to tal-:e shape — grass-land has been 

 officially cold-shouldered in no small degree. The 

 cause was obvious and the reasons were good. The 

 result of compulsory and voluntary ploughing has been 

 that, whereas in 19 14 the total area in Great Britain 

 under temporary and permanent grass (hay and pas- 

 ture) was practically 21.500,000 acres, it was barely 

 19,500,000 acres in 191S, a reduction, namely, of about 

 2,000,000 acres. During the same period the arable 

 area, other than temporary grass, increased from about 

 10,500,000 acres to 12,500,000 acres. In Ireland 

 during these years the area under grass (permanent 

 and temporary) fell from about 12,500,000 acres to 

 less than 11,250,000 acres. The United Kingdom at 

 the present time comprises about 30,500,000 acres of 

 permanent and temporary grass and 15,500,000 acres 

 of land under crops other than grass and clover. 

 This is over and above some 16,000,000 acres of 

 mountain land used for grazing. 



A considerable proportion of the grass-land of this 

 country is of so high a quality that any improvement, 

 and certainlv any economic improvement, is hard of 

 accomplishment. Satisfactory as are the high-class 

 pastures of this country, it by no means follows that 

 there is nothing more to learn about them. It is 

 often very difficult to determine the factor or factors 

 that go to the making of high-class pastures. Such 

 pastures are to be found on most of the geological 

 formations of this country ; they are met with north, 

 south, east, and west; and even altitude, within the 

 limit of at least 700 ft., seems to have little effect. 

 .•\n immense amount of attention has been given to 

 the botanical composition of the herbage of the more 

 famous of the pa'stures of Britain. The result that 

 emerges most conspicuously from these researches is 

 that one may have a dozen pastures which are 

 about equal in feeding value and yet may vary 

 widelv in respect of botanical composition. Thus 

 Freaiii found that in the case of forty-eight English 

 and eight Irish pastures, each of which was the 

 "best" in the district selected, the Graminea might 

 be as low as 11 per cent, and as high as 100 per 

 cent. ; Leguminosae might be entirely absent or as 

 high as 38 per cent. ; while of miscellaneous herbage, 

 most of which would be designated as "weeds," there 

 might be none or up to 89 per cent. As regards 

 individual genera and species, Fream found, for 

 instance-, that .\grostis was almost always present, 

 and on five occasions was the most abundant plant; 

 while Holciis lanatus gave an almost identical result, 

 Bv a different method Carruthers arrived at a very 

 similar conclusion. The latter also found that 

 Hordeum pratense was the most abundant species on 

 what is perhaps the finest grazing in England, 

 namelv, Pawlett Hams, near the mouth of the 

 Parret, in Somerset. This investigator even found 

 that on one of the " famous ancient pastures of Eng- 

 land " the predominant grasses were Florin and 

 Hassock, and in this connection makes the following 

 remark, " In this field the hassock-grass, which made 

 up a large proportion of the pasture, was freely eaten, 

 and the cattle were in good condition." 



In Hall and Russell's investigations .\grostis and 

 Holcus might on occasion each exceed 20 per cent., 

 and it is stated that "wherever Holcus lanatus occurs 

 NO. 2617, VOL. 104] 



it is more abundant on the fatting fields." Even 

 miscellaneous herbage could bulk more than 29 per 

 cent, on a pasture so good that it could fatten five 

 bullocks on four acres without cake. Armstrong 

 found in a field representative of "the richest type 

 of old grazing land found in the Market Harborough 

 district ' that, amongst grasses, Foa annua came 

 second (123 per cent.) in point of abundance. There 

 will be general agreement that four of the grasses 

 just mentioned, Fiorin, Yorkshire Fog, Squirrel Tail, 

 and Hassock, are accounted "bad," and yet it is 

 hard to apply this term to plants which are the most 

 abundant constituents of some of the finest pastures 

 in England. While there is much that is disconcert- 

 ing in these investigations, some facts do emerge with 

 satisfactory consistency: — (i) 1 hat the great majority 

 of high-class pastures contain a large proportion of 

 perennial ryegrass and white clover ; (2) that crested 

 dogstail is almost always present, though rarely pre- 

 dominant; (,3) that meadow fescue is practically 

 negligible; and (4) that of the two Poas, pratcnsis 

 and trivialis, the former is very rare, while the latter 

 is very common. 



The obvious deduction to be drawn from these 

 investigations is that the quality of a permanent pas- 

 ture is only in a minor degree determined by the 

 relative abundance of its constituent plants, or, in 

 the words of Hall and Russell, "We can only con- 

 clude that the feeding value of a pasture is largely 

 independent of the floral type." Factors of much 

 greater weight are depth and physical character of 

 the soil, soil moisture and temperature, density of the 

 herbage, and the natural or induced composition of 

 the soil as regards plant-food, and especially in 

 respect of phosphoric acid. 



It seems that the lesson that may be learned from 

 a study of the old pastures of England is that we 

 need not include in a seeds mixture for permanent 

 purposes plants which never bulk to any considerable 

 extent in old grass-land, but that we should include 

 all those which are usually naturally abundant. 

 Take, as an illustration, the' case of perennial rye- 

 grass. In the eighties of last century, when much 

 interest was taken in the subject of the best way to 

 lay down land to grass, an almost violent controversy 

 arose over the desirability or otherwise of including 

 perennial ryegrass in a seeds mixture for permanent 

 pasture. The main opponents of ryegrass were 

 Faunce de Laune and Carruthers, who would have 

 excluded this species in all circumstances. It is 

 a common experience of those who have laid land 

 away to grass with ordinary commercial seed that 

 perennial ryegrass does not persist, but neither, for 

 the matter of that, does white clover. And the 

 probability is that the cause in both cases is to be 

 found in the same direction. Both these plants, as 

 usually grown in thisi and other countries for seed, 

 are the progenv of a long line of cultivated ancestors, 

 grown under somewhat forcing conditions which may 

 be said to undermine the "constitution." They have 

 adapted themselves to their artificial environment, 

 and such adaptation has taken the form of earlv' 

 maturity and the production of a large yield of 

 "bold" seed which is easily marketed. Gilchrist has, 

 of late years, directed attention to the merits of wild 

 white clover, which, as regards persistency is on an 

 altogether different plane from the cultivated or Dutch 

 white. The price that farmers are willing to pav tor 

 the seed of wild white clover is the best proof of the 

 sharp distinction which thev draw between the two 

 varieties. What we now want is similar work on 

 brasses, and particularly on perennial ryegrass, and 

 ft is satisfactory to know that such work has actually 

 been started. 



