372 TRANSACTIONS OP SECTION M. 



fectly reliable. Involving as they do considerable outlay on fencing, water, 

 weighing machines, etc., and necessitating the use of large areas of uniform land, 

 such experiments were not likely to be undertaken with great frequency, but I 

 have been able to find reports of nine in England, ^^ twelve in Scotland,^^ two 

 in Ireland,^* and one in New Zealand.-^ Two of them are situated at Cockle 

 Park, of which the original in Tree Field has now completed its twenty-third 

 season, while the other in Hanging Leaves has a record of sixteen years. 



I propose now to make a brief general survey of the more salient results of 

 this work. 



The outstanding feature of these experunents is the great and profitable 

 effect of phosphates. In this material the farmer is placed in possession of an 

 agent of production whose effects on the output of meat, milk, and work from 

 the pastures of this country are only limited by the supplies. In many cases 

 the increase of meat is trebled and even quadrupled, with a return on the 

 original outlay that runs into hundreds per cent. As between the various 

 sources of phosphate there is unmistakable evidence that basic slag is the most 

 effective, not only in respect of aggregate yield of meat, but also, and more 

 particularly, when the net financial return is considered. This conclusion is 

 also reached by Carruthers and Voelcker in a long series of pasture experiments 

 carried out in 1896-9 for the Royal Agricultural Society of England. ^'^ In these 

 experiments, however, the effects were only estimated by occular inspection. 

 The primary effect of phosphates is due to the marked stimulus that they give to 

 the growth of clovers and other Leguminosae, and as these plants revel in a 

 non-acid soil the alkaline character of basic slag appears exactly to suit their 

 requirements. It seems highly desirable that a ' manuring for meat ' experi- 

 ment should be conducted with raw phosphates, whose effects on pasture seem 

 distinctly hopeful. Gilchrist dressed a pasture in Northumberland with equal 

 quantities of phosphoric acid derived respectively from basic slag, Belgian and 

 Algerian phosphate, and two and a half years later he reported from occular 

 observation ' that when such mineral phosphates are as finely ground as basic 

 slag the phosphates they contain may be equally effective." It must be said, 

 however, that this opinion is hardly borne out by the quantitative results 

 obtained on an adjoining meadow where the weight of hay produced by basic 

 slag was distinctly greater than that grown on the plots dressed with the other 

 two phosphates.-^ 



In regard to the quantity of phosphatic manure that can most effectively be 

 employed per acre, it would appear that in the case of inferior pasture a heavy 

 initial dressing, .say 200 lb. of phosphoric acid or more per acre, is likely to be 

 nearly twice as effective as half this dressing, and therefore actually much more 

 profitable. To secure the best results the Leguminosae must be rapidly brought 

 up to their maximum vigour, so that they may fully occupy the ground before 

 the grasses have had time to react to the effects of the accumulated nitrogen. 



One of the most striking results of these pasture experiments is the long 

 period over which the action of phosphates persists. Even at the end of nine 

 years the meat-producing power of half a ton per acre of basic slag is far from 

 being exhausted. It is not suggested that this persistent action of slag — and no 

 doubt this applies also to any other effective phosphate — is due to unappro- 

 priated residues. It is much more probably due to two other causes ; {a) to the 

 fact that on a pasture in contrast to a meadow manurial elements are kept in 



'' ' Guide to Experiments at Cockle Park for 1918 ' (Bulletin No. 27). 

 Jour. Bath and West Soc. 1910. Cambridge Guide to Experiments, 1907. 

 Supplement No. 5 to Jour. Board of Agric, 1911. Wakerley, 'Manuring for 

 Milk ' ; Midland Agricultural and Dairy Institute, 1912. 



" 7'rans. High, and Agric. Soc. 1905 and 1908. Wright, 6th and 10th Reports 

 on Experiments, West of Scot. Agric. Coll. 1905 and 1911. Greig, Bulletin 

 No. 16 of Aberdeen and North of Scot. Coll. of Agric. 



2* Journal of the Department of Agric. for Ireland, September 1919. 



-^ New Zealand Journal of Agriculture, 1919, p. 15. 



" Carruthers and Voelcker, 2nd Report on the Grass Experiments con- 

 ducted by the Society, Jour. Roy. Agric. Soc. 1900, p. 116. 



'" Gilchrist, Jour. Newcastle Farmers' Club, 1917. 



