January 5, 1922] 



NATURE^ 



25 



Agriculture at the 



AS was to be expected in an important agricultural 

 district such as Edinburgh, the meetings of the 

 Agricultural Section created a good deal ot mterest, 

 and were well attended throughout the whole of the 

 meeting. 



One or two departures from the usual routine have 

 to be noted. Dr. E. J. Russell, of Rothamsted, de- 

 livered a popular address to farmers on "Science and 

 Crop Production " on the day before the formal work 

 of the section began. There was a large attendance 

 from the district, including many representative 

 farmers, and the address was much appreciated. A 

 report of Dr. Russell's address has already appeared 

 in Nature of September 22, p. 116. The second 

 change was that the presidential address, instead of 

 being read at the opening meeting, was circulated 

 amongst the members. At the meeting on Monday, 

 September 12, the president, Mr. C. S. Orwin, gave 

 an abstract of his address, which was followed by a 

 most useful discussion. 



The number of papers offered to the committee was 

 almost embarrassingly large ; they were grouped, so 

 far as possible, according to subject. On the opening 

 day they dealt mostly with soil problems. Dr. Wini- 

 fred E. Brenchley spoke on "The Effect of Long- 

 continued Manuring of Grassland," and described the 

 results of experiments which had been carried out at 

 Rothamsted on permanent meadow-land for a period 

 of sixty-six years — long enough to allow a true esti- 

 mate to be made of the effect of the different fertilisers 

 apart from the influences of season. The efTects of 

 complete manuring, one-sided manuring, no manure, 

 and of lime were considered in detail. Dr. W. G. 

 Smith discussed "Methods of Grassland Analyses," 

 and described the results obtained from plots laid 

 down with various grass mixtures in 19 14. The plots 

 were analysed annually, and figures were given show- 

 ing the composition of the plots now as compared 

 with what was laid down. 



Dr. W. G. Smith and Dr. A. Lauder gave the 

 results of a soil survey which had been carried out 

 in the Lothians. More than 100 square miles have 

 been surveyed and the vegetation recorded on 6-in. 

 survey maps. Definite relations have been estab- 

 lished between the types of vegetation and the pro- 

 ductivity of the holdings, and simple methods of im- 

 proving the grass were described. Dr. Lauder directed 

 attention to the relation between the amount of 

 organic matter and the lime requirement of the soil — 

 a connection which had been noticed by other workers. 

 Mr. M. M. Monie gave an account of a photographic 

 survey of soils which he had carried out in the west 

 of Scotland. His paper was illustrated with an excel- 

 lent series of lantern-slides, and the method he pro- 

 poses, while of limited use by itself, should have a 

 useful place in soil-survey work. 



Prof. Hendrick dealt with "The Absorption and 

 Retention of Manurial Substances by Granitic Soils." 

 These soils are free from carbonate of lime, have a 

 slightly acid reaction, and a high lime requirement. 

 Notwithstanding these conditions, it was found that, 

 even in very heavy dressings, ammonia was almost 

 completely fixed and an equivalent quantity of nitrates 

 recovered in the drainage. The phosphate was also 

 completely retained. The potash was less firmly held, 

 and in the later periods of the experiment the reten- 

 tion was very slight. 



Mr. H. J. Page and Mr. H. G. Thornton con- 

 tributed an important paper on "The Rapid Fluctua- 

 tions in Bacterial Numbers and Nitrate Content of 

 Field Soil and their Interrelation." 



On Friday the papers dealt largely with dairying 

 NO. 2723, VOL. 109] 



British Association. 



problems. Prof. R. A. Berry dealt with the important 

 commercial question of "The Production and Utilisa- 

 tion of Whey." He showed that on a moderate esti- 

 mate the amount of whey produced annually is worth 

 337,oooi. He emphasised the great loss involved 

 under the present methods of disposal, where large 

 quantities are allowed to run to waste, and discussed 

 the possibility of new methods of utilisation. In addi- 

 tion to pig-feeding, the possibility of preparing milk- 

 sugar and whey powders was considered. 



Prof, R. H. Leitch described the recent work he 

 had carried out with starters in cheese-making, as 

 well, as experiments in the manufacture of rennet, 

 methods of standardising rennet extracts, and some 

 new developments in butter-making. Dr. W. Taylor 

 and Mr. A. D. Husband contributed a note on "The 

 Varying Rates of Secretion of Milk on its Percentage 

 Composition." They come to the conclusion that the 

 interrelationship of volume and composition may be 

 summarised thus : — The percentages of protein, fat, 

 and ash vary inversely, and the percentage of lactose 

 varies directly as the daily volume of milk secreted. 

 Two papers were contributed by Dr. Tocher, one 

 dealing with "The Statistical Analyses of Scottish 

 Milk Records," and another dealing with "The 

 Methods of Determining the Significant Differences 

 of Yield of Milk." 



Prof. Hendrick described "A New Scheme for the 

 Determination of Unexhausted Manurial Values," and 

 dealt in particular with the question of cumulative 

 fertility. Dr. Tocher gave the results of experiments 

 on "The Citric Solubility of Manurial Phosphates," 

 and concludes that citric solubility Is a worthless test 

 from the agricultural point of view. The only prac- 

 tical tests are :— (i) The total phosphatic content, 

 (2) the degree of fineness of grinding, and (3) freedom 

 from substances of an injurious character to plants. 



Mr. J. Alan Murray described some recent experi- 

 mental work which he had carried out on "The Com- 

 position of Ensilage." Mr. Murray dealt with the 

 loss involved in the making of ensilage, and considered 

 that it was a fallacy that farmers can save money by 

 dispensing with root crops and substituting ensilage in 

 the rations of farm animals. He considered that it was 

 not possible to reduce the allowance of concentrated 

 food by substituting ensilage for roots. In the discus- 

 sion which followed some exception was taken to Mr. 

 Murray's estimates as to the cost of producing ensilage. 



The meeting on Monday was devoted to economic 

 questions, and began with the discussion on the presi- 

 dent's address, to which reference has already been 

 made. Lord Bledlsloe followed with a paper on 

 "Wheat as the Basis of Britain's Food-Supply in 

 Time of War." He pointed out the advantages of 

 potatoes, supplemented by pig-meat, over wheat. 

 Great Britain is self-contained in its potato require- 

 ments and an exporter, while under normal conditions 

 she imports four-fifths of her wheat requirements from 

 abroad. The normal production of wheat Is pre- 

 ponderantly in the eastern counties of Great Britain 

 (ten counties out of eighty-six provide more than half 

 the total output), while potatoes are grown in every 

 part of the kingdom. Many farmers are wholly un- 

 familiar with wheat production, and have neither the 

 implements nor the buildings necessary for its produc- 

 tion and storage, but every farmer, gardener, and 

 allotment-holder knows how to grow potatoes. Then 

 again, the wheat crop may be wholly lost for human 

 requirements through bad weather or incendiarism. 

 Potatoes, though subject to disease (which can be mini- 

 mised bv spraving), are less vulnerable, as the edible 

 tuber is beneath the ground. Potatoes provide an 



