374 TRANSACTIONS OF SECTION M. 



in three dressings in nine years. A noticeable effect was produced at all 

 stations, and at two of them the gain was a profitable one. The effects of lime 

 can be followed for twenty-one years at Cockle Park, where the soil naturally 

 contains 0-59 per cent, of calcium carbonate. During that period an aggregate 

 of five and a half tons per acre was applied in seven dressings, the phosphate 

 to which it was added being superphosphate in the first nine years and basic 

 slag in the next twelve. The area receiving the lime was the same throughout. 

 The action of the lime has proved to be a progressively decreasing one. On the 

 average it produced an annual increase of 22 lb. live weight in the first nine 

 years, and of 8 lb. in the next six years, whereas in the concluding six years 

 of the period it has actually caused a reduction in live weight of 8 lb. per acre 

 per annum. From these figures it would seem that lime has had more effect 

 when used with superphosphate than when basic slag was employed. But 

 already at the end of the ninth year, up to which time superphosphate was 

 alone employed, the effects of lime were noticed to be declining at all the 

 stations, a fact to which I called attention in reporting in 1911 on the influence 

 on the production of mutton of manures applied to pasture,^' where it is stated 

 ' that in the penultimate and last years [of the first nine] the beneficial action 

 of lime seems to be on the wane,' and where the opinion is expressed ' that 

 the lime is acting rather as a liberator of inert nitrogen than as a direct plant 

 food.' It would appear that this conclusion is confirmed by the experiences 

 of later years. It would seem therefore that Wood and Berry's suggestion in 

 the case of poor pastures is justified — namely, that ' the limit for calcium 

 carbonate below which liming may be expected to be profitable is probably below 

 0-25 per cent.' ^' 



The action of lime on grass land is a. large subject, too large, in fact, to be 

 exhaustively pursued here. But I may call attention to a series of experiments 

 which I started on meadow land in Cumberland in 1895, and which have been 

 reported on on several occasions. '* At certain stations the use of 500 lb. per 

 acre of caustic lime five times in eight years as an addition to a ' complete ' 

 manure has markedly decreased the hay crop, and it would appear that this 

 dressing has exceeded the necessities of these soils in respect of ' lime require- 

 ment ' in the sense of the term as employed by Hutchinson and Maclellan,^' and 

 that the stage of ' partial sterilisation ' has been reached. Against the validity 

 of this suggestion, however, there is the fact that the depressing influence of 

 the lime was manifest in the first year. While there is evidence that lime as 

 an agent in the improvement of pasture is a substance to be used with caution, 

 it would appear that where there is a large accumulation of sour humus it is 

 only through the use of lime that this can be got rid of, and the way thereby 

 prepared for furtlier improvement by the use of phosphates. 



The addition to sujjerphosphate of moderate dressings of nitrogen in the 

 form of sulphate of ammonia or of nitrate of soda was tried at the three main 

 manuring-for-mutton stations, and at two others. There is no need to go into 

 a detailed discussion of the results. The evidence is overwhelmingly against 

 the use of nitrogen on pastures. It undoubtedly stimulates the vigour of the 

 non-leguminous herbage, but tWs reacts on the growth of the clovers, with the 

 result that the production of meat is sometimes, as at Cockle Park, actually 

 and substantially reduced. 



At the three original stations dissolved bones were also tried, the comparison 

 being with equal quantities (200 lb. per acre in nine years) of phosphoric acid 

 derived respectively from basic slag and superphosphate. The dissolved bones 

 supplied in addition from about 30 to 40 lb. of organic nitrogen. All manures 

 were applied as to half of the first year, and, as to the other half, at the com- 

 mencement of the fourth season, the experiment being continued for nine years 



2^ Supplement No. 5 of the Jour. Board of Agric, p. 50. 



" Op. cit., p. 117. 



^8 Somerville, Eiqhth Annual Report on Experiments, in the Counties of 

 Cumberland, Durham and Northumberland, p. 28. T. H. Middleton, Tenth 

 Annual Report, p. 87. D. A. Gilchrist, Eleventh Report, p. 26. 



^' H. B. Hutchinson and K. Maclellan, Jour. Agric. Science, vol. vi., p. 302, 

 and ibid., vol. vii., p 73. 



