i 3 6 SCIENCE PROGRESS 



lime. The importance of such an accumulation of humus in 

 modifying soil texture need not be enlarged upon. 



In view of these and many other important factors, certain 

 questions at once arise. For example, does mechanical analysis, 

 which has given such valuable results in the study of arable 

 soils, afford equally useful indications in the case of pasture 

 soils ? Is chemical analysis a useful guide ? If so, can the 

 large number of data obtained from arable soils be taken as 

 standards ? And, to put the whole matter as briefly as possible, 

 how far, in considering pasture soils, must we modify our ideas 

 of the relative importance of the various factors which con- 

 stitute what may be termed the fertility of the soil ? 



Such are shortly some of the more general questions. In 

 addition, a large number of local problems of considerable 

 complexity arise in connexion with pasture land and, as has 

 often happened in like cases, the detailed investigation of some 

 of these has served to throw light on the larger problems. 



Pasture Soil Analyses. — The value of soil analysis as a guide 

 to the manurial treatment of poor pastures has been dealt with 

 by Wood and Berry l of the Cambridge University School of 

 Agriculture, in connexion with a series of experiments on 

 methods of improving poor grazing land ; the agricultural 

 results have been discussed by Middleton. 2 The soils from 

 a number of centres at which the experiments were carried out 

 were examined, in order to ascertain whether the results of the 

 soil analyses could be correlated with the results of the various 

 methods of treatment. Of the latter, the most important was 

 the remarkable improvement effected in almost all cases by the 

 use of basic slag ; but determinations of the total phosphate 

 present in the soils gave no indication of deficiency in phosphoric 

 acid. On the other hand, the figure for " available " phosphates 

 {i.e. soluble in i per cent, citric acid) was of greater value and 

 appeared to be a trustworthy guide as to which soils might be 

 expected to respond to phosphatic manuring, " if for pasture 

 soils the limit below which 'available' phosphate may be 

 considered deficient is fixed as high as o - o2 per cent." 



Other results indicated that the figures for total nitrogen, 

 total potash and lime were not of much help in determining the 

 best methods of manuring ; but if the soil contain not more 



1 Jour. Agric. Science^ vol. i. p. 114. 



2 Ibid. vol. i. p. 123, 



