1002 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



investigation, to keep our choice of concentrated fertilisers as simple as 

 possible. Thus, we have restricted our choice of phosphates to super- 

 phosphate and basic slag ; but this is not due to any kind of conviction 

 that these are under all circumstances to be preferred to other forms of 

 phosphatic fertilisers. On the contrary, we believe that, in this kind of 

 farming, guano and bone meal find a specially appropriate place. 



Speaking generally of the choice of phosphates, it may be probably 

 laid down as a good rule that, on soils containing sufficient carbonate of 

 lime to effervesce when mixed with dilute mineral acid, the best form of 

 phosphates to use is either superphosphate or some similar form of acid 

 manure, such as dissolved guano or dissolved bones. On soils, however, 

 which are deficient in carbonate of lime, it will be better to use either 

 basic slag, raw Peruvian guano, or bone meal ; or a mixture of bone meal 

 and superphosphate ; or the material lately introduced into the market, 

 on the suggestion of Mr. John Hughes, under the name of " basic super- 

 phosphate," which consists of superphosphate neutralised with lime; or, 

 at any rate, that one or other of these manures be applied alternately 

 with superphosphate. 



Similarly, it has been impracticable, as well as beyond the direct 

 scope of oar inquiry, to compare the relative efficacy of nitrate of soda 

 with that of other concentrated nitrogenous fertilisers, such as sulphate 

 of ammonia or Peruvian guano, or with that of less rapid but, when 

 properly used, efficacious organic manures like fish guano, rape meal, &c. 

 When it is explained that our scheme of experiments already involves 

 over three hundred separate plots or sub-plots, the produce of each of 

 which has to be gathered and weighed separately, the impossibility of 

 undertaking comparative trials between nearly allied fertilisers will be 

 apparent. Probably many of the results that we have obtained by the 

 use of nitrate of soda and superphosphate or basic slag might have 

 been equally well obtained, on some soils, by the use of sulphate of 

 ammonia, rape dust, or fish guano with bone meal or dissolved bones ; or 

 by the use of Peruvian guano, raw or dissolved ; each of such manures, 

 of course, being applied in the fashion best suited to its special rate of 

 activity. The results that we are obtaining, however, with the simple 

 materials nitrate of soda, phosphates, and potash salts, will, we hope, 

 show eventually how far we may go in the liberal nitrogenous feeding of 

 vegetable and fruit crops ; and we hope that those who are disposed to 

 make comparative trials between the concentrated fertilisers used by our- 

 seh es and other fertilisers which have been enumerated, will find that 

 our work has served to indicate to them the most probable lines of 

 successful experiment. 



Our scheme of experiments, it will have been gathered, enables us to 

 contrast the effects of light and heavy dunging continuously practised 

 year after year, and also to compare or contrast light and heavy dunging, 

 respectively, with light dunging supplemented by the use, in different 

 quantities, of concentrated chemical fertilisers ; and also with the effects 

 of the latter when unaccompanied by dung. 



