220 CHEMICAL DEPARTMENT. 



which, as has been shown, favoured the production of well- 

 ripened heavy grain. 



A general view of the produce of 1887 upon land unmanured 

 for two years shows, despite the drought — 



1. That a very considerable quantity of the light manures 

 applied in former years still exists in the soil after two crops 

 have been removed. 



2. That, as regards phosphatic manures, the most effective 

 residue is left in those plots to which soluble phosphates were 

 applied. 



3. That the most effective residue is found in the plot to 

 which dissolved bones was applied. 



4. That, as regards nitrogenous manures, the residue left by 

 sulphate of ammonia is greater than that left by nitrate of soda. 



5. That the insoluble nitrogenous inanures have left a larger 

 residue than the soluble ones. 



6. That dried blood has left a more effective residue for the 

 barley crop than other nitrogenous manures. 



7. That, as regards potash manures, the sulphate has left a 

 larger residue than the chloride. 



8. That the exclusive use of nitrate of soda reduces the soil 

 to a low state of fertility, from which it does not easily recover. 



9. That the exclusive use of potash manures still more rapidly 

 injures the fertility of the soil, but that, with the discontinuance 

 of the manure, the soil recovers somewhat rapidly. 



10. That by the application of light manures heavy crops can 

 be grown, but that, in order to secure the continuance of high 

 fertility, they must be applied annualh^, of a kind and quantity 

 appropriate to the crop. 



HARELAW BARLEY CROP, 1887. 



In 1886 a crop of potatoes was grown on Harelaw station, 

 and in order to observe the effects of various manures upon the 

 crop, and at the same time to obtain some information on the 

 subject of unexhausted fertility, each plot was cut in two, and 

 manures applied to the one half, while the other was left 

 unmanured. The results are reported in last year's Tronsac- 

 tions, where a summary of the most noticeable facts is given 

 on pp. 225-6. The crop last year was barley, and the experi- 

 ments were conducted on the same lines ; the unmanured half 

 of each plot was again left unmanured as a basis of comparison, 

 and so that the unexhausted fertility after the removal of two 

 crops might be observed. 



Before proceeding to examine in detail the after effects of 

 the various manures, it is necessary to observe that this station 



