Fii'lil lliperinu-nts uf the Fast Year tnj the Chciaical Branch. 3Uo 



g-roiiiid. hi otlier words, by the a])pliciition <if an jippropriate com- 

 biiiMti(»ii of maiuire, we> liave more tliaii doubled the ])ro(hictive 

 power of the soils experimented on. Now, sncli a fact as this will 

 serve as a very good introduction to flie subject I am dealing- with. 

 It will perhaps clear away a little of tlic prejudice which might still 

 cling to some of you against the use of manures, and it might 

 ])erhaps open np vistas of possibilities in tin- same direction on a 

 class of soils owned by some of yonrselves. The question as to 

 whether these results have been obtained at a good ])rofit— after all 

 the principal consideration — will be gone into later on. As a first 

 investigation, we will inquire how tliey liave been obtained. 



If you look at the head of the tabic yon will see that the plots 

 have been numbered from 1 to 15, and you will also find given there 

 the manures which have been used on each plot. On plots 1, :>, 1, (> 

 and 7 phosphatic manures only have l)een used (I)onedust contains ii 

 litth' nitrogen) ; that is, manures containing phosphoric acid <mly. 

 In the case of northern soils, it is this ingredient only which would 

 be re(iuii*ed. Continuing along the ])lotSj it will be found that on 

 No. 1' a manure containing phosjthoric acid and potash has been 

 given. On ]»lot 12 a manure containitig phosphoric acid and nitrogen, 

 and on ])lot lo a manure containing phosphoric acid, potash and 

 nitrogen. Now, the object of the exptn'iment is to see if we get 

 larger yields where these combinations have been used, and to 

 determine the ])articular combination giving the maximum yield. 

 AVe will first consider the figures of the general average. For 

 comparisons, all returns will be referred to those of plot 'A. On this 

 plot, 2 cwt. ordinary superplios])hate : that is, a manure containing 

 pliosj)lioi-ic acid only has resultcfl in an average increase of •()-") tons 

 of hav to the acre. Providing, now, the soils of the Soutli were 

 similar in chemical comjjosition to those of the North, we shoidd get 

 n(j appreciable increased results, as far as grain is concerned, and 

 probal»ly straw also, frt>m the addition of any other ingredient to this 

 super])hosj)hate. Ihit the soils of the South apparently differ very 

 considerably from those of the North, for on plot 12, where nitrogen 

 in the form of sulphate of ammonia has been added, there is an 

 increase of 1*20 tons shown. In other words, the increase has been 

 ])ractica11y doul)led by the addition of nitrogen. On ])lot 1-) again, 

 wliere potash in the form of potash chloride has been addecl to the 

 mixture used on plot 12, there is a further opei'ative effect shown, for 

 the increased yield of hay in this case is V'11 tons, comjiared with 

 1*20. The conclusion to be drawn, then, is that the three ingredients, 

 ])hos])lioric acid, nitrogen and |»otash have all helped to produce the 

 maximum figure of the average. Potash, to a small extent; pln»s- 

 ])horic acid and nitrogen to a very marked degree. The relatively 

 small effect of potash is further confirmed by the result on plot 9. 

 The increased yield on this plot, where superphos))hate and ))otash 

 chloride have been used, is '87 tons, com])ared with "65 where the 

 su])erphosphate alone has been ap])lied. 



But we have been dealing with the general average of five 

 diffei-ent groups of fields established in as many different centres of 



