Field Experiments of the Fast Year by f}ie Chemical Branch. 305 



increased yifld tlie superpliuspliate shows a slight advantage over 

 Thomas phosphate, and both of these a marked superiority over 

 bonedust, using e(pial quantities of average samples of these manures 

 found on the market. For 2 cv^ts. to the acre of each have produced 

 increases of 1473, 1332, and 1056 lbs. respectively. The figures 

 below will reveal to what extent the increased yields of each group 

 support the results of the general average. 



Increased yields resulting from : — 



In all cases, with the exce})tiou of the Mornington group, the 

 returns from bonedust fall considerably behind those fi'om either 

 superphosphate or Thomas phosphate. In two cases out of the 

 five, Thomas ])hosphate gives heavier yields than supeirphosphate, but 

 in the remaining three the su])er[)hosphate shows to advantage. One 

 fact seems clear; that is, that Thomas phosphate as a supplier of 

 phosphoric acid compares much more favourably with superphosphate 

 oil southern soils than in the North, and experiments so far incline 

 me to think that on the lighter soils of a sandy nature, as well as on 

 peaty lands, Thomas phosphate of a standard equal to that used in 

 the experiment may be finally found to claim priority over a super- 

 phosphate of a similar composition to the one employed. The 

 numerous experiments of the present year ought to throw light on 

 this question. The analysis of the Thomas phosphate used showed 

 14'79 per cent, citrate soluble phosphoric acid, and 2*37 per cent, 

 insoluble ; the superphosphate, 17 '63 per cent, water soluble, and 

 1'55 ])ev cent, citrate soluble. 



Thk Quantity of Manure to Aim'i.y. 



And now a few words on the (pumtity of manure to apply. It is 

 just here w!;ere both caution and tact are required. Caution in not 

 advocating an expenditure which might frighten the farmer away 

 from the subject, and tact in advancing views which may differ 

 considerably from his ideas. The farmer must be left to himself to 

 decide what quantity of manure he will use. I shall not attempt to 

 influence him. My duty ends in showing up to what quantities 

 increased yields at a profit might be obtained. These quantities are 

 much larger than the average farmer will for some time feel disposed 

 probably to apply. To turn to the average returns again, it will be 

 found that 1 cwt. of su])erphosphate has shown an increase of a little 

 more than one-half a ton of hay to the acre ; 2 cwt., an increase of 

 1473 lbs., and 3 cwt., an increase of over 17 cwt. That is, that the 

 additional 2 cwt. of manure, costing 9s. 6d., has j)roduced approxi- 

 mately 7 cwt. of hay more than the 1 cwt. The value of this 7 cwt. 



