Experiments upon Sivedes. 17 



fore merely pushes on the young plant, and is no longer avail- 

 able when the roots begin to swell. The fact is, no soluble 

 phosphate i. e. bi-phosphate of lime, as such, can enter into 

 the delicate structure of the root-fibres ; it must first become 

 insoluble before it can benefit the young turnip-plant, and this 

 it does readily when it is washed by a shower of rain into the 

 soil, or applied at once in a state of solution with the liquid- 

 manure drill. At any rate we have here presented to us an 

 instance in which a superphosphate containing no nitrogen, and, 

 practically speaking, no insoluble phosphates, produced an 

 increase of 6 tons of cleaned swedes, topped and tailed, or almost 

 as large an increase as any of the fertilizers tried, in these expe- 

 riments. 



Plot 18. Manured with 3 cwts. of Dissolved Bone-ash and 1 cwt. of 

 Sulphate of Ammonia. 



tons. cwts. qrs. Ibs. 



Produce .. .. > OJ h& 20 6 3 24 

 Increase 5 12 2 20 



In this experiment the addition of sulphate of ammonia to 

 dissolved bone-ash appears to have done no good whatever. I 

 do not think, however, that the small difference in weight 

 between Plots 17 and 18 warrants the conclusion that its influ- 

 ence was prejudicial. 



Plot 19. Manured with 3 cwts. of Sulphate of Potash. 



tons. cwts. qrs. Ibs. 



Produce 17 24 



Increase 2610 



The sulphate of potash used in this experiment was a good 

 commercial sulphate. It produced about the same increase as 

 2 cwts. of sulphate of ammonia; and, in comparison to the effect 

 which phosphatic manures produced, must be considered as a 

 manuring constituent which did not seem to be required on the 

 soils on which the experiments were tried. 



Plot 20. Manured with 3 cwts. of Dissolved Bone-ash and 1 cwt. of 

 Nitrate of Soda. 



tons. cwts. qrs. Ibs. 



Produce 21 24 



Increase 66 01 



In comparison with the produce from No. 17, we have here in 

 round numbers 14 cwts. more roots. This larger increase 

 falls quite within the limits of variation which we must natu- 

 rally expect in two different parts of the same field. It cannot 

 be, therefore, regarded as a proof that nitrate of soda increased 

 the efficacy of the dissolved bone-ash. 



Rejecting some anomalous results, as those obtained from 



