26 



ON EXPERIMENTS WITH GL'ANO, 



[Appendix, 



The quantity here indicated may be intimately mixed with 100 lbs. of chalk, 

 and will be fully equal in efficacy, I believe, to 4 cwt. of guano, now selling 

 at £5. 



At the same time it is desirable that the i-elative efficacy both of this mixture 

 (artificial guano), and of the American guano, should be tried by actual experi- 

 ment in comparison with other substances of known value, and which are 

 supposed to act in a way somewhat similar. 'I'hs substances with which I 

 would suggest that such comparative experiments should, in the first place, be 

 made, are farm-yard manure, bone dust, and rape dust, and the following 

 scheme exhibits the proportions in which they may be added to the different 

 plots of land on which the experiments are intended to be made : — 



The practical farmer need not be deterred by the formidable array of experi- 

 ments above suggested. He may try any two or three of them, and his results 

 will be valuable in proportion to the accuracy with which his land is measured 

 and his manures and crops weighed. I have taken 20 tons of farm-yard manure 

 as a standard, though in many highly farmed parts of the country lio more than 

 15 tons are usually applied. Twenty bushels of bones are recommended by the 

 Doncaster report, and I have lately found that in the Lothians 1 cwt. of rape 

 dust is considered to replace 1 ton of farm-yard manure. This proportion of 

 course will vary with the c[uality of the latter manure ; but whatever quantity 

 of this latter we take as the standard of comparison, it is easy to adjust the 

 proportions of the other substances accordingly. I have not recommended any 

 trial -to be made with more than G cwt. of guano, because, where farm-yard 

 manure is valued only at 6s. or 7s. per ton, 5 cwt. of the former would cost as 

 much as 20 tons of the latter. '^ 



The above experiments are intended to be made with the green crop, and to 

 be continued during an entire rotation :t any pair of them, however, may be 

 tried on single crops, whether of corn or of turnips and potatoes. In this way 

 guano ought also to be tried against nitrate of soda and against bones, upon 

 seeds and upon old grass-lands. The mode in which such experiments may 

 be made will speedily suggest themselves to the intelligent farmer. J71 all 

 cases the results should be accurately recorded, and, if possible, published. 



' When this paragraph was written, the price of guano was 25s. a cwt. : it is now (May, 

 1842> reduced to 15s. ) . & , v 7, 



t By this I mean that the effect of these several manures, applied once for all to the green 

 op at the commencement of the rotation, should be traced on each successive cron throuffh 



crop 



the entire course of cropping. 



the rotation, should be traced on each successive crop through 



