256 



GUANO. 



farm-yard manure gave straw and corn in the propor- 

 tion of 1*2; guano, in the proportion of 1*3. As 

 regards the power of the soluble guano constituents to 

 pass through the soil, we find from these experiments 

 the same conditions existing as with those of farm-yard 

 manure. At Cunnersdorf and Kotitz the whole guano 

 constituents hardly produced any effect upon the clover 

 crop ; whilst at Mausegast and Oberbobritzsch a per- 

 ceptible increase was the result. 



Silicic acid, which gives strength and firmness to 

 stalks and leaves, is not one of the ingredients of guano ; 

 hence, after manuring with guano, the tendency of the 

 cereals to lodge, so much dreaded by agriculturists, is 

 observed on many fields poor in silicic acid, whilst on 

 others abounding in this substance it does not occur. 

 On many soils mis tendency may be cured by dressing 

 with lime before applying the guano ; and in other 

 cases it may be lessened "by mixing dung made from 

 straw with the guano. 



If we calculate the increase in the produce of 

 cereals, potatoes, and clover, obtained severally in the 

 years 1851 to 1854, from 100 Ibs, of guano we find 



100 Ibs. of guano gave increase of produce. 



These results show that the same quantity of guano 

 has an equally dissimilar effect upon different fields as 

 farm-yard manure, and that it is quite impossible to 

 draw from the crops obtained any inference as to the 

 quality or quantity of the manuring agent employed to 

 produce them. The field at Mausegast had received 



