CH. XlJ 



Fish Gua7io 



193 



Table XIV. Effect of Peruvian guano on yield of crops. 

 Rothamsted, Little Hoosfield. Total iwoduce per acre 

 {unmanured =100) 



Manufactured manures. Fish guano. Eish guano or 

 fish meal is obtained from fish which for any reason 

 cannot be sold as food. The oil is first extracted by- 

 heat and pressure and the residue is then finely ground. 

 It usually contains about 8 to 10 per cent, of nitrogen, 

 about 1 per cent, of K2O, and 4|^ to 9 per cent, of PgOg, 

 equivalent to 10 to 20 per cent, of tricalcic phosphate^; 

 sometimes, however, more bone is present. It is a verV 

 useful manure for hops and in gardens, and has given 

 good results when applied at the rate of 4 lbs. per rod 



^ A large number of samples from the North Shields district analysed 

 by Collins had the following mean composition: 



N 8-00-2 %; P2O5 5-90-8 %; K^O M0-3 %. 

 R. s. 13 



