6 Experiments with different Top-dressings upon Wheat. 



These quantities of the different fertilizers were obtained in each 

 case at an expense of II. 12s. Qd. per acre, except the larger dose 

 of wheat-manure on Plot V., the cost of which was 2/. 8s. 

 per acre. In this estimation the actual prices paid were taken. 

 Peruvian guano, at the time of application, was 131. per ton ; 

 nitrate of soda, 18/. 10s. per ton ; common salt, II. 10s. per ton ; 

 wheat-manure, 8/. per ton. 



The price of the chalk-marl could not be accurately ascer- 

 tained, and probably 8s. per ton will be rather under than above 

 the price at which it was procured. The manures were all finely 

 sifted (except the chalk-marl), mixed with about 10 times their 

 weight of fine soil, and sown broadcast on the afternoon of the 

 22nd of March, 1859. 



The land was clean, in good condition, and moist. A portion 

 of the soil from the experimental field was submitted to a me- 

 chanical and to a chemical analysis. It yielded the following 

 results : 



Composition of Experimental Wheat-Field ; Field No. 2 of the 

 Royal Agricultural College Farm, Cirencester. 



a. Mechanical Analysis. 



Moisture 4'18 



Organic matter and water of combination .. 9' 75 



Lime 18'63 



Clay 61-76 



Sand 5-68 



100-00 



It will be seen that there is but little sand or silica, that can 

 be separated by washing, in this soil. Notwithstanding, the 

 straw of the wheat was very stiff. 



b. Chemical Analysis. 



Moisture 4-18 



* Organic matter and water of combination .. 9*75 



Oxides of iron and alumina 16-25 



Phosphoric acid *12 



Sulphate of lime '31 



(Containing sulphuric acid) (*18) 



Carbonate of lime 18*63 



Magnesia .. .. '18 



Potash -41 



Soda -11 



Insoluble silicates and sand (chiefly clay) . . 50' 45 



100-39 



*Containing nitrogen - . . . 37 



Equal to ammonia 45 



In the preceding analysis the phosphoric acid was determined 

 by the molybdate of ammonia process, which furnishes exceed- 



