FIELD EXPERIMENTS ON MANUBE CONSTITUENTS. 167 



The soil of this field is considered a good barley soil. It is full of lime- 

 stone, gravel, and fragments of oolitic stones of larger size, and, like most 

 soils in the neighbourhood of Cirencester, contains much clay. On analysis 

 it gave — 



Manure 10-254 



Organic matter and matter of combination 6*947 



Oxides of iron and alumina 12"754 



Phosphoric acid -659 



Carbonate of lime 18'64'0 



Sulphate of lime -397 



Magnesia -195 



Potash -967 



Soda -309 



Silica (soluble in dilute caustic potash) I^'OIS 



Insoluble siliceous matter and loss (chiefly clay) Si'SGi 



100-000 

 The following tabular statement embodies the yield in grain and straw 

 which the several plots furnished. 



Produce of Corn and Straw. — Experiments ivith top-dressings on Barley. 



Grain. Straw. 



f ^ -^ 



At 56 lbs. per bushel. 



No. 1 . Mixed mineral and ammoniacal 1 ibs. bush. lbs. cwt. qrs. ib». 



manure, 4 cwt. per acre ; 1 2524 45 4 22 2 16 



cost£l 125. j 



No. 2. Peruvian guano, 2| cwt. per acre; 1 24,32 43 24 21 2 8 



cost £1 125. ad. J 



No. 3. Nitrate of soda, I5 cwt. perl 2753 49 14 24 3 



acre; cost £1 IO5. per acre, j 

 No. 4. Nitrate of soda l\ cwt., and 1 



3 cwt. of common salt; cost I 2706 48 18 23 3 16 



£1 135. J 



No. 5. 3 cwt. of salt per acre ; cost 35. 2308 41 12 16 2 



No. 6. Nothing 2174 38 46 12 2 12 



No. 7. Sulphate of ammonia, 2 cwt. I 2642 47 10 22 22 



per acre; cost £1 I65. j 



No. 8. Soot, 32 bushels per acre; cost") 2688 44 4 20 2 26 



165. j 



These barley experiments, on the whole, gave results corresponding to the 

 results obtained in the wheat experiments. Thus, the plots dressed with 

 nitrate of soda gave the largest increase, and sulphate of ammonia used alone 

 gave a larger increase than the mixed mineral and ammoniacal manure. 



The results do not, it is true, exactly agree in all particulars ; but perfect 

 agreement cannot be expected in field-experiments. 



Thus, in the barley experiments, guano appears to have produced a less 

 favouraljle result than in the wheat experiments, whilst the mixed mineral 

 and ammoniacal manure appeared to be better adapted for barley than for 

 wheat. 



"Whether this was the case, or whether the apparent differences in the 

 effects of the same dressings on barley and wheat were due to differences in 

 the composition and condition of the soil of the experimental fields, I am 

 unable to decide. - 



