494 Summary of Agricultural Experiments, [sept., 



This proved to be the case at three centres with mangolds, and also 

 at two centres with potatoes. For the potato crop on black, peaty 

 soils a dressing of 8 to 10 cwt. of superphosphate per acre is likely to 

 give the greatest profit, while on silty soils from 4 to 6 cwt. of super- 

 phosphate, with \ cwt. sulphate or muriate of potash in addition, will 

 probably give better results. 



Experiments with barley, beans, and hemp on these black soils have 

 also proved superphosphate in large dressings to be the most profitable 

 manure. 



Rotation Experiments (Northumberland C.C., Guide to Expts. at 

 Cockle Park, 1909). This publication gives the results of the third 

 series (1905-1908) of rotation experiments which have been carried out 

 since 1897. The rotation is turnips or swedes, oats or barley, hay, and 

 oats. Twenty-one different systems of manuring have been tested. 

 The average value of the yield of the unmanured plot was ^16 195. 6d. 

 in the first rotation, £15 45. in the second, and ^'13 55. lod. in the 

 third, while the average value of the four crops on the manured 

 plots was £26 is. 3d., ^27 155., and ^29 155. respectively in the three 

 rotations. 



The report itself should be consulted to ascertain the effect of the 

 manuring on the different crops, but it may be said that the plot which 

 has given the highest increase over the unmanured plot, after deducting 

 the cost of the manure, received 10 tons of dung for the root crop and 

 7 cwt. of a complete dressing of artificial manures for the hay crop. 

 This plot (No. 17) has given a gain over the unmanured plot in the 

 12 years of ^35 os. 8d. The next highest (No. 15) has given 

 ^33 9 s - 8(2. for the application of 10 tons of dung alone. Ten tons of 

 dung and 7 cwt. of complete artificials applied to the root crop on 

 Plot 16 gave a smaller nett yield (^"31 35. iod.), while the result was 

 practically the same (^31 165. gd.) on Plot 18, where 10 tons of dung 

 and 3I cwt. of artificials were applied to roots and 3! cwt. artificials to 

 the hay crop. This was also the case on Plot 19 (£31 185. 3d.), where 

 10 tons of dung were given to the hay crop in addition to the dressing 

 for Plot 18. 



The best results, therefore, have been obtained by applying dung 

 only to the swedes and complete artificials to the hay. The standard 

 dressing of artificial manure consisted of 1 cwt. sulphate of ammonia, 

 5 cwt. superphosphate, and 1 cwt. muriate of potash. 



Calcium Cyanamide (Northumberland C.C., Guide to Expts. at 

 Cockle Park, 1909). — Trials were made in 1907 and 1908 with calcium 

 cyanamide on oats, which showed it to be a useful nitrogenous manure. 

 Further trials with oats and mangolds are in progress. 



New Nitrogenous Manures (West of Scotland Agric. College, Bull. 

 No. 40).- — This Bulletin describes the experiments with new nitrogenous 

 manures conducted by Prof. R. A. Berry at the College Expt. Station 

 on oats, hay, mangolds, potatoes, and sugar beet. 



Inoculation Experiments (Harper-Adams Agric. College, Field Ex- 

 periments, 1908). — A series of trials of " Nitro-Bacterine " were carried 

 out, along with another preparation sent by Dr. Hutchinson, of 

 Rothamsted. The results obtained both from the open ground and 

 box trials are stated to indicate that on a barren soil the use of the 

 cultures may be attended with some degree of success, but that on 



