191 1.] Summary of Agricultural Experiments. 417 



208 lb. superphosphate, 200 lb. kainit; (2) 100 lb. sulphate of ammonia, 

 208 lb. superphosphate, 50 lb. muriate of potash. These both gave an 

 increase of about 10 cwt. of hay over the unmanured plot, which, at 

 ^3 per ton, is calculated to leave a profit, apart from residual value, 

 after allowing for the cost of the manures, of about 105. per acre. 



Manuring of Potatoes (Midland Agric. and Dairy Coll., Bull. 3, 

 1910-11). — A trial of the effect of artificial manures in addition to the 

 usual farmyard manure was made at four centres in Lincolnshire and 

 at the College farm. The conditions and soil varied somewhat, and 

 at one centre no farmyard manure was used. The best yield was 

 obtained from a mixture of i| cwt. sulphate of ammonia, 4 cwt. 

 superphosphate, and i\ cwt. sulphate of potash per acre, with from 

 12 to 20 tons of farmyard manure. This dressing cost 445. per acre, 

 and gave an average increase in crop over the plot without artificials 

 of 32 cwt. of ware potatoes. Various other mixtures, including nitrate 

 of lime, calcium cyanamide, fish meal, and some proprietary potato 

 manures gave smaller increases for a similar cost of manure. 



Manuring of Mangolds (Midland Agric. and Dairy Coll., Bull. 4, 

 1910-11). — In the course Of preliminary trials extending over five years, 

 a standard dressing of artificials for use with farmyard manure for 

 mangolds was determined, and during three subsequent years this 

 dressing has been further tested, and has given the best results. It 

 is made up as follows : — Sulphate of ammonia, 100 lb., applied at 

 seeding; nitrate of soda, 130 lb., at singling; superphosphate, 750 lb., 

 at seeding; either sulphate or muriate of potash, 120 lb., at seeding; 

 and common salt, 2.\ cwt. applied in March. This was used in addition 

 to from 10 to 25 tons per acre of farmyard manure. It cost 55s. 6d. 

 per acre, and in any year always on the average gave a profit, the 

 mangolds being valued at 125. 6d. a ton. 



Superphosphate or Mineral Phosphates for Swedes (Midland Agric. 

 and Dairy Coll., Bull. 7, 1910-11). — It is commonly thought that soluble 

 phosphates are desirable as being more available for the immediate 

 requirements of the plant, but there is every reason to believe that soon 

 after they are applied to the soil they combine with lime, and are more 

 or less completely changed to the insoluble form. There are conse- 

 quently good grounds for thinking that the practical value of soluble 

 phosphates is due, not so much to their being taken up in that state 

 by the plant, but to the solubility ensuring minute sub-division and 

 even distribution throughout the soil particles. If fineness of division 

 is the object in view, it was thought that an experiment could be 

 usefully carried out to ascertain whether the same object could be 

 obtained by reducing ordinary mineral phosphates to a fine powder, 

 thus saving the cost of treating them with acid to form superphosphate. 

 The experiment forms, therefore, a comparison between the mechanical 

 and chemical preparation of phosphates. Nitrate of lime is also being 

 :ested, as well as the effect of ground lime, in order to see whether there 

 s reason for the opinion that insoluble phosphates are more beneficial 

 mi soils lacking in lime and rich in organic matter. 



This report contains the results which have been given by 500 lb. 

 Superphosphate, 173 lb. Florida phosphate, and 250 lb. Charleston 

 >hosphate, these amounts containing equal quantities of phosphate. 

 j\-S the experiments have only been in progress for one season it would 

 j>e premature to draw conclusions at present, but they are sufficient 



