1910.] Summary of Agricultural Experiments. 63 



ingredients — a "complete" manure — will give the heaviest yield of 

 grain, but will not necessarily be the most profitable. 



(4) The use of phosphatic and potash manures unaccompanied by 

 soluble nitrogenous manure may seriously reduce the yield of grain 

 below that obtainable on the unmanured soil. 



(5) Provided the most profitable combination of manures has been 

 ascertained, as stipulated above in (3), a substantial profit may be 

 expected from the increase in yield of saleable grain alone, to which 

 may be added the value of the extra yield of straw. 



Taking the most remunerative plot in each year, the increase in the 

 yield of saleable grain, when valued at 27s. per qr., has shown in every 

 case a substantial surplus over the cost of the manures, the average 

 surplus for the nine experiments being ijs. lod. per acre. Even with 

 the least remunerative of the plots receiving nitrogenous manure, in 

 only three of the nine experiments did the increase in the yield of 

 saleable grain not cover the cost of manuring, and on the average of 

 the nine a surplus of 35. 6d. per acre is indicated. 



(6) The use of guano is less profitable than an equal expenditure on 

 a suitable mixture of " artificial " manures. 



(7) The malting value of the grain is, in general, not appreciably 

 affected by the use of artificial manures, their influence, if any, being 

 quite overshadowed by the influence of the climatic conditions during 

 the ripening period. 



In the best barley season (1901) during the seven years covered by 

 the experiments, the finest malting barley was that grown with the aid 

 of a mixture of nitrate of soda, superphosphate, and kainit. 



(8) With regard to the use of salt the results obtained in these 

 experiments are not quite conclusive. Further tests are necessary before 

 reliable general conclusions on this point can be formulated. 



Samples of the barleys were analysed in six years in order to ascer- 

 tain to what extent the application of nitrogen, phosphate, and potash in 

 the manure might have affected the proportion of those ingredients in 

 the grain. The results obtained are given in this report, and it is 

 considered to be quite clear that the proportions of nitrogen, phosphate 

 and potash are not directly affected by the manures applied to the 

 crop. The question of the connection between the proportion of these 

 ingredients and the malting quality of the barley is also discussed, but 

 no direct connection has yet been traced. 



Continuous Corn Growing (Roy. Agr. Coll., Cirencester, Scientific 

 Bulletin No. 1, 1909). — In 188 1 it was decided to start this experiment 

 on continuous corn-growing. Twenty-four plots of i -acre each were 

 laid out, and until 1885 were cropped without manure, in order that 

 some idea might be formed of the capacity of each plot, and to equalise 

 and reduce the condition of the soil, which varied considerably. In 

 each year afterwards various manures were applied, and barley was 

 grown continuously for seven years. 



On the average for the seven years superphosphate and potash 

 together gave no increase in the crop. Farm-yard manure at first gave 

 little increase, but as residues accumulated in the soil there was a 

 distinct increase in yield of both grain and straw. In seven years the 

 average increase over the unmanured plot was 3 bushels of grain and 

 4 cwt. of straw, with 7 tons per acre of manure, and 8| bushels of grain 



