45 



any conditions that impoverish the soil, a dressing of from 

 $ cwt. to i cwt. per acre is useful and economical. On very 

 hungry or poor land, up to i cwt. may be given with effect. 

 In all cases of manuring barley with sulphate of ammonia, 

 it is important to remember the need of the crop of minerals, 

 both phosphates and potash. These may be present in the 

 soil, either as a natural constituent or as a residue from pre- 

 vious manuring ; but if not, they must be supplied as manure, 

 or the sulphate cannot give its full effect. 



OATS. 



With regard to this crop, there are no records available 

 of experiments carried out over long series of years such 

 as the wheat and barley experiments at Rothamsted and 

 Woburn. At the same time, the evidence we have on the 

 effect of sulphate of ammonia on oats is so free from contra- 

 dictions or anomalies, that we need have no hesitation in 

 accepting the conclusions arrived at. 



At Rothamsted, experiments on the continuous growth of 

 oats were carried out from 1869 to 1878 ; but after the first 

 five years, the plots dressed with nitrate of soda became so 

 wet that the crop was badly got in, and the plant was there- 

 fore irregular. Taking, therefore, the first five years only, 

 the average results obtained were as follows per acre per 



annum : 



TABLE XXIII. 



* Mineral manures are in all cases sulphates of potash, soda, and 

 magnesia, and superphosphate. 



Without minerals, ammonia salts and nitrate of soda gave 

 almost identical results ; but when minerals were given in 

 addition, the difference in the quantity of grain, though 

 slight, was in favour of ammonia salts, as was also the 

 weight per bushel. A somewhat unexpected point was the 

 larger proportion of the straw to the grain produced by the 

 ammonia salts. 



If we were to include with the above the yields of the last 

 four crops, obtained in the five years 1874 to i878inclusive, 

 the average result would be much more in favour of ammonia 



> * 



