50 



salts. But, as has been already pointed out, mangels 

 grown without farmyard manure form only a small pro- 

 portion of the whole area under the crop, so this supe- 

 riority of nitrate of soda is relatively unimportant. 



SULPHATE FOR MANGELS IN ROTATION. 



These results obtained at Rothamsted are fully con- 

 firmed by many other experiments carried out on farms in 

 all parts of the country. For example, in an experiment 

 of the Norfolk Chamber of Agriculture in 1886,* on light 

 loam at Whitlingham, on mangels grown without farm 

 manure, a given quantity of nitrogen as nitrate of soda 

 gave a distinctly greater weight of roots than sulphate of 

 ammonia. 



In the same year, the experiments of the Essex Agricul- 

 tural Society, in which farmyard manure was used, showed 

 an average advantage in weight of roots of only i4cvvt. per 

 acre from the use of nitrate of soda, compared with sulphate 

 of ammonia ; and from what we have seen of the 

 Rothamsted results, it is probable that the actual feeding 

 value in this case would be in favour of sulphate of 

 ammonia. 



A good deal of difference of opinion exists amongst 

 farmers as to whether nitrogenous manures should be 

 applied to mangels with the seed or as a top-dressing later. 

 The experiments of the Essex Agricultural Society referred 

 to above, throw light on the question. Taking the re- 

 sults of strictly comparable plots, we obtain the following 

 averages : 



TABLE XXVIII. 



Nitrogen applied Nitrogen applied 

 with Seed. in July. 



Tons Cwt. Lbs. Tons Cwt. Lbs. 



Average of nitrate of soda plots ... 24 12 54 .. 25 3 56 

 Average of sulphate of ammonia plots. 24 17 2 . . 23 11 8 



There is not very much difference shown here, except 

 that evidently sulphate of ammonia should be applied at 

 seed time, and not as a top dressing later in the year. 

 Nitrate, on the other hand, was somewhat more effective 

 as a top dressing than when sown with seed. 



Judging from the results of experiments, therefore, we 

 may conclude that when farmyard manure is used sulphate 

 of ammonia will yield, on the average, an almost equal 

 weight of roots per acre, compared with the produce of 

 nitrate of soda particularly if there is also a plentiful 

 supply of phosphates and potash, either in the soil or in the 

 manures used. The feeding value per acre is also probably 

 higher when sulphate of ammonia is employed than with 

 nitrate of soda. Without farmyard manure, nitrate is 



* " Journal of the Royal Agricultural Society of England," Vol. XXIII., 

 S.S., Part I. 



