CONTRIBUTIONS FROM THE WISLEY LABORATORY. 



613 



of the experiment) we find, as the following table shows, that there 

 is comparatively little difference in the final results obtained from the 

 use of the three manures, nitrate of soda, sulphate of ammonia, and 

 calcium cyanamide respectively. 



TABLE II. 



Yield in Three Years from Plots Manured with Nitrate of Soda, Ammonium 

 Sulphate, and Calcium Cyanamide. 











Total for three years 



Manure applied 



1908 



1909 



1910 

















Eoots 



Leaves 





Total 





lb. 



lb. 



lb. 



lb. 



lb. 





lb. 



Nothing .... 



129 



39i 



159i 



198i 



129i 





328 



Nitrate of soda . 



153 



56 



214i 



227 



196i 





423| 



Ammonium sulphate 



152 



65 



194i 



239 



172i 





411i 



Calcium cyanamide . 



173 



46 



187 



241 



165 





406 



It would appear, therefore, that for supplying nitrogen over the 

 whole growing period of the crop there is little to choose between these 

 three. The question of the rapidity of their action is referred to later. 



So far as can be judged from a single experiment the effects of 

 nitrate of lime are about equal to those of nitrate of soda, but for 

 reasons given below its use was discontinued. 



The following table is instructive. It represents the growth made 

 by the turnips in their early stages and indicates the ease with which 

 the plants could make use of the various manures applied before 

 sufficient time had elapsed for any great changes had taken place in 

 them. 



TABLE III. 

 Weight of Thinnings, 



Plot 



Manure applied 



"Weight of thinnings 



Row 1 



Row 2 



Row 3 



Total 







Grammes 



Grammes 



Grammes 



Grammes 



1 



Calcium cyanamide 



1,910 



2,247 



1,785 



5,942 



2 



Hydrated calcium cyanamide 



1,210 



1,510 



1,340 



4,060 



3 



No manure .... 



2,720 



3,044 



1,570 



7,334 



4 



Ammonium sulphate 



2,442 



2,687 



2,077 



7,206 



5 



Nitrate of lime 



5,775 



5,390 



5,507 



16,672 



6 



Nitrate of soda 



6,807 



7,702 



7,127 



21,636 



As was pointed out above, the quantities of manures applied were 

 such as to add equal quantities of nitrogen to each plot except No. 3 ; 

 the same quantity of seed was sown in each row on July 23, 1909, 

 and the plants were thinned to equal distances apart and the thinnings, 

 shaken free of earth, weighed on August 28, 1909. It will be seen 

 that the two nitrates stimulated growth much more than any of the 

 other manures. At that date the ammonium sulphate had had no 

 effect. The calcium cyanamide seems to have had a retarding influ- 

 ence, the effect in this direction of the hydrated calcium cyanamide 

 having been greater than that of the calcium cyanamide. 



