1906.] Experiments with Calcium Cyanamide. 217- 



Both plots received in addition to the nitrogenous manure 4 cwt. 

 of superphosphate and i cwt. of sulphate of potash. 



Produce (tons). 

 Roots. Leaves. 



300 lb. sulphate of ammonia 23-5 4*9 



315 lb. cyanamide ... 22-0 ... 4*5 



The seed was Yellow Globe, sown on May 12th. The plant 

 was good and even, and the crop was lifted on October 21st. 

 The superiority of the sulphate of ammonia is too small to be 

 outside the limit of possible experimental error. It appeared,, 

 however, to be real and well marked in the early stages of 

 growth. 



3. Experiment with Mangels. — This experiment took place in 

 Barn field. The land was in very poor condition, and had 

 previously been cropped for many years with mangels with no 

 manure. Superphosphate and sulphate of potash were applied 

 to both plots as in 2. 



Produce (tons). 

 Roots. Leaves. 

 300 lb. sulphate of ammonia ... ... ... lO'O ... I"8 



310 lb. cyanamide ... ... ... ... ... in ... TO 



The seed was Yellow Globe, and was sown on May 8th, the 

 crop being lifted on October 26th. There was a very even plant,, 

 with few or no misses on both plots, but all the roots were small. 



4. Experiment ivith Mangels. — In this case the land (Rickyard 

 field) was in fair condition ; the previous crop was wheat. Both 

 plots received 36 lb. soluble phosphoric acid and 600 lb. sulphate 

 of potash (the latter amount in error). 



Produce (tons). 

 Roots. Leaves. 

 Sulphate of ammonia =- 40 lb. nitrogen ... ... 27*9 ... 4*5 



Cyanamide = 40 lb. nitrogen ... ... ... 28*9 ... 3*7 



As in other cases, the seed was Yellow Globe, sowing taking 

 place on May loth. The seed grew well from the start, and 

 there was an even plant with no misses. The crop was lifted 

 on October 20th. 



Results. — Taking the results together, and also considering 

 those obtained in 1904, it is clear that the nitrogen in calcium 

 cyanamide is practically of the same value as that in sulphate 

 of ammonia. There is a slight balance of evidence in favour of 

 the sulphate of ammonia, which is chiefly manifested in the 

 early stages of the growth of the crop, probably because the 

 cyanamide is a little slower in coming into action, but the 



