2i6 Experiments with Calcium Cyanamide. [jul\% 



EXPERIMENTS WITH CALCIUM CYANAMIDE. 



Calcium cyanamide,* or " Kalkstickstoff/' the new manure ob- 

 tained by combining calcium carbide with the nitrogen of the 

 atmosphere, seems likely soon to come upon the market on a 

 commercial scale. Through the kindness of the Cyanid Gesell- 

 schaft of Berlin, a trial quantity was received by the Rothamsted 

 Experimental Station in 1905, and was used for barley and 

 mangels, with the results set out below. The material was a 

 fine black powder, which yielded on analysis 20'3 per cent, of 

 nitrogen ; it is thus weight for weight only a trifle poorer in 

 nitrogren than sulphate of ammonia, which contains about 20*5 

 per cent. In all cases it v/as compared with sulphate of ammonia •, 

 phosphates and potash being applied equally on both the trial 

 plots so as to provide a complete manure and match the nitrogen, 

 in the cyanamide against an equal amount of nitrogen in the 

 sulphate of ammonia. 



The manures were always applied separately and harrowed 

 in a few days before sowing the seed. The quantities are all 

 expressed per acre. 



1. Experiment with Barley. — This was carried out in Little 

 Hoos field, and followed swedes which were carted off. The 

 |and was in poor condition, and was unmanured for the previous, 

 crops. The plots also received 2 cwt. per acre of super- 

 phosphate (37 per cent.). . 



Dressed Grain. Weight per Straw. 

 Bushels. Lb. Bushel (lb). Cwt. 

 200 lb. sulphate of ammonia ... 37-5 ... 2,150 ... 57*3 ... 24 

 210 lb. cyanamide 34-3 ... 1,970 ... 57-5 ... 19 



The seed was Hallett's Chevalier, and was sown March 2nd, 

 the crop being cut on August 22nd. This was a good even 

 plant, standing up well. 



From the first the appearance of the plant indicated that the 

 sulphate of ammonia plot was a little the better and was pro- 

 viding more nitrogen for the crop. 



2. Experiment with Mangels. — Also conducted in Little Hoos 

 field. The land was in moderate condition, the previous crop 

 having been potatoes, which had received farmyard manure. 



* See Notes on Lime Nitrogen, yip^^ma/, May, 1905, (p. loi) and April 1906, 

 (p. 38). 



