406 Summary of Agricultural Experiments, [aug., 



this fertiliser produced the largest turnip crop, a good barley crop, and 

 distinctly the largest hay crop. The total value of the three crops on 

 this plot was ^28 185. 6d., as compared with the next highest result 

 of £26 175. 6d. per acre from the superphosphate plot. 



Green Manuring (Journal of the Royal Agricultural Society, Vol. 69, 

 IQ o8). — Experiments in green manuring have been carried on for a 

 number of years at Woburn, and mustard ploughed in has always given 

 a better corn crop than tares. As explained in this Journal (December, 

 1908, p. 708), investigations have shown this to be due to the alteration 

 produced in the physical condition of the soil. 



The experiments in 1908 fully confirmed the observations of previous 

 years, and showed that on this soil wheat following rape and mustard 

 ploughed in gave the best crops, while the smallest crops were obtained 

 from wheat following tares. The plots which received lime in 1904 

 were generally superior to the corresponding ones to which mineral 

 manures had been applied. 



Calcium Cyanamide (Journal of the Royal Agricultural Society, Vol. 69, 

 1908). — A comparison was made between sulphate of ammonia at the 

 rate of £ cwt. per acre, applied as a top-dressing to barley, and 96*3 lb. 

 of calcium cyanamide, which was found to supply the same amount of 

 nitrogen. The results were greatly in favour of calcium cyanamide. 

 It is pointed out, however, that the Woburn soil is decidedly deficient 

 in lime, and is liable to suffer some ill effects from sulphate of ammonia. 

 Calcium cyanamide contains a material quantity of lime, and to this 

 fact is to be attributed in large measure the better crop obtained with 

 the new material. 



Calcium Cyanamide and Nitrate of Lime (Transactions of the High- 

 land and Agricultural Society, Fifth Series, Vol. XXL, 1909). — Mr. 

 James Hendrick, Chemist to the Society, gives some information as 

 to the new nitrogenous manures, nitrate of lime and calcium cyan- 

 amide, and states that the general result of experiments carried out in 

 Scotland has been to show that calcium cyanamide is capable of giving 

 as great an increase in cereal crops as the better-known manures, and 

 that there is little difference, weight for weight of nitrogen, between 

 it and nitrate of soda or sulphate of ammonia. 



With turnips, the results obtained on the average from calcium 

 cyanamide were not as good as those obtained from the application of 

 an equal amount of nitrogen in the form of sulphate of ammonia. 



With regard to the question of the possibility of calcium cyanamide 

 in its crude state proving injurious to germinating seeds, this point was 

 tested by Mr. Hendrick in two years by applying the fertiliser to one 

 plot ten to twenty days before seeding, and to another plot with the 

 ^seed. On the average, no difference was observed. The germination 

 did not appear to be affected, and the cyanamide appeared to undergo 

 change rapidly enough in the soil to be available for the crop, even when 

 it was sown at the same time as the seed. 



Nitrate of lime has, on the average, given rather better results than 

 those given by nitrate of soda supplying an equal weight of nitrogen. 

 This is probably due to the presence of the lime. Mr. Hendrick states 

 that it was noticed again and again in the field experiments that when 

 the plots which had received equal amounts of nitrogen in the different 

 forms of nitrate of soda, sulphate of ammonia, cyanamide, and nitrate 



