528 EXPEEIMENTS WITH PHOSPHATES AND SlAGS. [SePT., 



Field Experiments on Arable Land in Northern Ireland. — 



The Essex Experiments deal entirely with grass land, the con- 

 ditions being materially different from those under arable con- 

 ditions. In the former case the gTowing season is long, the 

 manures can be conveniently applied in the autumn, and 

 rapidity of action is not of such importance as on arable land. 



In conjunction with Mr. D. E. Aiken, Mr. James Bradshaw, 

 Mr. H. S. Cuthbertson, and Mr. P. T. O'Hare, County Agri- 

 cultural Instructors for Londonderry, Armagh, Down, and 

 Antrim respectively, a series of rotation experiments was begun 

 in Northern Ireland in the spring of 1921 with the object of 

 obtaining information as to the value of Gafsa phosphate under 

 arable conditions. The manures were applied to the turnip 

 crop in the drill in April. 



fTABLE 5. EoTATION EXPERIMENTS WITH VARIOUS PHOSPHATES. 





A^;trim. 



Armagh. 



Down. 



LONDON- 

 DEERY. 



No farmyard 

 manure. 



With 

 farmyard 

 manure. 



With farmyard 

 manure. 



With 

 farmyard 

 manure. 







Clough- 

 mills . 



Bally- 

 nure. 



Bess- 

 brook. 



Bally- 

 walter. 



Crossgar. 



Druma- 

 duff. 



No phosphates . . . 



Superphosphate ... 

 Gafsa phosphate ... 

 Basic Bessemer slag 

 Open hearth high 



sol. slag 



Steamed bone flour 



tons. cwt. 

 4 14 



18 

 16 10 



18 15 



16 15 



19 10 



tons, cwt, 



only 

 3 turnips 

 35 12 

 39 3 

 38 6 



38 12 



tons. cwt. 



30 5 



34 7 

 32 



3 



tons, cwt, 



24 6 



25 10 

 27 6 



26 8 

 25 10 



tons. cwt. 

 14 4 



25 7 



27 18 



28 3 

 25 14 



tons. cwt. 

 25 13 



28 8 

 28 



28 4 



29 1 



In the Antrim Experiments no farmyard manure was applied, 

 but in its place each plot received IJ cwt. sulphate of ammonia 

 and IJ- cwt. muriate of potash per acre. The dressing of phos- 

 phate was equivalent to 200 lb. of phosphoric acid per acre 

 (approximately 10 cwt. of 40 per cent. slag). 



In Counties Armagh, Down and Londonderry the plots received 

 a dressing of 15 tons per acre of farmyard manure. With the 

 exception of the various phosphates no other artificials were 

 applied. At these centres the phosphates were applied at half 

 the previous rate, i.e., at the rate of 100 lb. of phosphoric acid 

 per acre, approximately equivalent to 5 cwt. of 40 per cent, slag 

 per acre. 



