524 EXPEEIMENTS WITH PlIOSPHATES AND SlAGS. [SePT., 



The results are set out in Table 3 : — 



Table 3. — Weight of Hay at Great Mulgraves, 



HORNDON-ON-THE-HiLL . 



[Dressing 200 lb. P2O,, per acre unless otherwise stated. 







Citric 









Plots 





solubility 



Hay (in cwt. per acre). 



Manure 



of the 













phosphate. 























per cent. 



1918 * 



1919 



1920 



A 



No manure... 





— 





4-5 



B 



Cambridge coprolites 



25 



— 





15 9 







Liiiiic ctu icitc UL X tuil pel cid U ... 





— 





5 



D 



Rough slao^ (double dressing) 





— 





17-2 



1 



Florida pebble phosphate (fine) 



19 2 



14-2 





17-0 



2 



1) ?5 ?9 y\^\jcvt.o^j 



Algeri m phosphate (fine) 



18 '2 



13-7 





14-7 



3 



35-7 



U-7 





21-5 



4 





33 -4 



U-9 





19-7 



5 



Open hearth basic slag : high sol. 



91-2 



18-8 





23-2 



6 



No manure... 





11-1 





6-4 





Gafsa roclc phosphate (coarse) 



38-6 • 



17*8 



<v 



22 '3 



8 





38'6 



18-4 



m 



22-2 



9 



Tunisian ,, (fine) 



26-0 



17-9 





23-2 



10 



,, ,, (coarse) ... 



23-9 



19-2 





23-8 



11 



FfvntinTi ^finp^ 



37-0 



23-6 





23-6 



12 



5 5 ^5 ^CUctXoCI ... 



34*7 



22-5 



a 



25-1 



13 



Superphosphate (200 lb. P2O5 per 











acre) 





27-0 



>^ 

 ,^ 



23-0 



14 



Superphosphate (50 lb. P2O5 per 













acre) 



— 



25-9 



CD 

 N 



12-3 



15 



Superphosphate (200 lb. PoO, per 







OS 



bi) 







acre) — 1 ton of ground lime per 











acre 





23-4 



m 

 % 



27 '2 



16 



No manure 





15*5 





()-4 



17 



Open hearth basic slag : high sol. 



91 -2 



22-5 



28-8 



18 



,5 55 55 fluorspar sol. 



20-1 



18-8 





16-8 



19 



1 cwt. ferrous sulphate per acre... 





13-6 





6-4 



E 



Lime at rate of 1 ton per acre ... 









5-4 



F 



Cambridge coprolites 



25-0 







15-1 



G 



Rough slag 









10-4 



H 



Cleveland phosphate 



18-9 







19-0 



K 



No manure 









5-0 



L 



Florida soft phosphate 









13-0 





Average gain, Plots 1 to 5 and 7 













to 13 and 15, 17 and 18, over 













plots 6 and 10 ... 









25 % 





Rainfall, May 1st till harvest (in 

 inches) ... 















2-25 



l-78t 



5-34 





Date of cutting 





July 8 





Aug. IG 



* Phosphates not applied till Feb. 28th. 

 t Rainfall, May 1st to June 30th. 



The Basic Slags, and the Gafsa, Algerian, and Egyptian phos- 

 phates, were from the same bulk as those used in the previous 

 experiments. 



The various phosphates were applied too late in 1918 for them 

 to have much effect that season. During 1919, a dry season, the 



