1922.] Experiments with Phosphates and Slags. 601 



tinguishable from the untreated by their brighter and healthier 

 colour and by the double crop of hay which they carried. Samples 

 of hay were collected from each plot, and the results are set 

 out in Table 1 and illustrated Fig. 6. 



Table 1. — "Botanical Composition of the Hay by Weight 

 AT Martins Hearne Farm. 



Soil : Boulder Clay. Manures sown : 28th February, 1917. 

 Sample taken : 9th July, 1919. 





Plot 1. 



Plot 2. 



Plot 3. 



Plot 4. 



Plot 5. 



Plot 6. 





Open 



Open 













Hearth 



Hearth 





Gafsa 



Egyptian 



Algerian 





(Fluor- 



High 



No 



Rock 



Rock 



Ijock 





spar) 



Sol. 



Manure. 



Phos- 



Phos- 



Phos- 





Basic 



Basic 





phate. 



phate. 



phate. 





Slag. 



Slag. 













per cent. 



per cent. 



per cent. 



percent. 



per cent. 



per cent. 



Clovers ... 



trace 



trace 



trace 



trace 



trace 



trace 



Grasses ... 



85-2 



88-1 



58-5 



82-6 



96-7 



95-8 



Weeds 



14-8 



11-9 



41-5 



17-4 



3-3 



4-2 



Composition of 



THE Grasses by Weight. 





Lolium perenne 



9-9 



22-0 



6-8 



26-9 



198 



170 



Phleum prateuse 



6-0 



7 '7 



2-8 



4-5 



.0-7 



1-9 



Cynosurus crystatus ... 



20-6 



U-7 



10-8 



25-2 



28-7 



10-6 



Poa trivialis 



1-8 



12-0 



0-6 



10-9 



7-3 



9-5 



A vena flavescens 



1-3 



1-4 



0-6 



1-0 



1-3 



0-6 



Festuca ovina ... 





0-9 











Holcus lanatus ... 



32-5 



29-7 



44-3 



18-0 



17-0 



29-0 



Agrostis alba 



0-7 



2-6 



6-8 



4-5 



4-8 



11-2 



Anthoxanthum odoratum 



27-7 



9-0 



27-3 



9-0 



15-4 



20-2 





100-0 



100-0 



100-U 



100-0 



100-0 



100-(i 



Superior grasses 



39-1 



58-7 



21-6 



68-5 



C2 8 



39-6 



I uf erior grasses ... 



60-9 



41-3 



78-4 



31-5 



37-2 



60-4 



It is evident from the results that the action of the various 

 phosphates has not been confined to the clover. They have had 

 a very marked effect on the development of the grasses. The 

 extent of the action is best shown by grouping the gi*asses into 

 good or superior grasses and bad or inferior grasses, including 

 in the latter category Yorkshire Fog (Holcus lanatus), Bent Grass 

 (Agrostis alha) and Sweet Vernal Grass (Anthoxanthiin odora- 

 tum'). It will be seen from Table 1 and Fig. 6 that the High 

 Soluble Slag, Gafsa rock phosphate, and Egyptian phosphate 

 have given precisely similar results. Algerian phosphate does 

 not seem to have been quite so good as the others, whilst the 

 open hearth low soluble fluorspar slag, although it has produced 

 a marked improvement, is nevertheless not so effective as the 

 other phosphates. 



