1920.] 



Manures in December. 



881 



improving the quality of the herbage. The difference is not so 

 great as would be expected from the difference in solubility, 

 . and it seems clear that present-day analytical methods do not 

 deal satisfactorily with present-day slags; this subject is under 

 further investigation. Meanwhile, Mr. Kobertson's experi- 

 ments show that ground rock phosphate is distinctly useful on 

 grass land, being little, if any, inferior to some of the basic 

 slags. Farmers who have difficulty in obtaining a supply of 

 slag, therefore, may make trial of some of these mineral phos- 

 phates. Mr. Kobertson's results are as follows: — 



Manures, 200 lb 

 Po Or; per Acre. 



z 



'o . 





Hay, Cwt. per Acre. 







Boulder Clfiys. 



London Clay. j 



Chalk. 



B o 

 o -a 



_o 



S ID '/3 



S 



c _ 



S o . 



cS 



M 



11 



£ .« 1 



d 



g s>^ 

 •■^ > ^ 



eS 

 CO 



High Grade Basic Slag 



92 



30-9 





31 -7 







41-2 



Gafsa Rock Phosphate 



38 



30-5 



29-1 



29-7 



23-0* 



25 -Of 



38-7 



No i\iaiiu7-e 





20-3 



16-0 



21-7 





13-2 



31-1 



Open Hearth Fluorspar 

















Basic Slag (1) 



4.5 



32-8 





30-8 





- 



40-0 



do. do.. (2) 



20 





22-7 





188 



26-6 





do. do. (8) 



32 











16-0 





Low Grade High Citric 

















Sol. Basic Slag (1) 



93 



32-8 





31-6 







35-2 



do. do. (2) 



82 



32-3 





33-9 







40-2 



do. do. (3 ) 



91 





30-2 





22-5 



24-5 





do. do. (4:) 



80 











23-7 





Average Rainfall, 1st 

















May until Harvest 

















(inches) 





4-66 



6-91 



4 -88 



2'28 



3-26 



2-74 



do. 1st Ap7'il until 

















Harvest (inches) 





7-02 



9-35 



7-11 



4-64 



6-46 



5-26 



Egyptian phosphate. j Cambridge coprolites. 



The analyses of the crops gave the following results: — 



Type of 

 Vegetation. 



Farnham (Boulder Clay Soil). 



Horndon (London Clay Soil;. 



Plot 1. 

 Open Hearth 

 Bi.sic Slag 

 (Solubility 

 20%). 



Plot 2. 

 High Citric 



Soluble 

 Basic Slag 

 (Solubility 



91 %)• 



Plot 3. 



No 

 Manure. 



Plot 18. 

 Open Hearth 

 Basic Slag 

 (Solubility 

 20 %). 



Plot 17. 

 High Citric 



Soluble 

 Basic Slag 

 (Solubility 



91 °/o). ' 



Plot 16. 



No 

 Manure. 



Clovers ... 

 Grasses . . . 

 Weeds ... 

 Bare Space 



Pe?' cent. 

 27-1 

 45-0 

 160 

 11 -9 



Per cent. 

 50-2 

 33-3 

 13 -.5 

 30 



Per cent. 

 10-2 

 18-4 

 25-0 

 40-4 



Per cent. 

 43-8 

 31-8 

 13-3 

 IM 



Pt'r cent. 



46 - 2 



47- 2 

 1-4 

 5-2 



Per cent. 

 9-4 

 19-1 

 26-0 

 45-5 



