l600 MANURES AND MANURING 



1 169 - Manurial Experiments with Manganese Slag in Germany — popp m., in FuhUnRs 



Laniioirtschaftlichc ZciliDi'^, Vol. 65, Nos. 15 and 16, pp. 354-360. Stuttgart, August i 

 and 15, 1916. 



Manganese slag is obtained in largQ quantities in Germany as a bye- 

 product in the manufactitre of ferromanganese and spiegleisen. Its 

 average chemical composition is given below : 



per cent per cent 



Manganese 24.4 Magnesia 6.3 , 



Silicic acid 30.5 Sulphur 1.2 



Alumina 9,8 Iron traces 



I/inie 33-4 



The manganese is insoluble in water, but slowly soluble in weak 

 acids. Its percentage occasionally rises to 30. 



A series of pot experiments were carried out in which the manurial 

 value of the manganese slag was compared with that of anhydrous manga- 

 nese sulphate. The slag was used in a powdered form similar in fine 

 ness to basic slag. It contained 18 per cent of manganese and 32.26 per 

 cent of silicic acid, and was applied to sandy soil made up of : 



per cent per cent 



Gravel 5.85 lyime 0.28 



Coarse sand 15.10 Phosphoric acid 0.14 



Fine sand 49-75 Potash 0.13 



Claj- 29.30 Nitrogen 0.15 



Each pot contained 10 kgs of soil and received i gm. phosphoric 

 acid, 1,5 gm. potash, 1,5 gm. nitrogen and 60 gms. of calcium carbonate 

 in the form of marl, besides dressings ranging fro 0.5 to 10 gms. of man 

 ganese either as sulphate or as slag. White Petkus oats were sown on 

 April 17 and harvested JiUy 17. Manganese slag increased the jdeld of 

 both grain and straw in proportion to the amount appHed except where 

 the maximum dressing was used. In small amounts (0.5 and i gm) man- 

 ganese sulphate was more effective than slag, but with the larger appli- 

 cations (2.5 and 5 gms). the order was reversed. Taking the maximum 

 increase in yield as 100, the results of the experiments are as follows : 



Amount of manganese Increase in >aeld due to manganese 



applied ' — - ' -^ ~-^ 



— Slag Sulphate 



gms. — — 



0.5 13 33 



i.o 44 52 



2.5 69 62 



5-0 • 90 57 



7.5 100 — 



lo.o gi — 



With manganese slag the grain was affected more than the straw ; 

 with manganese sulphate the reverse was the case. Increase in yield due 



