Basic Slag, Slag, Thomas's Slag 



necessary for nitrification and for the fixation of 

 ammonia and potash. Also it neutralises the acids 

 in the soil. It is thanks to this quality that basic 

 slag is so valuable in many soils, and that its use is 

 so advisable and ought to be popularised. It is 

 the phosphatic manure par excellence for acid land 

 in general, but its action is appreciable everywhere. 

 For a long time it was recommended, without 

 any particular reason, to apply slag in November, 

 regardless of the fact that that month was either not 

 soon enough, or too soon. Slag by itself cannot 

 penetrate deeply into the soil. It is useless, there- 

 fore, to apply it with this object m November. 

 In good slag the phosphoric acid is soluble in 

 weak acids, but the chemical reactions of the soil 

 are reduced to a minimum in the \vinter, and the 

 physiological reactions are reduced to nothing at 

 all, the plants not being in a state of vegetation. 

 The assimilability of the phosphates of the slag 

 are, above all things, dependent on the physiological 

 action of the roots of plants ; that is why their 

 effect is progressive. \\Tien the phosphate of the 

 slag is not assimilable it would become so better in 

 summer than in winter. 



On pastures it will give good results, even in 

 peaty soils where the superphosphates may be lost 

 in the drains. It is also the manure for sandy soils, 

 and at the same time for those which lack phosphoric 

 acid and limestone. 



It is basic slag that has made it possible, or at 

 any rate has greatly helped, to reclaim heather 

 land, and it is to basic slag that Belgium, Holland, 

 and Germany are indebted for their progress in 



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