Calcareous Improvements 



In soils where free acids are encountered in con- 

 siderable quantity — such as peaty soils — lime would 

 be used to absorb them. It acts very rapidly and 

 thoroughly ; for while limestone can neutralise 

 acetic and humic acids, for example, only lime is able 

 to neutralise carbonic and tannic acids. Lime alone 

 is capable of transforming the organic matters of the 

 vegetable mould and of producing ammonia (NH3) 

 from the nitrogenous organic matter. It is thanks 

 to these two capacities that we are able to conquer 

 waste places, acid soils that are too humiferous, and 

 especially waste soils of granitic origin. 



Its use generally produces unforeseen effects, 

 because the lime hastens the disintegration of 

 alkaline silicates, freeing the potash and placing it 

 at the disposal of the plants. We have said that 

 when lime has done its work it does not remain in 

 the soil as quicklime (CaO), but is transformed in 

 proportion to the extent of its action. A great part 

 thus becomes carbonate of lime. This is very im- 

 portant, because quicklime, in spite of the services 

 it renders, will become harmful and prevent the soil 

 from enjoying the advantages which it had procured. 

 Thus lime impedes nitrification, or stops that which 

 is taking place, whilst limestone not only helps it 

 but is indispensable. To these qualities are due 

 some of the varying results obtained by their use. 

 It is calcium carbonate which gives to the nitric 

 ferment the CO2 which it needs, and which moreover 

 neutralises the nitric acid as it is formed. Hence 

 without calcium nitrification ceases. 



In the chapter on phosphates we see, d propos 

 of the reversion of phosphates, that the soluble 



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