Improving the Condition of the Soil 



phosphates are rapidly indissolubilised in the soil by 

 becoming insoluble phosphates of Ca, which practi- 

 cally prevents their loss by drainage. But on the 

 other hand limestone promotes the solubilisation of 

 phosphates of iron and aluminium already existing or 

 formed at the same time as the insoluble phosphates 

 of Ca. The water charged with CO2 penetrates the 

 soil attacking the insoluble limestone and rendering 

 it soluble in the form of bi-carbonate of calcium. 

 (This soluble calcium forms by evaporation the 

 stalactites and stalagmites of caves.) But in 

 solution it possesses one important property. It 

 is capable of coagulating clay. Clay swells in water. 

 The soluble carbonate coagulates it and these clayey 

 calcareous coagulum facilitate the circulation of 

 water in the soil. This enables the soil to dry more 

 rapidly. Freed of its excess of water the earth is 

 much easier to work and much earlier in season. 

 This fact is greatly appreciated in stiff clayey 

 country where the spring can be greatly retarded 

 because the moisture makes the groimd too sticky. 

 With regard to humus we also see that the 

 limestone coagulates the humic acid and that with 

 this the lime forms humates. We know too that 

 limestone has the power to enable humus and clay 

 by capillary action, to fix the manures and to trans- 

 form them into carbonates, thus preventing the 

 prevalence of ammonia, potash, and of phosphates. 

 The lime, while waiting to be transformed into 

 carbonate which encourages nitrification and con- 

 sequently the production of nitrate, has the advan- 

 tage of freeing the ammonia, which is immediately 

 accessible for the plants. 



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