in insoluble silicates containing potash and still be starving for soluble 

 potash. Lime decomposes the soil silicates, thus setting the potash 

 free. 



"The presence of sufficient lime in the soil prevents the soluble phos- 

 phoric acid applied in fertilizers from satisfying its hunger for a base by 

 combining with iron or alumina, which is undesirable because phos- 

 phates of iron and alumina are very insoluble. When lime is present, 

 the phoshporic acid will take this by preference and the reverted phos- 

 phate thus formed is much more valuable than would be the phosphates 

 above mentioned." (W. P. Brooks.) 



Lime hastens the decay of all organic substances which may be in the 

 soil. Green manures and barnyard manures are of little use the first 

 year or two if a sufficient amount of lime does not exist in the soil to pro- 

 mote decomposition. 



Injm'ious iron compounds in the soil are rendered harmless by the free 

 use of lime. 



Lime stimulates to activity plant food in peaty soils, drained lands 

 and swampy lands which have been under water for a long time. 



The physical effect of lime on soil is also very marked. 



All soils, except those of a light, sandy nature are made mellow and 

 friable by the use of lime. 



Dense clay soils are especially improved by being treated with lime. 

 Often clay soils are so compact that they are impervious to both air and 

 water. Prof. Brooks has the following to say regarding clay soils. 



"As the result of an experiment, it is reported that a layer of water 

 about two inches thick required 26 days and 19 hours to pass through a 

 clayey soil. After the soil was mixed with 2.5 per cent of lime, the same 

 quantity of water passed through it in 17 hours. The explanation of this 

 remarkable effect of mixing lime with clayey soils is that it causes the 

 exceedingly fine particles of clay to gather in little balls. Between these 

 little balls of clay, air and water circulate as between grains of sand and 

 it is to this particular effect chiefly that the great improvement in the 

 heavy soils resulting from Uming is due. 



The fact that certain fertilizers, among which kainit, muriate of 

 potash and nitrate of soda may be named, when freely used make the 

 soils compact, has been pointed out. The use of these fertilizers also 

 increases the tendency to formation of a crust at the surface. If such 

 a crust be broken up by cultivation or hoeing, it forms again after the 

 next rain. It is practically impossible under these circumstances to 

 keep the soil in suitable tilth. The use of lime in connection with such 

 fertilizers will prove an effectual preventive of crust formation. In 

 European agriculture, air-slaked lime is generally employed in connec- 

 tion with nitrate of soda or potash salts." 



Sandy soils become more compact and hold humus better, thereby 

 absorbing and retaining moisture longer if they are well limed. 



