MANURES, 143 



jorin by the me of lime, it can escape (exce}tt in 

 very poor soils) only as it is taken up by roots to feed 

 the crop, and such exhaustion is certainly pi-ofitable? 

 and, so far as the organic parts are concerned, the 

 fertility of the soil will be fully maintained by the 

 decomposition of new roots and of organic manures. 



The only way in which lime can exhaust the earthy 

 parts of the soil is, by altering their condition, so that 

 plants can use them more readily. That is, it exposes 

 it to the action of roots. We have seen that fertili- 

 zing matter cannot be leached out of a good soil, in 

 any material quantity, nor can it be carried down to 

 any considerable depth. Ilence, there can be no 

 loss in this direction ; and, as mineral mattei 

 cannot evaporate from the soil, the oidy way 

 in which it can escape is through the structure of 

 plants. , 



If lime is applied to the soil, and increases tlm 

 amount of crops grown by preparing for use a larger 

 supply of earthy matter, of course, the removal of 

 earthy substances from the soil will be more rapid 

 than when only a small crop is grown, and the soil 

 will be sooner exhausted, — not by the lime, but by 

 the plants. In order to make up for this exhaustion 

 it is necessary that a sufficient amount of inorganic 

 matter be supplied to compensate for the increased 

 quantity taken away by plants. 



Thus we see that it is hardly fair to accuse the 

 hme of exhausting the soil, when it only improves its 

 character, and increases the yield. It is the crop 

 that takes away the fertility of the soil (the same us 



