184 



EXPERIMENTAL TAIiUS 



Composition of ' Natural Fertilizer.' 



2 GEORGE V., A. 1912 



This rock contains, it will be seen, considerable, though somewhat variable, 

 amounts of carbonate of lime and organic matter. The amounts of phosphoric acid 

 and nitrogen do not exceed those in many soils, and as regards availability are cer- 

 tainly not more valuable. Potash is absent, or practically so. It is evident, therefore, 

 that this material is not in any sense comparable to commercial fertilizers, which are 

 characterized by notable percentages of nitrogen, phosphoric acid and potash, more or 

 less immediately available for plant growth. 



Though not a fertilizer in the ordinary acceptation of the word, this rock in the 

 finely ground condition might act as an ' amendment ' for certain classes of soils. 



The benefit from its use would be due chiefly to the carbonate of lime it contains, 

 and to some extent possibly to the influence it would exert on the physical condition 

 or texture of the soil. It might, for these reasons, be expected to improve peaty and 

 muck soils, heavy clay loams, those which are sour, ill-drained and all those naturally 

 deficient in lime. These benefits are, of course, those which might be expected from 

 any ordinary limestone applied in a fine condition. 



LIMESTONES. 



Attention has been directed in recent years to the agricultural value of finely- 

 ground limestone, not merely to furnish lime when the soil is deficient in this element, 

 but to correct sourness, promote nitrification and improve tilth. While we have as yet 

 very little direct testimony in Canada on the use of ground limestone, we may safely 

 predict a favourable response when applied to such soils as we enumerated when 

 speaking of the use of the so-called ' Natural Fertilizer,' quarried and ground in 

 Nova Scotia. It must not, however, be supposed to act as a panacea for all soil 

 troubles, nor can its use alone be expected, even when a good rotation is followed, to 

 maintain fertility. It does not supply humus-forming material (so necessary for the 

 conservation of moisture and the 'life' of the soil) as do the farm manures, nor does 

 it contain the more important elements necessary for plant growth — nitrogen, phos- 

 phoric acid and potash — as do both manures and fertilizers. It cannot, therefore, be 

 regarded in any sense as a substitute for these, nor as we have pointed out, can it be 

 regarded as a newly discovered material that can solve satisfactorily all soil problems. 

 Experience throughout the known agricultural world has made very clear the high 

 fertility of soils naturally rich in lime and the excellent character of the crops and 

 of the stock raised thereon. It has also taught us concerning the use and abuse of 

 lime; how it may be used occasionally to advantage, but also how its exclusive find 



