24:3 



over it as evenly as possible a little soil taken from a rich garden which 

 has been k pt in excellent cnltivation. The amount of pi mt fool added 

 in such a soil would not be of any great importance, but the nitrifying 

 organisms thus distributed would rapidly grow in the favourable envi- 

 ronment in which they were found and the inert nitrogen of the fi -id 

 be thus speedily prepared for the wants of the growing crop 



The action of stable manure is another instance of the great benefit 

 which is derived from manuring a field with nitrifying organisms It 

 is well known that the nitrifying ferments of decomposing stable 

 manure are particularly numerous and vigorous. The production of 

 ammonia in a pile of stall manure is often so rapid, as to be distinctly 

 noticed by the passers-by from the odour produced. It has long been a 

 matter of wonder among agronomists to find stall manure, when scat- 

 tered over field, producing fertilizing results far in excess of what 

 could be expected from quality of plant food contained therein. In the 

 light of the facts set forth above, however, these results are no longer 

 surprising. In the distribution of the manure large numbers of a par- 

 ticularly vigorous species of nitrifying organisms are incorporated with 

 the soil, and these and their progeny continue to exercise their activity 

 upon the inert nitrogen of the soil when the more easily nitrifiable por- 

 tions of the stall manure are exhausted. The result brings to the 

 attention of the scientific agronomist an entirely new factor in the pro- 

 cess of fertilisation. Even in the poor soils chemical analysis often 

 discovers quantities of plant food which seem amply sufficient to pro- 

 duce remunerative crops. The true theory of fertilisation, therefore, 

 not only looks to the addition of appropriate plant foods to a soil defi- 

 cient therein, but also to the making available the stores of plant food 

 already present. 



FERTILISING FERMENTS. 



When the soil is pract cully free from albuminoid bodies and contains 

 but little humus, the attempt to develop a more vigorous nitrifying 

 ferment would be of little utility. Even in a soil containing a con- 

 siderable degree of humus, it may be found that its nitrogen content has 

 been so far reduced as to leave nothing practically available for the 

 activity of nitrification. In such cases the only rational method of 

 procedure is the application of fertilisers containing nitrogen. In other 

 cases where the lack of fertility is due to the extension or attenuation 

 of the nitrifying ferment, remunerative results may be obtained by some 

 process of seeding similar to that described above. It is entirely within 

 the range of possibility that there may be developed in the laboratory 

 species of nitrifying organisms which are particularly adapted for action 

 on different nitrogenous bodies. For instance, the organism which is 

 found most effective in the oxidation of albuminoid matter may not be 

 well suited to convert amides or the inert nitrogen of humus into nitric 

 acid. We have already seen the day when the butter maker sends to a 

 laboratory for a ferment best suited to the ripening of his cream. It 

 may not be long until the farmer may apply to the laboratory for 

 particular nitrifying ferments to be applied to such special purposes as 

 are mentioned above. Because of the extreme minuteness of the or- 

 ganisms the too practical agronomist may laugh at the idea of producing 

 fertility thereby, and this idea, indeed, would be of no value were it not 

 .ior the wonderful facility of propagation which an organism of this kind 



