46 STATE BOARD OF AGRICULTUIIE. 



and thus it is, too, that many of the economic manipulations are based 

 upon the habits of this life. The idiosyncrasies of germ life must be 

 studied if we are to gain in our knowledge of the practical manage- 

 ment of organic and inorganic substances for land fertilizers. 



If a fertilizer is of such a nature as to be thoroughly uftilizable by 

 plants, germs may be of little use, but usually such fertilizers are more 

 expensive and are not considered so good, perhaps because germs can 

 feed plants steadily Avith such quantities as are derived by their slow, 

 constant action, while a single addition of fertilizer does not fulfill 

 the mission but gluts for a time, then is largely washed away. 



The soil possesses much energy for plant growth which is latent. In 

 other words, in almost every soil there are constituents in sufficient 

 quantities to enable plants to grow. Even when worn out, soils are 

 frequently found to contain sufficient nitrogen, potash, phosphoric acid 

 and other ingredients. Under such conditions, those constituents which 

 should be utilized by the plants are tied up in such a manner as to be 

 useless. They must be rendered available to the plant if the soil is to 

 recover its worth. To accomplish this, the agents of change must be 

 present, must be properly fed, must be properly treated when the inert 

 chemical substances will respond to the living forces by production of 

 solvents which will burst asunder the apparently strong cords of chemi- 

 cal equilibrium. In other words, these life forces have the power of 

 introducing life into chemical death. Physical treatment assists bac- 

 terial activities, likewise fosters certain restorative conditions, all of 

 which contribute to the welfare of plant life. Work which has already 

 been done not only establishes the present of soil bacteriology, but 

 indicates experimentally a brilliant "future for this branch of the 

 science. It points to great possibilities in creating energy out of 

 apparently dormant material. In proportion to the amount of energy 

 that is introduced into the life activities of the soil by certain physical 

 management, in that proportion will certain chemical changes be initi- 

 ated and continued; or, in that i^roportion will certain energy pass 

 into chemical activity. 



PLANT BACTERIOLOGY. 



Under this heading may be pertinently considered the bacterial dis- 

 eases of plants, bacterial vegetable decay, and nitrogen abstraction and 

 assimilation from the air by certain bacterial nodular growths upon 

 roots. In the matter of bacterial plant diseases, there is a field which 

 has been as thoroughly worked in this country as anywhere, and which 

 has given to agriculturists an insight into certain drastic communica- 

 ble diseases that hitherto it was not our privilege to enjoy. Thi'ough 

 the arduous labors of Smith, many bacterial plant diseases have been 

 opened for study and this knowledge has been utilized in their control. 

 Whether it is going to be feasible to consider the, immunization of 

 species or the introduction of harder types or the treatment of diseases 

 after they are already started, remains to be determined in the future. 

 Some work already suggests future development along these lines. At 

 the present time there is not much to be said other than the fact, that 

 these diseases exist; that they are caused by bacterial forms; and that 

 their treatment seems to be quite uniform. 



Plant and vegetable decay taken in conjunction with fungus agents 



