PROCEEDINGS OF SECTION K. 643 



The trend of recent research in agricultural science has brought 

 forcibly home to us the fact that the function of fertilizers is not 

 restricted to the duty of supplying plant-food to the growing crop. 

 Under certain circumstances, indeed, this function is in abeyance, 

 in the absence of sufficient water, for example, or in the presence of 

 unfavorable soil-conditions, the action of fertilizers is almost 

 negligible, and it is our lack of understanding of these conditions 

 that has been the frequent cause of want of success in the use of 

 manures. 



The idea that failure in plant-px'oduction is due solely, or even 

 chiefly, to deficient plant-food in the soil is no longer tenable. 

 Recent investigations have brought to light a host of other causes of 

 infertility, but the idea still persists at the back of many soil 

 analyses tJiat the determination of the amount of certain specified 

 plant-foods dissolved by specific solvents from the soil is a certain 

 guide to the nature of the manuring required. As a matter of 

 fact, neither the chemical composition of the soil, nor of the crop, 

 affords any certain basis on which advice as to manuring can be 

 given . 



A. D. Hall and E. J. Russell {Journal Agricultural Science, 

 vol. 4, p. 182), dealing with the results of a soil survey of the south- 

 et stern counties of England, draw, amongst other general con- 

 elusions, the following having special reference to the connexion 

 between the composition of the soil and plant. " We are not as 

 yet in a position to deduce the agricultural properties of a soil, 

 either its behaviour under cultivation or its adaptability to par- 

 ticular crops, except in the roughest general fashion." 



In dealing with a number of typical wheat-soils, the authors 

 say " chemical analysis of these soils revealed no connexion be- 

 tween their chemical composition and th^ir suitability for wheats," 

 and the same remark applies no doubt to other crops. They also 

 point out that excess or deficiency of any particular plant-food, such 

 as nitrogen, does not necessarily imply a fertile or infertile soil. 



Even in the case of calcium carbonate they show that many soils 

 poorly supplied with this ingredient are not benefited by the appli- 

 cation of lime, whereas for other soils examined containing the 

 same, or a greater proportion, liming is essential. They find that 

 *■ other things being equal, dry soils are more likely to respond to 

 potassic manuring than others better supplied with water but no 

 richer in available potash." The same applies to phosphoric acid — 

 " Little, if any, direct connexion can be traced between the phos- 

 phoric acid and the productiveness." 



As far as regards the value of soil-analysis as a basis 

 on which to afford advice as to soil-treatment, I have no 

 reason to alter the opinion expressed in a paper read be- 

 fore this Association on "Soil Analysis" in Brisbane, 1895 



X 2 



