REPORT OF THE CHEMIST. 



161 



In nitrogen and organic matter this soil ranks very high, and, though not as rich 

 in total potash and phosphoric acid as many of our virgin soils, it is by no means 

 deficient in these important constituents. 



Soils Ros. 2 and 3. — Represent the soil immediately beneath the preceding sample 

 at the depth of 12 to 18 inches and 18 to 24 inches respectively. In physical appear- 

 ance and condition, as well as in composition. No. 2 is very similar to sample No. 1 ; 

 showing that the surface soil has practically a depth of 18 inches. While, as might be 

 expected, the lower sample (No. 3) is considerably poorer in organic matter and nitrogen, 

 the percentages of potash and phosphoric acid are identical with those in the overlying 

 soil. It is of a yellowish-gray colour with streaks of black soil throughout its mass. 

 It will be seen to be of excellent quality for a sub-soil. 



It. will be interesting now to consider the proportions or percentages of these 

 elements that may be looked upon as more or less immediately available for plant use, 

 i. e., the amounts extracted by the 1 per cent citric acid solution before referred to. 



TABLE II. 

 Comparison of " Available " with " Total " Amounts of Potash and Phosphoric Acid. 



In speaking of minimum limits of available plant food. Dr. Dyer says : — " From a 

 careful consideration of the whole of the results, it would perhaps not be unreasonable 

 to suggest that, when a soil is found to contain as little as about 0-01 per cent of 

 phosphoric acid soluble in a 1 per cent solution of citric acid, it would be justifiable to 

 assume that it stands in immediate need of phosphatic manure." 



In potash he obtained results that led him to consider that an application of special 

 potash fertilizers would prove valuable when the soluble potash fell below 005 per cent. 



In available mineral plant food the surface soil now under consideration is seen to 

 give results approximating these limits. The estimations above tabulated are, however, 

 more particularly useful in showing that the upper or surface portions of the soil contain 

 much larger amounts of available food than the underlying soil. We are thus furnished 

 with data to support the view that the greater productiveness of a surface soil, compared 

 with its sub-soil, apart from the presence of nitrogen, is due in large part to the 

 availability rather than to the total amounts of mineral fertilizing constituents present. 



Soil No. j^ — From Alberni, Island of Vancouver ; a clay loam of a deep red colour 

 which masks entirely the presence of the large amount of organic matter present. This 

 sample is said to represent the soil to a depth of 9 inches over an approximate area of 

 10,000 acres. The sub-soil of this area is variable, sometimes clay, sometimes gravel 

 and sand. In potash this soil is comparatively rich ; in phosphoric acid, however, it is 

 much below the average. As regards nitrogen it is of medium quality. 

 8a— 11 



