92 EXPERIMENTAL FABMS 



5 GEORGE v., A. 1915 



of this type, cultivation leads to the dissipation of organic matter and, therefore, for 

 the maintenance of fertility it will be essential to supply continually humus-forming 

 material as with farm manures and the turning under of green crops. By this means 

 the soil may be made more retentive of moisture and of such plant fool as may be 

 supplied in the form of commercial fertilizers. 



If the water table is not too high, this soil would readily drain, allowing an easy 

 and complete aeration. This soil should rapidly warm up in spring and respond well 

 in favourable seasons to high manuring. It is not, from the physical standpoint, to be 

 considered a good general farming soil, but it has characters which make it suitable 

 for some crops, prominent among which we might place potatoes, and similar garden 

 crops. 



Lahy. No. 8759. — This soil differs essentially from the preceding in its smaller 

 percentages of gravel and very coarse sand and its much larger proportion of silt and 

 clay. Though it might be characterized as a clay loam, it contains sufficient coarse 

 material to make it friable and to permit of it being easily worked. From the physical 

 standpoint the exceedingly small organic content is its most unfavourable feature, and 

 it is undoubtedly in the addition of humus-forming material tliat improvement, iirst 

 as to tilth and then ' life ' of the soil, is to be chiefly looked for. 



Lahy. No. 8700. — This is a clay or heavy clay loam. With good drainage and 

 careful, rational tillage it should prove a strong, productive soil. With an increased 

 organic matter content, the probability is that the texture would be considerably 

 improved, and hence the desirability of stable manures and the adoption of a rota- 

 tion which would from time to time add to the soil's store of humus. Besides its 

 valuable influence on the texture, humus may always be considered as an economical 

 source of plant food. 



Lahy. No. 8761. — This is a gravelly, loam, but probably contains sufficient silt 

 and clay to give it ' strength ' and make it fairly retentive of moisture. From the 

 viewpoint of texture it should prove very fairly satisfactory for a large range of 

 crops, but the value of organic matter as an amendment, as well as for the purpose 

 of enrichment, may, as in the preceding instance, be again emphasized. 



The composition of the soils as revealed by chemical analysis is set forth in the 

 following table. In addition to the amounts of the essential mineral elements of 

 plant food (phosphoric acid, potash and lime) obtained by the use of a strong acid 

 solvent, the percentages of these constituents soluble in a dilute solution of an 

 organic acid have been obtained. These latter may be regarded as representing more 

 or less closely the proportions available for crop use, and hence in a certain degree 

 may serve to indicate the need or non-need of specific fertilizers. 



In considering these analytical data with the view of deducing the relative 

 fertility of the soils, it must not be lost sight of that it is impossible to establish 

 rigid standards as regards the minimum amounts of plant food that must be present 

 in order that a soil may be classed as economically productive. Again, it nuist be 

 borne in mind that the climatic conditions of the district, the drainage and the 

 texture of the soil, play a most important part in maintaining fertility. Further, 

 the amount of humus-forming material and its condition are potent factors, not only 

 in determining the water-holding capacity of a soil, but also in affording nourishment 

 for the micro-organisms of the soil, the role of which is largely to prepare the plant 

 food constituents for the use of farm crops. Especially is this true as regards nitri- 

 fication — probably the most important of all the conversions into available forms 

 within the soil. These matters, here so briefly discussed, will be found more fiilly 

 considered in the Keport of the Chemist, Experimental Farms, 1S97, but possibly 

 sufficient has been said to show that percentages of the more important elements, 

 useful as they are, must not be taken as the sole guide in the valuation of a soil. Its 



