REPORT OF THE CHEMIST. I40 



SESSIONAL PAPER No. 16 



soils have given numbers far larger, but these may fairly represent the limits exhibited 

 by soils of good, medium quality. The amounts of potash, phosphoric acid and lime 

 designated in the table as available are those obtained by digesting the soil with a one 

 per cent solution of citric acid in the cold. English results seem to justify the 

 assumption that less than '01 per cent of phosphoric acid, so obtained, indicates the 

 soil's need of phosphatic manure. With regard to the available potash. Dr. Dyer, who 

 sliowed that the acidity of root sap was approximately equal to the afore-mentioned 

 solvent, says that when such potash falls below '005 per cent, potash fertilizers would 

 prove valuable. Judged by these standards, we are obliged to confess this soil as con- 

 siderably below the average in all its important elements, save perhaps in available 

 potash. 



Humus and Nitrogen. — It is extremely doubtful if commercial fertilizers could 

 be used profitably on this soil unless supplemented, or rather preceded, by organic 

 manures. When the store of humus has been increased, the soil will be more retentive 

 of and responsive to such plant-food as may be supplied in chemical fertilizers, and 

 further it will be warmer and furnish a more comfortable medium for seed germina- 

 tion and root extension. Barnyard manure, naturally, stands first in importance as a 

 Bource of soil humus ; it would be difficult to overestimate the value of this manure for 

 soils such as we are discussing. Not only for its organic matter, is it to be recom- 

 mended; as a supplier of nitrogen and a considerable amount of mineral matter in 

 a more or less available condition, it has a distinct value. 



Unfortunately, in the majority of cases, especially where there is a considerable 

 area tilled, there is not a sufficiency of manure, and it then becomes of the highest 

 importance to know what can be most economically used as a substitute. Where 

 swamp muck occurs, this material may be utilized, first being piled and allowed to 

 dry out and then fermented as in the compost heap, either with manure or with lime 

 or wood ashes. The air-dried muck may be employed as an absorbent in the cow 

 stable, pig-pen, &c., to absorb the liquid manure. In this way a double purpose is 

 served — the valuable liquid portion of the manure, which might otherwise be lost, is 

 retained, and the fertilizing elements in the muck set free. Good samples of air- 

 dried muck will contain from 6.5 per cent to 85 per cent organic matter, and from 

 1'25 to 2'5 nitrogen. 



Possibly the only feasible plan of furnishing humus and nitrogen over large 

 areas is by the turning under of a growing crop of clover or some other legume. This 

 is termed green manuring, and is certainly to be regarded as the most economical 

 and one of the quickest methods of replenishing the soil's humus. The benefits to be 

 derived from green manuring, especially when a legume is used, have so repeatedly 

 been set forth in our past reports that it may not be necessary to speak at any length 

 on that subject. It is well to emphasize, however, in this connection, three points : 

 first, if the soil is too poor to grow clover, buckwheat or rye, may be ploughed under 

 for a year or two and the land thus made suitable for clover; secondly, that a dressing of 

 wood ashes or a fertilizer containing potash and phosphoric acid will very much help 

 the clover, and, thirdly, there will be no practical enrichment of the soil with nitro- 

 gen, unless a legume is used, since the legumes only have the ability (by the means 

 of certain germs that reside in nodules on their roots) to appropriate and store up 

 the free nitrogen of the air. 



Lime. — The analytical data show that this soil is by no means rich in lime, and 

 its well marked acidity accentuates this fact. The land evidently stands in need of 

 lime, not only as a source of plant food, but to correct that sourness which is injurious 

 to most farm crops. Since it is not wise to make heavy applications of lime, and 

 since this element has the tendency to work or wash down into the subsoil out of 

 the reach of the roots, the application of, say, 20 bushels per acre every second or 

 third year, will prove better practice than a larger dressing at greater intervals. If 

 phosphoric acid is applied in the form of Basic slag, mucli less lime than that indi- 



