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liliroliT OF THE CHEMIST 153 



SESSIONAL PAPER No. 16 



Plot A was left undisturbed and the soil was soon fully occupied by weeds. Tlicse 

 were cut, but not closely, on August 24 to prevent seeding. The first moisture deter- 

 mination (July IS) showed that the growth of the weeds had very markedly dried 

 out the soil, though not to the same extent as the sod in Plot 1, Series I. Compared 

 with Plot B, adjoining and which was kept cultivated, it contained at this date 16G 

 ton.s loss water per acre, calculated to a depth of 14 inches. 



Two weeks later (August 1) the moisture content was somewhat higher — about 

 nine-tenths of a per cent, but this increase was undoubtedly due to the rainfall 

 (approximately -7 in.) two days previous to the collection of the sample. On August 

 15 the percentage of water had fallen to a point lower than at any previous date, viz. 

 <5-T0 per cent. The soil taken on August 29 showed 10-20 per cent water. This in- 

 crease is explained by the fact that the weeds were now functionally inactive, practi- 

 cally dead, and that during the preceding nine days rain had fallen to a depth of \\ 

 inches. 



The dryness of the soil on September 9 and 27 is significant (6-07 per cent and 

 7 -30 per cent respectively). The weeds were not now making any great demand on the 

 soil's moisture, but nevertheless a loss of water was taking place. This was a result 

 of the undisturbed capillarity and surface evaporation — which, as we have before 

 remarked, may be as potent a factor in the loss of water as a growing crop. 



Plot B affords some interesting and instructive results. It was kept cultivated till 

 -Tuly 30. when it was seeded to rape. Its moisture content remained constant (ap- 

 ])roximatcly 14 per cent) so long as it was cultivated, but as soon as the rape attained 

 a fair growth it began to exhaust notably the soil's store of water. This and sui'face 

 evaporation reduced the moisture content to amounts practically identical with those 

 of Plot A. as determined on the two last dates of the investigation. This furnishes 

 evidence as to the value of rape as a cover crop when it is desired to dry out the soil 

 and then hasten the ripening of the wood of the trees before winter sets in. 



Plot H. — This was cultivated until August 1, but unlike Plot B, bore no crop 

 subsequently. The first sample was taken for analysis on August 29 as the data com- 

 pared with those of Plot B would show what loss in the latter had ensued from sowing 

 the rape. Although the rainfall from this date till the close of the investigation was 

 light, this plot held its own, or practically so, the percentage of water being between 

 13 and 14. The deduction from these results is that if it is desired to dry out the soil 

 to any considerable degree it is necessary to sow a cover crop. It will be noticed that 

 it contained 150 tons more water per acre than Plot B. But yet both plots had 

 received exactly the same amount of cultivation and on the same dates. The differ- 

 ence therefore must have been owing to Plot B carrying the crop of rape while Plot 

 II had been free of vegetation. 



PRELIMINARY REPORT ON SURFACE SOILS FROM THE ABITIBI 



REGION.* 



This series of soils, comprising thirteen samples, was forwarded to the labora- 

 tories of the Experimental Farms, Ottawa, during the first half of the year 1005. 

 The dates of their reception and the localities from which they were collected are 

 given in the subjoined table, which also presents the analytical data obtained. The 

 soils are arranged in the order in v/hich they were received, 



A brief description of the soils from a preliminary examination, chiefly physical 

 and microscopical, may be given as follows: — 



1. Yellowish white clay, with very little sand, and practically destitute of organic 

 matter. Reaction: very slightly acid. Traces of lime. 



2. Greyish-white clay, with fair amount of coarse sand and some pebbles. A" 

 little root fibre. Reaction : slightly acid. Traces only of lime. 



* CoHcctcJ and forwarded by Mr. Frank Moberly, C.E., of the engineering staff of the 

 Transconiiuental Railway. 



