REPORT OF TEE CHEMIST 165 



StbSIUNAL PAFEn No. 16 



WHEAT AND BARLEY. 



THE COMPOSITION OF THE GRAIN AS INFLUENCED BY THE SOIL MOISTURE-CONTENT. 



This investigation, now in the sixth year of its progress, was continued during 

 the past season on the Experimental Station at Lethbridge, Southern Alberta, growing 

 wheat and barley under ' dry farming ' conditions and under irrigation. In addition to 

 the analysis of the parent seed and of the crop, determinations of the soil moisture- 

 content of the several plots have been made at intervals throughout the season. It was 

 expected from the data so obtained to find a relationship between the moisture-content 

 of the soil during the vegetative period and the protein-content of the grain, for pre- 

 vious work had shown that the latter is always higher when development is hastened 

 by a scanty supply of moisture and high temperatures than when ripening is retarded 

 by ample moisture and cool weather. 



n heat. — The moisture-content of the irrigated and non-irrigated areas, as deter- 

 mined several times during the season, to a depth of fourteen inches, may be stated 

 as follows : — 



Moisture-content of Wheat Plots. 



Date. 



May 25, 1910 '. 



June 21, 1910 



July 4, 1910 



July 10, 1910 



July 18, 1910 



August 1, 1910 



The plots used in this investigation, on the irrigated and non-irrigated areas alike, 

 had been summer-fallowed in 1909, so that we might expect but slight differences, if 

 any, in their moisture-content at the opening of the season, 1910. That such is the 

 case will be seen from the data for May 25. A month later (June 21), the moisture- 

 content on both areas, though considerably reduced, was still practically identical. 

 Since the seed was sown on April 1, it is evident that the environment, in so far as 

 soil-moisture is concerned, had been the same for the wheat on both areas during the 

 major period of its growth. And, further, this period was an exceedingly dry one, 

 certainly the driest since reliable meteorological observations have been recorded at 

 Lethbridge. 



Immediately after the collection of the second set of samples, the first irrigation 

 was made (June 22), and the third series was not taken till a fortnight later (July 4), 

 when the irrigated plots contained approximate^ 7 twice the amount of moisture pres- 

 ent in the non-irrigated area. The percentage of moisture in the latter was practi- 

 cally the same as on June 21. On July 10, the moisture was decidedly low on both 

 areas, though there was a difference of 2 per cent in favour of the irrigated land. 



The second irrigation was on July 13, and the fifth collection of samples was made 

 five days later, July 18. We find moisture conditions very similar to those of July 4 — 

 a very low moisture-content in the soil of the non-irrigated area with approximately 

 twice the amount in the irrigated soil.- The sixth and last collection was on August 1, 

 when the crop on both areas was harvested. Again, we find the soil very dry; in 

 the non-irrigated land there was but 5 -22 per cent, while in the irrigated area the soil 

 ridy contained 8-19 per cent. 



Our conclusions from these data may. be summed up as follows : (1) That both 

 plots started with practically the same moisture-content, a very fair but not exces- 



