60 T. LytTTLETON LYON AND JAMES A. BizZELL 
TABLE 10. RELATION OF TRANSPIRATION Ratios, ToTat Sotips In Dratnace WATER, 
AND Crop YIELDS 
Total solids Crop 
Minimum | Evapo- | in drainage yields in 
trans- trans- of un- 1915-1917 
piration piration |planted tanks (grams 
ratio ratio (parts per per 
million) tank) 
Wolusiaysiltsloamsasseee eer ee Se 1:451 1:908 297 .7 3,359.0 
Munkarkiclaysloameess eer eee ee 1: 290 1:580 401.5 6,478.3 | 
It would appear from the data presented in table 10 that an economic — 
utilization of water by the plant accompanies a high concentration of the | 
water passing thru the soil, and that there is, moreover, a relation between 
the concentration of this water and the productive ability of the soil. 
Moisture relations of crops 
In table 11 is given a statement of the moisture relation of each 
crop grown on these tanks during the five years of the experiment. The 
TABLE 11. Moisture Rewations oF Crops on Tanks 13 AND 15 DURING THE PERIOD 
FROM 1913 To 1917 
Trans- 
irati D Rainfall 
Minimum | Evapo- ere iene in 
Year Tanks Crop trans- Gees evapo- in crops | percolate | 
piration Pees ration (pounds (per 
ratio (acre per acre) cent) 
inches) 
LOTS eel ose ee eOatse see 1:373 | 1:690 10.13 3,542 
1 OAs 13, 15..| Canada 1:525 | 1:1005 14.08 3,316 
peas 
1915 eee 13, 15..| Maize 133325) 4 1613 12.68 4,977 64.49 9 
1OTG see ee S15 ee Oaterease 1:366 | 1:1108 11.85 2,546 54.75 
LOVES. 13, 15..| Barley 1755) |e 61S 13.06 1,858 69.80) 
Wt Eee 
minimum transpiration ratios for all these plants are highef than fort 
the same plants grown on the Dunkirk soil, and the evapo-transpiration | 
ratios also are higher. These discrepancies emphasize the futility of - 
trying to determine a standard for the water requirements of plants when } 
soil is used as the medium in which the plants are grown, 
f 
