294 



EXPERIMENT STATION RECORD. 



made with potatoes and oats. The i><>tatoes were yrowu in 8 <;'alvan- 

 ized iron cylinders 18 in. in diameter and 42 in. deep, 2 of which were 

 sunk flush with the ground in the open fiehl and the otliers stood 

 above ground where they coukl be sheltered. The experiments differed 

 from previous ones in the method of aiiplying water and in not allowing 

 any rain to fall upon the i)ots. 



"The iiietliod of watering adopted was to set up within each cylinder a column of 

 3-inch drain tile close against one side and to add water liy pouring it into this tube 

 from time to time as needed, talcing care always to add no larger quantity at a time 

 than would raise the water in the tile 6 in. ahove the hottom. All the water these 

 potatoes received was therefore procured through capillarity and root action from a 

 dei)th equal to or exceeding 3 ft." 



The results obtained in these experiments were as follows: 

 Amounts of wafer used by the potato. 



No. 1 

 No. 2 

 No. 1 

 No. 2 

 No. 3 

 No. 4 

 No. 5 

 No. 6 



Dry matter ^aterused 

 i./r oTiin '**' pound 

 ''^^- ter. 



Pound. 

 0.5130 

 .5258 

 . 3338 

 .5007 

 .4505 

 .5020 

 .3596 

 .5425 



Pounds. 

 430. 4 

 415.0 

 586.9 

 480 9 

 510.8 

 472.1 

 497.3 

 458.4 



Dry matter 

 per acre. 



Pounds. 

 12, 650 

 12, 960 

 8,248 



12, 340 

 11,110 

 12,370 



8,865 



13, 370 



Total water 

 used. 



Inches. 

 24.02 

 23.74 

 21.31 

 26.20 

 25.33 

 25.78 

 23. 37 

 27.06 



Acre-iuclies 

 of ^yat(■r 

 per ton of 



dry matter. 



Inches. 

 3.80 

 3.66 

 5.17 

 4.25 

 4.56 

 4.17 

 5.27 

 4.05 



The potatoes were injured by blight, and for this reason the produc- 

 tion of dry matter was not as high as it otherwise would have been, 

 but— 



" It is evi<lent enough from the table, whatever may be said regarding the yields 

 of dry matter, that the potatoes did use a a ery large amount of water, in fact a 

 quantity 3 times the amount of the rain which fell during their period of growth, 

 and since the surl'ace of the ground was kept dry through the whole season Acry 

 much the larger proportion of the water must have passed through the vines and 

 only a small jiart could have been lost through the soil directly." 



Experiments of this kind have been made on oats grown in cylinders 

 sunk in the ground during 3 years with the following results: 



