Water Used by Plants 33 



permit a single watering every seven days to meet the needs of 

 the plants. 



The results of the two years are given in the following table: 



i 

 BU. 



Field per acre, 1896 513.5 



" 1895 74 



Difference 449.5 



IN. IN. IN. IN. IN. IN. 



Inches of water used, 1896 . . 25.85 27.91 29.07 34.08 32.63 27.51 



' 1895.. 10.76 2002 17.65 1627 20.65 12.96 



Difference 15.09 7.89 11.42 17.81 11.98 14.55 



It will be seen from this table that both the yield of potatoes 

 and the amount of water used are much larger in 1896 than they 

 are in 1895, the average yield in 1896 being 878.1 and in 1895 

 only 275.8 bushels, the former being 3.18 times the latter. The 

 average amount of water used was 29.51 inches in 1896, and 16.385 

 inches in 1895, the former being 1.8 times the latter. 



As a further check upon these experiments, two cylinders 7 

 feet deep and 4.33 feet in diameter were filled with a local yellow 

 sand, and to one of the cylinders farmyard manure was applied 

 at the rate of 50 tons per acre, and to the other at the rate of 25 

 tons per acre. These were planted in 1895 with Alexander Pro- 

 lific potatoes, seven pieces in each cylinder. The watering in 

 1895 was once each week, and twice each week in 1896. In the 

 latter year no fertilizers of any kind were applied, and Eural 

 New-Yorker potatoes were planted instead of the Alexander Pro- 

 lific. In 1895, 20.05 inches of water gave a yield of 605.5 bushels 

 on the heavily manured cylinder and 563.5 bushels per acre on 

 the other. But in 1896, when the potatoes were watered twice 

 eac/h week at the rate of 75 pounds for the lightly manured case 

 and 50 pounds for the other, the yield per acre on the lightly 

 manured cylinder was only 312 bushels, and yet 40.61 inches of 

 water were used; while the other cylinder gave a yield of 344.5 

 bushels per acre and used 31.92 inches of water. 



