172 Irrigation and Drainage 



important to supplement the rainfall under wholly 

 normal field conditions, to see if there would then be 

 any notable increase over the yields produced under 

 the natural field conditions. This led to a series of 

 experiments to be conducted parallel with those on till- 

 age, to learn how far short of possible yields our actual 

 ones are when secured under the best moisture relations 

 at our command ; and irrigation experiments as checks 

 on our tillage experiments were begun, the results of 

 which it is important to state. 



In conducting these control experiments on irriga- 

 tion, the aim has been to treat the crop growing under 

 the conditions of the normal rainfall and under those 

 of the rainfall supplemented by irrigation, exactly 

 alike in every way until it became apparent that more 

 water might be used with advantage, when water was 

 applied to the control plots as often as it seemed de- 

 sirable. No other elements of difference have been 

 introduced than those growing out of applying the 

 additional water. 



IMPORTANCE OF THE AMOUNT AND DISTRIBUTION OF 



WATER IN POTATO CULTURE, AND THE ADVANTAGE 



OF IRRIGATION IN CLIMATES LIKE WISCONSIN 



There have been two seasons' work with this crop, 1896 and 

 1897, and both years the potatoes have been planted in rows 30 

 inches apart and in hills 15 inches in the row, or else twice that 

 distance. The ground in each case was given a good dressing of 

 farmyard manure, plowed in 6 inches deep. Large tubers were 

 used for seed, cut two eyes to the piece, and planted with hoe 

 about 3 inches deep, and the ground harrowed after planting. 



