Water Used bij Plants 27 



soil enriched with farmyard manure, to determine if a rich soil 

 affected in any notable way the rate at which water was used in 

 crop production. 



The results of these trials may be stated as given below: 



/ Flint corn * / Flint corn 



Manured Not man'd Manured Not inan'd 



1234 

 LBS. LBS. LBS. LBS. 



Dry matter per acre 34,730 33,620 22,540 9,505 



Water used per Ib. of dry matter 223.3 232 257.4 223 



Water expressed in inches 34.23 34.42 25.56 13.06 



The difference in yield between cylinders 3 and 4 and 1 and 2 

 appears to have been due to the condition of the soil at the time 

 the cylinders were fitted, the soil being more moist in 3 and 4, 

 which stood upon ground lower and too wet for conditions of best 

 growth. The field yield of corn surrounding the cylinders, and 

 with the same kind of soil, was 4.4 tons of dry matter, yielding 

 66.95 bushels of kiln-dried shelled corn per acre, which is large 

 for field conditions with the normal rainfall. But the mean yield 

 in cylinders 1 and 2 was 17.09 tons of dry matter per acre, or 

 almost four times as much, while the average of the four cylinders 

 was 2.85 times as large, but using 2.2 times the amount of water 

 which fell upon the surrounding fields as rain during the growing 

 season for this corn. 



It does not, of course, follow from these experiments that well 

 tilled field soil, if irrigated properly, will produce such yields as 

 these which have been recorded ; neither does it follow, neces- 

 sarily, that these large yields owe their excess over normal crops 

 only to the extra supply of water added at the proper times. 

 It does, however, follow from these experiments, we think, that 

 were our water supply under better control and larger at certain 

 times than it is in Wisconsin, our field yields would be much 

 increased, if not actually doubled. It does follow, also, from 

 these experiments, that well drained lands in Wisconsin and in 

 other countries having similar climatic conditions are not supplied 

 naturally with as much water during the growing season as most 



