34 



T. Lyttleton Lyon and James A. Bizzell 



the soil received in being transferred to the lysimeters, altho it was not 

 allowed to become air-dry, which always greatly increases the quantity 

 of soluble plant nutrients in a soil. The average yields of crops on 

 these tanks for each of the years of the experiment are given in table 15. 

 The yield for each tank is given in table 1 of the appendix (page 92). 

 If moisture were a limiting factor in the production of these crops, 

 it may be assumed that the fact would be indicated by a diminished 

 flow of drainage water from the tanks producing the largest crops. This 



720- 

 700- 



^ 660-\ 

 \ (b^O- 





(bZO- 

 600- 

 580- 



^ 560- 

 ^ 540- 

 ^ 520- 

 $ 500- 



vi 'fao- 



£?ra/nage 



Y/e/ds of c/ry maf/er 



I 



I 



t 



t'i 



■2.511: 



TcfnA 3 Tank 5 lank 7 lanM 9 



Tc7nk// Tcfnk/2 



CI 



Fig. 6. total flow of drainage water from certain tanks for the year 

 beginning may 1, 1910, and yield of maize on the same tanks in 1910 



The percolation bears no direct relation to the crop jdeld 



could be shown by a line plotting the yields and one plotting the flow 

 of drainage water, in which the greatest yields should correspond to 

 the least drainage. In figure 6 are shown the yields of dry matter in 

 the maize crops on tanks 3, 5, 7, 9, 11, and 12 in 1910, and also the 

 quantities of drainage water in liters from the same tanks for the period 

 beginning May 1, 1910, and ending April 30, 1911, when the moisture 

 content of each tank would have returned to its capillary capacity. In 

 figure 7 are shown the total yields of dry matter in the five crops raised 

 on each of tanks 3, 5, 7, 9, 11, and 12, and also the quantities of drainage 



34 



