Lysimeter Experiments 



35 



water from each of these tanks for the five-years period beginning May 1, 

 1910, and ending April 30, 1915. 



Neither of these diagrams indicates that there is a definite relation 

 between the yield of crop and the quantity of drainage water from any 

 tank. Apparently the moisture supply was adequate to produce as 

 large crops as the other factors would allow. This shows strikingly 

 the possibilities of storing moisture in a well-drained clay loam soil, and 

 raises the question whether, with a normal rainfall in this climate and 



^ 



^ 3900- 

 >5 J800- 

 I 3700- 

 r^36O0- 

 ^ 3500- 



\ J300-\ 

 ^ 32C?0 

 < 3IOO- 

 \X3000- 

 \Z9O0- 



i 



Y/e/c/s of dri^ maffer 



U-^ 



Tcfn/O TcfrrkS Tc/r7k7 Tank 9 Tan/r// Tank/Z 



^ \ 



-6./ 5 

 -<>.o%. 



-5.9^ 

 -5.31 

 -5.7% 



5.6 I 

 -5.5\ 

 -5.^\ 

 -5.31 

 -5.2 § 

 -5./0 



5.o\ 

 \ 



Fig. 7. total flow of drainage watkr from certain tanks for five tears, 

 and yields of crops on the same tanks for those years 



The percolation bears no direct relation to the crop yield 



where drainage may be obtained, moisture need ever be a limiting factor 

 in loam soils. 



A comparison of the yields of crops on the tanks in 1910, and for the 

 same year on the corresponding field plats — which latter had no artificial 

 drainage but received the same fertilization and produced the same kind 

 of crops as the tanks — shows a much larger yield from the tanks. To 

 what extent this is due to the thoro aeration to which the tank soils are 

 subject, and how much is due to the moisture supply, it is impossible 

 to say. The comparison is recorded in table 16: 



35 



