response and, at times, sustained high flow 

 example, is flooded from early June through 

 other factors such as the amount of vegetat 

 plant conditions, stage of growth, soil con 

 other factors have been known to affect the 

 effluent discharged, irrigation intensity w 

 most important single factor. Table 12 pre 

 average tile discharge for various crops in 

 Several tile systems are represented for ea 



s. Rice, for 



August. Although 

 ive ground cover, 

 ditions, and 



amount of 

 as considered the 

 sents the annual 



1959-63 and 1967. 

 ch crop shown. 



TABLE 12 



COMPARISON OP 

 TILE DRAIN DISCHARGE BY VARIOUS CROPS 

 (in acre-feet per acre) 



The kind of crop does not always dictate the quantity of 

 tile drainage. Several other tile systems (not shown in 

 Table 12) draining diversified row crops within the study 

 area discharged more per year than did the systems from 

 tiled rice fields. 





Influence of Crops on Nitrogen Concentrations 



Rice was the only crop that exerted an appreciable influence 

 on nitrogen concentrations observed in tile drainage systems, 

 The decreased nitrogen concentrations noted in effluent 



5^ 



