Investigations at Lincoln, Nebraska. 39 



that greatly increased their absorbing area. This was especially marked 

 in the case of corn and potatoes. 



The more superficial roots reached their maximum development first. In 

 most cases this occurred about the time the top had reached an intermediate 

 stage of growth; the deeper roots developed coordinately with the top and 

 thus balanced water absorption and transpiration. 



Oats reduced the soil moisture to a greater degree than any of the other 

 small cereals. Corn in its later stages of growth was an extravagant user of 

 water. The potato showed the greatest variation in the number and extent 

 of its roots. 



The root systems of isolated crop plants are greatly modified as to nature 

 and extent when compared with similar plants grown under the competi- 

 tive conditions imposed by the rate of planting in ordinary field practice. 



The season in which this investigation was carried on had a deficit of rain- 

 fall, particularly during the months of May, July, and August. The defi- 

 ciency was sufficient to mark it as a dry crop-year. 



