Productive Capacity of Different Crops 261 



application is possible. Of course, other things out- 

 side of quantity of production are not generally equal. 

 The cost of production varies so that the largest yield- 

 ing crop is not necessarily the most economical. This 

 is a local matter also, concerning which no safe gen- 

 eral statement can be made. It would be convenient 

 if some correct, universal standards of production and 

 cost could be formulated for the guidance of farmers, 

 but both growth and cost are much modified by lo- 

 cality and other circumstances, and data are not avail- 

 able, and doubtless never will be, from which useful 

 averages may be obtained. 



The most that it is possible to show is the rela- 

 tive productive capacity of different crops when the 

 yield is what is regarded as highly satisfactory in fa- 

 vorable localities under good culture. This is done in 

 the accompanying table. Attention is again called 

 to the fact that judgment should be based upon the 

 amount of digestible dry matter produced : 



The estimates here given may not coincide with the 

 views of all as to what constitutes a fair crop, but 



