Productive Capacity of Different Crops 261 



application is possible. Of course, other things out- 

 side of .quantitj' of production are not generally equal. 

 The cost of production varies so that the largest j ield- 

 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 : 



Drj' Digestible 



* Yield Dry mat- dry 



per acre matter ter matter 



fresh ma- Dry per digesti- per 



terial matter acre ble acre 



lbs. i lbs. i lbs. 



Alfalfa 35,000 25 8,750 69 5,162 



Maize, whole plant 30,000 25 7,500 61 5,025 



Red clover, about 33^ tons new hay.. 18,000 30 5,400 57 3,070 



Oats and peas 20,000 16.2 3,240 65 2,106 



Timothy, about 2% tons new hay 11,500 38.4 4,416 57 2,517 



Hungarian grass 19,000 25 4,750 67 3,182 



Mangolds 60,000 10 6,000 88 5,200 



Sugar beets 32,000 20 6,400 88 5,632 



Potatoes 18,000 25 4,500 85 3,825 



The estimates here given may not coincide with the 

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



