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these features the producer has several advantages. He can often 

 choose between different kinds of product into which he can convert 

 his timber. He can postpone harvesting his crop in times of depres- 

 sion and put it on the market when prices are high. He can produce 

 different quantities of products of different classes by postponing or 

 withholding harvesting of a portion of his stand, or selected trees. In 

 addition, he can greatly modify or increase the value of his crop by 

 selection of species for harvesting, taking out the more worthless for 

 fire wood and reserving the more valuable for higher uses. When 

 creating a new forest by planting he can exercise choice of species, just 

 as a farmer can decide as to what he shall plant, and, like the farmer, 

 his success will depend on his ability to select the crop which is adapted 

 to the soil and site, and not merely on his skill in planting trees or 

 potatoes. 



The relative productiveness of different forest soils can be judged 

 by the volume measured in cubic feet of wood produced annually. To 

 obtain this figure is not an easy process unless the wood crop on the 

 area is all of the same age, otherwise it can not be known whether the 

 amount cut from the lot represents the growth of a definite period or 

 is merely the accumulation of an indefinite number of years. Again, 

 wood crops must be measured for volume production when thev have 

 attained a reasonable maturity, else the average annual production is 

 not fairly realized. Potato crops, measured when half grown, do not 

 show full production. But all field crops reach definite ripeness while 

 with woods crops this period is comparative only, and the measurement 

 of many different stands is necessary to determine the approximate 

 period of highest average annual crop-yields, and those of greatest pro- 

 dttction of money income. 



This study will be undertaken in Illinois during the years 1924 and 

 1925. Meanwhile preliminary figures show that an acre of soil grown 

 to hardwoods will produce annually from 16 to 160 cubic feet of wood. 

 The production of wood, as may be expected, is in direct ratio to the 

 fertility of the site. This is illustrated by the following samples. 



Extremely dry sandy hills may yield less hardwoods per acre than 

 the lowest yields which are recorded. If planted to suitable conifers, the 

 apparent yields may be doubled, yet when weight is considered may not 

 exceed greatly that of hardwoods. The maximum yields on any site 

 can only be secured by the growing of species, best adapted to tliis 

 site and to the condition of the land at the time. When land is bare 



