n6 FARM AND SCHOOL PROBLEMS. 



2. Thirteen experiment stations made over 60 tests to determine the 

 difference between deep and shallow cultivation, and the result was 

 a gain on an average of 9.8 bushels more per acre of shallow cultiva- 

 tion over deep culture. If the average yield by shallow cultivation 

 was 60 bushels per acre, what was the gain per cent.? 



FIG. 7. Distribution of corn roots, showing how late deep cultivation 



affects the roots. 



Shrinkage in Corn. 



Experiments covering periods of from one to eight years 

 carried on in different states showed that the average shrinkage in 

 these instances was about 3 per cent from November to February 

 ist, 5 per cent for the first six months, and about 9 per cent for a 

 period of one year. But experiments made in Ohio, Illinois, Iowa 

 and in Kansas show that it is impossible to compute an average 

 shrinkage or to determine what the variation in price should be 

 in order to fix a price that will balance the losses caused by stor- 

 age for a fixed period of time. There is a constant variation in 

 the moisture content depending upon the variation of the sea- 

 sons, so that the only fair way to determine the price is to use 

 the artificial test. 



