io6 



READINGS IN RURAL ECONOMICS 



Table 4 shows the comparative yields of corn, wheat, oats, bar- 

 ley, rye, buckwheat, potatoes, and hay, for every year since 1 866. 

 Each crop was compared with its 1866 yield as 100 per cent. 

 These percentages were then averaged in order to get the per- 

 centage yield for each year. If one crop had more acreage than 

 another, it is given proportionately more weight in determining 

 the average. The figures are what is known as a weighted aver- 

 age. ^ This is the fairest possible way of comparing the yield* of 

 different acres, since it gives every acre equal weight. 



The chart on page 107 shows the comparative yields for states 

 east of the Mississippi River. This curve shows a period of general 

 low production during the eighties and the early nineties. During 

 that period prices were low and farmers were having hard times. 

 Since 1896 the yields in these states have only once dropped 

 below the 1866 crop; that was in the very dry year of 1901, 

 Never before have the eastern states shown such high yields as 

 in the last eight years considered. In four of these years the 

 crops have been better than ever before produced. In every year 

 the crops have been good, 



********** 



W/iy are crop yields increasing f The writer does not believe 

 that changes in crop yields can be taken as a measure of soil 



1 The method of calculating the comparative crop yieMs, or the crop index, is 

 best shown by an example : 



Acres Grown 

 IN 1912 



Comparative 



Yield per Acre 



(1866 yield as 



100 per cent) 



Acres 



multiplied bv 



Percentage 



Yield 



Com . . , 



Wheat , . 



Oats , . . 



Barley . 



Rye . . . 

 Buckwheat . 

 Potatoes 



Hay . . . 



Total , 



107,083,000 



45,814,000 



37,917,000 



7,530,000 



2,117,000 



841,000 



3,711,000 



49,530,000 



115 

 161 

 124 



130 

 124 

 105 



113 

 120 



254.543,000 



123,145,450 



73.760,540 



47,017,080 



9,789,000 



2,625,080 



883,050 



4,193.430 



59,436,000 



320,849,630 

 Percentage yield, or crop index = = 126 per cent 



254,543.000 



320,849,630 



