FARM MANAGEMENT PRACTICE OF CHESTER COUNTY, PA. 175 
proper limits they make more profit by this procedure. The figures 
of Table XLI show that as a rule the farmer who tills a small acre- 
~ age does not get better yields than those who till larger areas, at least 
within the limits of the areas found in this study. 
Taste XLI.—Yield of crops per acre on 378 owner farms, Chester County. 
Number F 
Acres. offarms.| ©°- Silage. | Potatoes.| Wheat. Oats. Hay. 
PAIL OSS! Seren cist. coc cetere into aia =ju 54 62.2 10.8 72.1 25.1 37.0 1.4 
LO QUse6S cee esese ees eaeaeem 61 67.2 12.0 81.5 25.3 38. 0 EG) 
Gl. UO USES Bae Eeeese hese eEeeeaes 60 64. 6 15.3 78. 2 25.6 44.8 1.4 
O10 IC OSE ae eee 68 64.5 12.7 79. 6 24.1 43.0 1b 8} 
QUE (0) UA) ies a ee ee eee 52 66. 7 12. 6 76.1 24.8 42.9 1.3 
ZT COULOO Mass os SoS Se hoe 2 cieicie 61 66. 0 12.5 75.8 24.3 41.4 13 
Owor lO seo ees eee 22 64. 7 13.7 88. 1 25. 8 38. 0 13 
PNET ACO Me ye oe | 378 65.3 13.1 78.8 24. 8 41.6 133 
- There appears to be very little relation on these farms between 
size of farm and yield per acre. 
RELATION OF YIELD PER ACRE TO LABOR INCOME. 
While Table XLI shows very little relation between size of farm 
and yield per acre, Table XLII shows that within certain very wide 
limits there is a very distinct relation between yield per acre and 
labor income. The crop index, which is used as a measure of the 
yields on a given farm, is found as follows: Suppose a given farm 
produces— 
500 bushels of corn on 10 acres; 
200 bushels of wheat on 10 acres; 
25 tons of hay on 20 acres; 
AGtotakot a a: Sabo 40 acres. 
Suppose, further, that the average yields in the locality are such 
that, on the average, farmers produce— 
500 bushels of corn on 7.7 acres (65 bushels per acre) ; 
200 bushels of wheat on 8.0 acres (25 bushels per acre) ; 
25 tons of hay on 16.7 acres (1.5 tons per acre) ; 
——— 
A total of_________ 32.4 acres. 
| The crop index of the farm in question is now found by dividing 32.4 
__ by 40; that is, by dividing the average acreage in the community by 
_ the actual acreage on this farm required to produce the quantities 
of these products which this farm produces. In this case the crop 
index is 0.81. Roughly speaking, this means that the yields on this 
farm are 81 per cent of the average of the community. 
