14 
BULLETIN 511, U. S. DEPARTMENT OF AGRICULTURE. 
yields is $55. Aside from crop yields there are many economic and 
sociological features which enter into the determination of the 
market price of land; for example, land in the Mississippi Delta will 
produce as much or more corn per acre than the land in the northern 
Mississippi Valley corn belt, yet the environment and conditions in 
the Delta are such that the land sells for less than half what the corn- 
belt land will bring. It is probable that in the cotton belt the eco- 
nomic and social features of an area have more to do with regulating 
the price of land than do crop yields. 
THE RELATION OF CROP ROTATIONS TO CROP YIELDS. 
Generally crop rotations affect crop yields. The rotations having 
the largest percentage of those crops which add organic matter to 
the soil, such as hay or pasture, are usually conducive to the best yields. 
Regarding this factor, the data from all the records taken have been 
compiled in Table IX to show the relation between the crop yield 
and the normal average percentage of cultivated land in cotton. 
When the combined data from all the areas are compared (Table IX) 
there appears to be no effect on crop yields of growing a larger or a 
smaller percentage of the land to cotton. In the South Atlantic divi- 
sion, however, where large quantities of commercial fertilizers are 
applied each year, better crop yields are secured where 40 per cent 
or more of the land is in cotton. This is probably due to the large 
quantities of fertilizers used, a part of which remains hi the soil from 
year to year. 
Table IX. — Relation of percentage of cultivated land in cotton and normal acre yields 
of cotton. 
Percentage of cultivated land in cotton. 
Areas. 
29 or less. 
30 to 39. 
40 to 49. 
50 to 59. 
60 to 69. 
70 to 79. 80 to 89. 
90 and 
over. 
o5 
s 
Eh 
s 
"3 
a 
2 
2 
"3 
1 
Pn 
2 
a 
Pn 
"3 
a 
3 
Yield. 
Farms. 
2* 
3 
£ 
a 
2 
£ 
\Lbs. 
31-133 
6 
33 
13 
16 
Lbs. 
1,316 
864 
696 
618 
5 
45 
13 
21 
Lbs. 
1,280 
10 
Lbs. 
1.060 
14 
23 
5 
24 
Lbs. 
964 
878 
730 
600 
10 
Lbs. 
l.ifin 2 
Lbs. 
1,225 

975 
631 
o 
Lbs. 
n 
South Atlantic division. . 
Intermediate areas 
Southwestern division 
36 
38 
6 
801 
737 
800 
901 53 844 
611| 231 645 
609 301 533 
10 780 
6 691 2 
16' 590 11 
0| 

1 500 
Total 
83 
3,471 
868 
68,3,494 
1 874 
84 
3,401 1L6 3,0S2 
850---- 
66 3,172 
793 
42 3,221 15 2,821 
805 1 940 
ll 500 
1 am 
It is generally found that the inherent fertility of the soil and the 
climatic conditions largely determine the crop yields. Another im- 
portant factor in determining the crop yield in many parts of the 
cotton belt is the quantity of fertilizers used. Of the areas studied, 
in the nine having the highest } T ields of cotton 70 per cent of the farms 
surveyed use commercial fertilizer, and the average application per 
