42 
BULLETIN 1377, U. S. DEPAETMENT OF AGRICULTURE 
Florence, S. C. (1). Though these experiments have not been in$ 
progress very long, having been started in 1914, they are the best 
obtainable on cotton at this time. 
The rotation concerned is a 3-year, system, described as follows: 
First year, corn and cowpeas; second year, oats followed by cowpeas; 
third year, cotton. 
All the rotation plots are repeated three times, as series A, B, and 
C, so that cotton yields are obtained for each year. Only cotton is 
grown in continuous culture (series D). The plots in both the rota- 
tion and continuous-culture series are numbered in the same order 
and the corresponding individual plots in each series are fertilized 
alike. 
The soil on which these cotton experiments are located is a very 
fine sandy loam of the Orangeburg series. Under cultivation, the 
surface stratum of this soil is of a grayish color, becoming pale yellow 
at a depth of about 5 or 6 inches. At depths of from 10 to 15 inches, 
the soil consists of a red, friable fine sandy clay. In reaction the soil 
is somewhat acid. 
In the Pee Dee station experiments no manure is used, hence com- 
parable yields are confined to the results obtained from the use of 
chemical fertilizers. Three of the plots, 24, 27, and 30, are fertilized 
annually with a complete fertilizer equivalent to a 1, 000-pound appli- 
cation of a 4-8-4 2 commercial mixture. Inasmuch as these three 
plots are given favorable fertilizer treatments, as indicated by the 
average yields of cotton, these plots have been selected for comparable 
yields. In Table 42 are given the fertilizer treatments and the 
average yields obtained on these three plots both in continuous 
culture and in rotation, compared with the treatments and yields of 
some of the other plots. 
Table 42. — Fertilizer treatments and yields of cotton on some of the experimental 
plots at Florence, S. C. 
[6-year averages] 
Plot 
Fertilizer materials (pounds per acre) 
Yields per acre 
of seed cotton 
(pounds) 
Dried 
blood 
Cotton- Acid 
seed phos- 
meal phate 
Muriate 
of 
potash 
Kainit 
Contin- 
uous 
culture 
Rota- 
tion 
7 
2 
250 
1,342 
1,335 
1,140 
1,240 
1,522 
1,692 
1,725 
1,255 
1,877 
1,862 
1,710 
1,680 
1,417 
1,699 
1,521 
1,485 
1,776 
1,650 
1,672 
1,675 
1,925 
1,846 
1,870 
1,880 
1,955 . 
1,846 
1,916 
500 
5 
83.3 
6 
333. 3 
12 
250 
500 
1G 250 
15 250 
83.3 
333.3 
8 
500 
83.3 
83.3 
24 
250 
500 
27 83. 3 
30 83. 3 
34 250 
35 250 
36 125 
37 500 
380 450 
380 ; 450 
250 
333.3 
83.3 
83.3 
83.3 
83.3 
83.3 
1,000 
1,695 
500 
500 
1,597 
1,785 
2 In South Carolina and some of the othern Southern States this analysis is expressed as 8-4-4, the 8 per 
cent referring to P2O5. 
