13 
Summary of the results of applying fertilizer* to seven crops of rice. 
Plat. 
Fertilizer per crop. 
None 
Superphosphate, 225 
pounds; potassium 
sulphate, 120 
pounds 
Ammonium sulphate, 
150 pounds; potas- 
sium sulphate, 120 
pounds 
Ammonium sulphate, 
150 pounds; super- 
phosphate, 225 
pounds 
None 
Ammonium sulphate, 
150 pounds; super- 
phosphate, 225 
pounds; potassium 
sulphate, 120 
pounds 
Ammonium sulphate, 
300 pounds; super- 
phosphate, 450 
pounds; potassium 
sulphate, 240 
pounds 
Ammonium sulphate, 
300 pounds 
Ammonium sulphate, 
150 pounds 
None 
Series A— one application 
annually. 
Paddy. 
Total. 
Pounds. 
110,560 
13,519 
14,419 
16,134 
13,857 
16, 668 
20,084 
21,352 
19,476 
13,130 
In- 
Pounds 
26 
2,641 
3,175 
6,591 
7,859 
5,983 
Total 
cost of 
fertili- 
zer. 
§22.20 
37.20 
33.00 
46.20 
92.40 
48.00 
24.00 
Total 
profit 
or loss. 
— $21.55 
14.05 
33.02 
33.17 
72.37 
148.47 
125.57 
Series B— two applications annually. 
Paddy. 
Total. 
Pounds. 
Ul,567 
14,559 
19,978 
In- 
crease. 
Pounds 
4,908 
22,050 6,) 
15,971 
23,268 
29,453 
29,282 
24,091 
14, 170 
8,198 
14,383 
14,212 
9,021 
Total 
cost of 
fertili- 
zer. 
S38.80 
65.10 
57.75 
80.85 
161.70 
84.00 
42.00 
Total 
profit 
or loss. 
138. so 
57.60 
116.75 
124. 10 
197. 87 
271.30 
183.52 
Aver- 
age 
profit 
(+)or 
loss (— ) 
per 
acre. 
-15.14 
+ 9.39 
+ 16. 
4-17.73 
+28.27 
+38.76 
+26.22 
3 Injured by cold water flowing directly onto plat. Not included in averages. 
The results of these experiments justify the conclusion that for 
the present at least this soil is in need of nitrogen only. Little or no 
effects were produced in any case from the use of superphosphate 
or potassium sulphate, either when applied with or without am- 
monium sulphate. It is the custom of the rice growers to apply fer- 
tilizer, when used at all, to the spring crop only, believing that the 
more unfavorable weather conditions at that time necessitate the use 
of stimulants, whereas under the more favorable conditions that pre- 
vail during the late summer and early fall fertilizers are less needed. 
Moreover, it has been considered that the residual effect resulting from 
the spring application makes itself felt in the fall crop. The above 
experiments prove conclusively that neither of these opinions is 
justified. The growth of the fall crop, when more favorable weather 
prevailed — i. e., higher temperature and longer days — was affected to 
approximately as great extent by ammonium sulphate as was that 
of the spring crop. On the whole there appeared no evidence of a 
cumulative effect even from the heaviest application when made twice 
annually. 
