26 
BULLETIN 31, PORTO RICO EXPERIMENT STATION 
whereas the trees in the limed soil with one exception fell below it. 
At the close of the test the trees in the four groups receiving lime at 
the rate of 2 tons or more per acre measured in height considerabty 
less than the check, and the trees receiving lime at the rate of 1 ton 
or less per acre measured just below the check. Each group receiv- 
ing nitrogen measured above the check, the difference being most 
pronounced for that receiving the most nitrogen. The extreme dif- 
ferences in height were less than 7 per cent below and 12 per cent 
above the check. In March, 1917, counts of the leaves per tree were 
made, and in September, 1917, the leaves, woody growth, and roots 
were weighed. Table 12 gives the results of the test. 
Table 12. — Effect of nitrogen and of lime on young coffee trees grown in cans 
Fertilizer applied 
Group 
Number of leaves 
(Mar. 12, 1917) 
Aver- 
age 
Weight of trees 
(Sept. 11, 1917) 
Weight 
in per- 
cent- ! 
age of 
check 
» 
Aver 
age 
weight 
Kind 
Amount 
Tree 
No.l 
Tree 
No. 2 
Tree 
No. 3 
Total 
Tree 
No.l 
Tree 
No. 2 
Tree 
No. 3 
Total 
in per- 
cent- 
age of 
check 
Ammoni- 
um sul- 
phate 
Sodium ni- 
trate 
Hydrated 
lime. . .. 
Nothing 
(check) . . . 
Grams 
24 
f 12 
24 
30 
36 
48 
f 5.9 
11.7 
23.4 
46.9 
93.7 
. 187. 4 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
167 
202 
177 
174 
191 
197 
126 
118 
143 
121 
157 
149 
155 
152 
179 
167 
177 
162 
271 
117 
153 
160 
132 
146 
142 
133 
223 
202 
192 
200 
198 
293 
130 
131 
109 
126 
138 
109 
144 
542 
583 
536 
551 
551 
761 
373 
402 
412 
379 
441 
400 
432 
181 
• 199 
134 
144 
Gms. 
470 
465 
385 
391 
510 
560 
362 
325 
319 
304 
424 
391 
408 
Gms. 
429 
430 
457 
409 
452 
600 
373 
435 
373 
410 
375 
415 
351 
Gms. 
442 
369 
394 
398 
439 
490 
389 
364 
1307 
349 
364 
294 
339 
Gms. 
1,341 
1,264 
1,236 
1,198 
1,401 
1,650 
1,124 
1,124 
999 
1,063 
1,163 
1,100 
1,098 
122.1 
115.1 
112.6 
109.1 
127.6 
150.3 1 
102.4 
102.4 
91.0 ; 
96.8 ! 
105. 9 i 
100.2 
100.0 
122.1 
■ 122. 9 
99.8 
100.0 
1 The weight of tree 3 of Group 9 fails to show full development. Four branches were broken off prior to 
weighing, and the weight of leaves and woody growth (roots excluded) was 17 per cent less than that of the 
other two trees of the same group. 
The marked effect of nitrogen on foliage and development of the 
young trees is very evident as compared with results from liming. 
All except two trees fruited in 1917. Group 6 gave the highest 
yield, followed by Group 1. The lime-treated and check trees 
yielded the same average number of cherries, whereas the average 
yield from nitrogen-treated trees was 87 per cent greater. 
To permit of further comparing the effect of ammonium sulphate 
and sodium nitrate on coffee, another test was made, using a heavy 
red clay soil which was removed to a spade's depth, ground, 
screened, and thoroughly mixed. In March, 1922, 70 containers 
were each planted with 2 seedlings from a single tree of Columnaris 
coffee, the seed having been planted in flats the previous December. 
The test was divided into 7 groups of 10 containers each, of which 
1 was left to serve as a check, 4 received sodium nitrate (8, 10, 12, 
and 16 grams, respectively), and 2 received ammonium sulphate 
(8 and 12 grams, respectively, per container per application). Fer- 
tilizers were applied May 3 and November 3, 1922, and May 3, 1923. 
At two and one-half months following the first fertilizer appli- 
cation a pronounced difference was noted in growth and vigor. of 
