45 
Table XIX. — Citrate solubility compared with vegetation tests as a measure of the acalla- 
biJity of the phosphoric acid in guanos. 
Source of phosphoric acid 
(P«O s ). 
Citrate- 
soluble 
portion 
of total 
phosphoric 
acid in 
guanos. 
Efficiency 
of phos-" 
phoric acid 
compared 
-Kith that 
of acid 
phosphate 
= 100 by 
vegetation 
tests. 
Source of phosphoric acid 
(P»0 5 ). 
Citrate- 
soluble 
portion 
of total 
phosphoric 
acid in 
guanos. 
Efficiency 
of phos- 
phoric acid 
compared 
with that 
of acid 
phosphate 
= 100 by 
vegetation 
tests. 
Per cent. 
38 
48 
22 
23 
21 
56 
5 
40 
38 
43 
93 
93 
18 
8 
5 
9 
16 
9 
5 
16 
81 
68 
29 
3S 
27 
28 
22 
42 
24 
26 
40 
14 
94 
101 
16 
26 
25 
16 
32 
26 
17 
9 
70 
65 
Guano No. 816 
Per cent. 
23 
23 
80 
3 
27 
21 
11 
28 
89 
13 
15 
80 
34 
10 
10 
2S 
20 
31 
33 
24 
31 
26 
12 
46 
15 
5 
47 
63 
88 
38 
18 
26 
66 
Guano No. 818 
Guano No 321 
Guano No. 819 
Guano No. 824 
Guano No 841 
2 
14 
Guano No 842 
18 
10 
16 
Guano No. 458 
Guano No. 852 
60 
Guano No. 460 
27+ 
23 
Guano No. 860 
Guano No 881 
65 
Guano No. 497 
Guano No. 889 
12 
Guano No. 498 
Guano No. 499 
Guano No. 912 
Guano No. 916 
Guano No. 917 
Guano No. 923 
Guano No. 92S 
Guano No. 931 
Guano No. 932 
Guano No. 936 
Guano No. 939 
Guano No. 943 
Guano No . 945 
Guano No. 947 
Guano No. 955 
Guano No. 957 
Guano No. 959 
Guano No. 961 
Guano No. 965 
Guano No. 966A 
Guano No. 966B 
1 
1 
Guano No 499 \ 
3 
Guano No. 500 
5 
Guano No. 500A 
14 
Guano No. 501 
31 
Guano No. 502 
19 
Guano No. 503 
36 
Guano No. 503A 
20 
Guano No. 504 
10 
Guano No. 505 
4 
3 
8 
29 
2 
3 
64 
39 
9 
104 
77 
35 
39 
4 
35 
1 
19 
24 
4 
31 
12 
6 
10 
15 
9 
51 
Guano No. 505A 
6 
30 
27 
13 
56" 
44 
11 
84 
80 
46 
52 
13 
28 
10 
Guano No. 506 
2 
Guano No. 507 
34 
Guano No. 508 
33 
Guano No. 509 
Guano No. 733 
49 
18 
Guano No. 734 
20 
Guano No. 7.50 
8 
Guano No 751 
Guano No. 970 
46 
68 
11 
92 
82 
13 
12 
73 
72 
32 
10 
9 
2 
78 
25 
Guano No. 780 
Guano No. 971 
Guano No. 975 
Guano No. 977 
Guano No. 978 
32 
Guano No. 7S4 
Guano No. 785 
Guano No. 790 
4 
94 
87 
Guano No 793 . 
Guano No. 980 
Guano No. 981 
Guano No. 982 
Guano No. 985 
Guano No. 1011 
Guano No. 1013 
Guano No. 101^ 
5 
Guano No. 796 
3 
Guano No. 797 
39 
50 
18 
27 
34 
15 
16 
30 
30 
33 
Guano No. 797A 
31 
Guano No. 798 
Guano No. 799 
11 
2 
Guano No. S06 
2 
Guano No. 807 
Floats 
4 
Guano No. 810 
Slag a 
68 
Guano No. 811 
Bone meal 
31 
Guano No. SUA 
a Solubility in 2 per cent citric acid. 
By the citrate test the 92 samples had an average of 33 per cent of 
the total phosphoric acid available, and by the vegetation test, 26 per 
cent. 1 Sixty-four of the 92 samples showed excellent to fair agreement 
between the chemical and vegetation tests of availability. Of the 28 
samples showing poor agreement, 6 gave higher results by the vegeta- 
tion than by the chemical test, and 22 lower results by the vegetation 
test. Fresh, or only slightly decomposed, bat manures showed a 
very fair agreement between the two methods for availabilities. 
Where one sample was tested several times, the mean value was used in calculating the general average. 
