19 
Miller and Hume’ report: 
It is the custom to use no fertilizers on the Keys where this kind of soil is found 
and the land becomes exhausted after yielding three or four crops of pinéapples. 
At the end of this time the soil is completely worn out, and little more than the bare 
rock remaining it is abandoned. 
The analysis of such a soil shows nearly 5 per cent of lime, 0.30 per 
cent of potash, 0.95 per cent of phosphorus pentoxid, 24.55 per cent 
of humus, and 2.65 per cent of nitrogen. Although this contains a 
high percentage of calcium it is probable, by comparing it with the 
following analyses, that none of this lime was present as carbonate. 
To investigate this matter further, samples of soil were secured 
from two of the Keys through the kindness of the planters. The 
samples received are hardly soils in the strict sense of the word; they 
are composed exclusively of leaf mold, undecomposed leaves, and 
coral particles. Samples Nos. 209 and 210 were received from Mr. 
T. J. Johnson, of Planter, Fla., and Nos. 214 and 219 from Mr. Edward 
Gottfried, of Key Largo, Fla. No. 219 is a virgin soil and No. 214 is 
from a pineapple field which is now abandoned. 
Analyses of pineapple soils from Florida Keys (plants healthy). 

Soil constituents and reaction. No. 209. No. 210. No. 214, No. 219. 
—_— | | SE 
Per cent. Per cent. Per cent. Per cent. 
3.10 6. 62 eae 2.54 

PMISONT MO OMIAL GOL 225 ooo ls. tte. oe see eh cet eee te 1 
LSC A 0) See ee oe A I ee ee te ech Seopa 23 29 .19 “8 
PIS (CAC P OL oon eee te tek oe. oc ees ee IM 21.13 20. 34 17.01 10. 96 
ieoaSin CMCC) 8S sh igen Pe A os. oe ae 9 aS 56 - 69 17 Trace. 
Ferric and aluminic oxids (Fe,O3Al2O3).......-.......- 1.97 5:29 2.44 3.11 
Phosphorms pentoxid (PsOg) 6s. sess ete ok aed -40 .30 25 599 
PU NMt Itc TeaUCOl a een meee nl Ue ok Soe ee eee OF 71.83 66.92 76.99 83. 20 
AMC Ete pen reheated alee 99. 22 100. 45 100. 00 100. 21 
ENP OMN ees etc eee eS eee eee ee eS eee 1.89 1.97 2. 41 2.61 
AUS TAR See 6, ee ee Os Ee aes Seen A eeAD 19. 84 20. 05 13. 60 19. 59 
ROAMDOTATO RIC COO a 2s Se CELE . 2 Ae eae 11 05 9.18 7.59 1.90 
Calcium earbonate (CaCO3) ...:...-.- 22 5522-2 bane ee eek 25.14 20. 88 17.27 4, 32 
DAG INGREUO NU MEUSO ace eee mec cee one osee eee Alkaline. | Alkaline. | Alkaline. Alkaline. 


It will be seen that these ‘‘soils”’ are remarkable for their great 
content of organic matter (as is shown by the high percentages of 
volatile matter and nitrogen) and for their richness in plant food, 
which must be present in a form that is quickly available to the plants. 
The content of lime is high, and while a large part is combined with 
the humus there is still a high percentage of calcium carbonate. It 
is then evident that pineapples will stand a large amount of calcium 
carbonate in the medium in which they grow providing a very large 
amount of organic matter and humus is also present. 
The soil surveys of Porto Rico and the information obtainable from 
Cuba, Hawaii, Queensland, and the Florida mainland, concur in 
showing many cases of the failure of pineapples on calcareous soils 

1 Loc. cit. 
(Bull. 11] 
