February i, 1888.] THE TROPICAL AGRICULTURIST. 
5 r >9 
To Ike Editor of the " Ceylon Obsevverr 
PADDY CULTIVATION IN CEYLON: 
ANALYSES OF SOILS. 
20lh January 1888. 
Sin,— A good deal lias appeared of late in the 
Observer on the subject of paddy cultivation, but 
no analyses, so far as I am aware, of fertile paddy 
soils of Ceylon have been published; so, in tho 
absence of exact information aB to the composi- 
tion of such soils, the next best thing to know is 
the composition of soils on which paddy culti- 
vation has failed. WiLh the consent of the Assistant 
Government Agent, Nuwara Eliya, I give below anana- 
lysis and report I made for him on in Dec of 188G :— 
" Analysis of a sample of soil from the YVala- 
ganwala paddy fields, on which paddy grown, but 
does not mature its seed, received from tho Principal 
Civil Medical Ollioer, Colombo. 
Moisture ... ... 2-600 
• Organic matter ... ■•• 
Soluble in standard hydrochloric acid : 
Silica ... ••■ j/jjW 
Iron peroxide ... ••■ :5"52G 
Irou protoiidc ... ••• ' "JW 
Alumina ... ••• S J 640 
Lime ... ... 'J 2 * 
Magnesia ... ••• ""5 
Potash ... .. 077 
Soda ... - -028 
Phosphoric acid ... ... "034 
Sulphuric acid .. ... '060 
Chlorine ... - '012 
'••Insoluble Silicates ... ... SO 000 
100 000 
* Containing Nitrogen... .. '129 
Equal to Ammonia ... ... "157 
«* Containing Silica ... ... 72000 
" The soil was dried in air and passed through 
a sieve of 10 meshes to the lineal inch, which kept 
back 3-1 per oent of gravel, nearly pure quartz, 
and -654 per cent of organic matter as roots, seeds, 
Ac. The soil which passed through the sieve of 
10 meshes was powdered till it all passed through 
a sievo of 40 meshes to the lineal inch, and it was 
this prepared sample which was subjected to 
chemical analysis, with the foregoing results. 
" The soil was of a free, sandy nature, containing 
a very large proportion of insoluble silicates. The 
element of plant food in which the soil appears 
to mo to be specially deficient is phosphoric acid. 
I made two determinations of tho phosphoric acid 
in the hydrochloric acid solution, with closely con- 
cordant results, obtaining only 034 per cent. In 
a nitric acid solution of the soil, I obtained -04y 
per cent. The deficiency of phosphoric acid would 
account for the paddy not yielding seed, as that 
is by far the most abundant of the mineral con- 
stituents of rice grain, as tho following analyses 
from standard works of the ash of rico grain show:— 
Phosphoric acid 0223 . r )330 
Potash ... 2021 IS-48 
Soda ... 2-49 10-07 
Limo .. 7-18 1-27 
Maguesia ... 420 1109 
Oxido of iron 2- 12 45 
Chloriuo ... Not deturniined '27 
Silica ... 1-37 3-3.'. 
99-81) '.'0-54 
On tho other hand the whole amount of mineral 
matter in rice grain is so very small, -9 per oent in 
dried rice. -3 in naked rice, compared with other 
cereals, e.g., wheat 17, oats 2-7, peas 2- 1, beans •'(• 1, 
that I think it would bo advisablo in tho abionoo of 
uny aimlytioB ol soil from fertile paddy-fields (I have 
seen no such analyses) to have a few soils from 
fields known to produco good crops oi padfly at 
lysed for comparison. The soil contained -830 
per cent of protoxide of iron, which is generally 
regarded as injurious to vegetation. I do not think 
that any of the Ceylon soils are quite free from 
this ingredient, so that whether or not this con- 
stituent be present in deleterious proportion would 
also have to be determined by comparison with 
the composition of fertile soils. Protoxide of ir.-;i i I 
converted into the harmless or beneficial peroxide by 
aorating the soil by mechanical working or by liming. 
" I understand * that sometimes, when paddy-li dd I 
become sterile, the Sinhalese simply remove a 1 lyer 
of the surfaoe soil altogether, and, by planting 
upon the underlying soil, get goof crops. An < <- 
animation of the sub-soil might indicate whether 
or not such a course would be advisable ? As the 
result, however, of the foregoing analysis, I would 
recommend the application of bone-dust t~> tho 
soil with the view more especially of increasing 
the amount of phosphoric acid present. I have 
potted the balance of the soil in four pots and 
shall try the effect of different manures. In the 
event of my getting definite results, 1 shall give 
due notice of the same." M. Cochhan, v. c. s., 
Analyst. 
It is a pity that as yet the investigation into 
the cause of the sterility of the paddy grown on 
the Walaganwala lields has not been supplemented 
by manurir.g experiments on the spot, as, when 
attempting these on the small scale in flower-pots, 
the experiments are necessarily carried on under 
abnormal conditions. In the present case, I divided 
the soil not required for the analysis into four 
equal parts, which allowed somewhat less than 
2 lb. of soil to each pot. One of these was left 
unmanured, one was mauurod with suflicient boni-- 
dust to add -111 per cent of phosphoric acid to 
the soil, another with suflicient slaked lime to add 
•21)0 per cent of lime to the soil. The fourth was 
manured with a little dry cowdung. Four seeds 
were planted in each pot on the 18th of January 
1887. The four pots were placed in tho back 
verandah, watered regularly and left to take their 
chance. They only received a litt'e of the sun's 
oblique rays in tho afternoon. I could not venture 
to put them out into Ihe open, lest the blades 
should be cropped by birds or quadrupeds. No 
doubt, had tho plants got more sun, better results 
would have been obtained. 
The average time taken for the first three <cp:\ - 
to germinate and appear above ground was, in the 
soil manured with lime, 9 days ; in the unmanuied 
soil, 12 days; in the soil manured with bone- 
dust, 15 days. In the soil manured with cowdung, 
the first two seeds took 14 and 27 days respectively. 
On the 2(ith of May, I measured the growth 
from the ground to the lips of the blades. Tha 
results, togothcr with some other data, are tabu- 
lated below: — 
Greatest length 
Mean length 
Date when in ear 
Number of ears 
Seed* in each ear 
Length of .straw 
from ground to 
lowest seed ... 
ft. in. 
:i <•>. 
3 9" 
14 
in. 
B 
a 
ft. 
2 '>.'. 
a 7} 
Mav S 
o 
12 
■a 
J3 
'S 
4) □ 
b 
h: = 
C 
a? 
£ 5 
S c 
1 s 
.-. - 
« 
ft. in. 
It. 
iu 
2 71 
2 
0 
2 21 
1 
M»5 2« 
1 
lit. 7,p. Hi. t>4in. 
• 1 uUniiialiuii received freiu the Kov. S. Culcv 
