juLY I, 1893.] THE TROPtCAL AGRICULTURIST. 
3; 
Important constitventsofplaiit food in the primings 
oj IQ and 3,110 tea trees respectively . 
10 Tea trees. 
° CD 
0) 41 
C 
cS 0 
Ui ^ 
P^. Co" 
"U * ic 
b 'S! 
ranches 
;th spnie 
I'wigs. 
— <u 
e22 
Ounces 
Ounces. 
Ouncee. 
T'nn n Ma 
XT U UIIUd. 
Nitroijen 
Potash ■ • ■ 
Phosphoric acid .. 
Lime 
1-583 
•755 
•202 
•533 
•583 
•243 
•089 
•192 
2-166 
-998 
-291 
•725 
42-10 
19-40 
5-66 
14-09 
3-073 
M07 
4-180 
81-25 
Calculation of the amount of fertilising material 
removed per annimi from one aire of 
land by the tea crop. 
A sample of Ceylon unassorted tea (August 
189'i) consisting of one-tliird high-grown from 
the Great Western Estate, 4,400 to 5,200 feet 
eleva,tion, one-third grown at medium elevation 
2,400 feet; from Koseneath Estate, and one-tliird 
grown on a lowcountry Estate, Degalessa, was 
analysed by Mr.. R. R. Tatlock F.E.s.E., F.I.C, 
F.C.S., City Analyst for Glasgow with the folloAv- 
ing result: — 
Agrictdtural Analysis of a sample of Ceylon 
unassorted Tea from High, Medixim 
and Lovj Elevations. (Tatlock.) 
Moisture ... 
Nitrogen ... 
Potash 
Lime 
Phosphoric Acid 
Total Ash 
Ash Analysis 
Per cent, per cent. 
4-82 — 
4-38 
2- 27 
•57 
•76 
5 40 
42-04 
10'56 
14 '08 
If we take the crop of made tea at 400 11). 
per acre per annum, we can with the above 
data readily calculate the amounts of the import- 
ant constituents of plant food removed from the 
soil per acre per annum by the tea crop, thus : — 
Nitrogen ... 4-38 per cent of 400 lb. := 19-52 lb. 
Potash 2-27 „ 400 lb. =10-08 lb. 
Phosplioric Acid -76 „ 400 lb. = 3^04 lb. 
Lime -57 „ 400 lb. = 2-28 lb. 
34^92 lb. 
The total amount of the important constituents 
of plant food removed annually from the soil by 
tlie tea plant, supposing the prunings are ail 
returned, amounts to rather less than 35 pounds. 
If the prunings are lost, the totfl,! amount of 
important constituents of plant food withdrawn 
from the soil per acre annually is calculated by 
adding to the loss by crop two-thirds of the 
fertilizing material in the prunings, as pruning 
only takes place about once in eighteen months. 
The loss thus calculated amounts to 47-59 lb. 
of nitrogen, 6-82 lb. of phosphoric acid and 23'021b. 
potash— total 77 '43 lb. When the prunings are 
burned and the ashes only returned to tlie soil, 
the loss to the soil is all the nitrogen in both 
crop and prunings, i.e., 47 "59 lb; but tlie phos- 
phoric acid and potash in the crop only are lost, 
viz., 3-04 and 10-08 lb. respectively— total 47-59 lb. 
Man uring of Tea. 
The planter naturally looks to tlie Agricultural 
(^beittiijt for useful su^'^'estions on the subject of 
manuring, and it is certainly greatly to be 
desired that a simple rule could be laid down 
for compounding a manure for any particular 
crop that would yield economically the best 
results. There are, however, a good deal of data 
wanting before it is possible to calculate with 
anything approaching scientific accuracy the 
composition of a manure that will, even on a 
given estate, be agriculturally sufficient, without 
some ingredient being in excess. We require to 
know the proportion of plant food supplied in 
tlie annual rainfall and the proportion lost by 
drainage as well as the composition of the soii. 
The amount of plant food lost in the soil 
removed by surface wash would also require to 
be known and allowed for. Supposing the 
weiglit of soil lost per acre were approximately 
determined, an ordinary analysis of such soil 
would give an idea of the loss of available 
plant food by this cause, e.g., if the analysis 
were to shew -2 per cent of nitrogen, -1 of 
phosphoric acid and -1 of potash, then the loss 
of important ingredients of plant food would be 
4i lbs. of nitrogen, 2^ lbs. of phosphoric acid and 
2i lbs. of potash, in all 9 lbs. of available plant 
food per ton of soil lost. 
The amount of plant food removed from the 
soil by the tea crop, and also by tea prunings, 
when tliese are not returned to the soil, has 
been determined with all the requisite accuracy,, 
and the results have been recorded in thet 
foregoing pages. The analyses of manures will 
be given in very full detail in the ChajApii 
dealing with Manures as a special subject. Th^' 
necessary data for arriving at the approximate 
commercial value of manures will also be there 
given ; meanwhile, I give in three tables what' 
cannot fail to be useful data for manuring 
experiments with tea. With reference to these 
I shall fii-st offer a few words of explanation. 
The amount of manure required to return to 
the soil exactly what has been removed by crop 
only, or by crop and prunings may be termed 
a theoretical dose, and in this connection we 
confine our calculations to the three most im- 
portant ingredients of plant food— nitrogen, 
pliosplioric acid and potash. From the agricul. 
tural anal y. sis of Ceylon tea and of tea prunings 
already given, we therefore calculate tlie theo- 
retical dose of nitrogen, phosphoric acid, and 
potash (in the case of crop only) as the weight 
of tliese three constituents contained in two 
years' plucking, or 800 lbs. of made tea ; and, 
in the case of both crop and prunings, as the 
^veight in 800 lbs. made tea plus that in IJd 
times tlie amount of a single pruning, as this 
operation is conducted at intervals of about 
eighteen months, thus : — 
Theoretical doses of Manure. 
For tea crop For tea crop 
only. i^c prunings. 
lb. per acre, lb. per acre- 
Nitrogen 39-04, ... 95-17 
Potash 20-16 ... 46-03 
Phosphoric Acid . 6-08 ... 13^63 
The nitrogen table, therefore, gives tJie 
weiglits of manures in jiounds per acre which 
contain 39-04 lbs. and 95'17 lbs. respectively of 
nitrogen. 
The potAsh table gives the weights of mannreft 
in pounds ])er acre which contain 20^16 lbs. and 
46^03 lbs respectively of jwtash. 
Tlie phosphoric acid table gives the weigJits 
of manures in pounds per acre wliich contain 
6-08 lbs, and 13-63 lbs, respectively of jdiosnhofio 
Plant food. 
