May I, 1891 .] 
TROPICAL AGRiCULTCPilST. 757 
NITRATE OE SOEA. 
The transition from nitrogen-absorbing plants 
about which I wrote recently, is natural to nitrogen 
in its concentrated form as derived from the 
nitrates or saltpetre of Chile, the supplies of which 
may be rendered uncertain by the 
WRETCHED CIVIL WAR 
which has arrested the previously satisfactory pro- 
gress of this leading Boulh American Republic, 
although Peru and Bolivia also export nitrate of 
soda. There is an interesting article on the chief 
article of. Chilian commerce,— the mainstay of its 
revenue, in truth, — in the latest number of the 
“ Agricultural Gazette of New South Wales.” Mr. 
Anderson, the Director of Agriculture of the above 
colony, believes that this valuable fertilizer has 
been formed by the decomposition of sea-weed and 
other organic matter : — 
The nitrogen of which has become nitric acid by 
the process of nitrification, which acid has eventually 
formed nitrate of soda or Chili saltpetie. In its crude 
state it contains from 27 to G5 per cent, of the nitrate 
mixed with common salt, sulphate of sodn, gypsum, 
and other impurities. After purification tho commer- 
cial article is supposed to contain 95 per cent, pure 
nitrate of soda, or — in the language of analysis— it has 
a refraction not exceeding 5 p“r cent. 
The exports from Chile rose from 729 tons in 
1878 to 1,000,000 of tons in 1889, mainly from 
the discovery that the nitrate added so largely to 
the saccharine matter in beetroots. The results 
were the 
ENORJIOUS IXCREABE OF EXPORTS 
I have mentioned and tho sinking of the prices 
of nilrate from £16 to £9 per ton and of beet sugar 
from 15s to 11s per cwt. To quote again 
Tho mauurial value of iiitrnto of soda is due to the 
15'75 per cent, of nitrogen which this salt coataioB. 
It is extremel.y eolublo, and thcretoro be used only 
ou growing crops which cau utilise it, and not allow 
it to be washed out of the soil into the dmiiis. 
Reckoeing sulphate of aranioiiia, which coulains 20 
per cent, of nitrogen, at its Sydney price of £13 a 
ton. nitrate of soda is worlb £10 5s a loii. and is there- 
fore well worth experimenting with at anything under 
that price. 
There is considerable rivalry between this salt and 
sulphate of ammonia as the two chief sources of 
nitrogen amongst artificial manures, but it is now 
generally admitted that ou dry soils and on light 
loamy soils the former is to ho preferred, on heavy 
clay land and wet soils, the latter. The nitrate ha.s 
been proved to be of great value to all straw 
growing plants, espieoially wheat and barley, 
peas, vetches, lupinee, clover, buck wheat, rape, 
sugar-beet, potatoes, celery, onions and linseed ; 
with maize and tobacco the ammonia salt does 
better. Dr. Voeloker has shown at Woburn that Ij 
cwt. of nil rate of soda gave £1 8 s 6 d worth of wheat 
and 12s 6 d worth of straw. With barley and potatoes 
also the results are very satisfactory. 
Many farmers argue that nitrate of soda exhausts 
the soil, and therefore loaves it in a poor state for the 
Bucceediiig crop. It will bo at once seen that the larger 
it makes the crop the greater is tho quality of mineral 
matter it must take out of the soil ; but which is more 
valuable— the increased yield of grain and straw, or 
the few pounds of potash and phosphoric acid ? 
For (xample, 1 cwt. of nitrate of «cda may increase 
a crop of oats by 3 cwt. of grain and .5 cwt. of straw, 
whicli will remove from the soil about 4 lb. of phos- 
phoric acid ami 111 b. of potash; but the increase in 
tho crop is worth about 25s., wliilo tho mineral matter 
can be replaced by 20 lb. of superphosphate and L cwt, 
of kaiuit for 4.s Cd. 
This points to tho expediency of using nitrate of 
soda with some form of phosphoric acid, such as bono- 
dust or superphosphate of lime ^which must be dry 
whoa mixed with the uilpate, or d' compcsitiou may 
Do 
ensue), and some source potash of such as the sulphate 
or kaiiiit. 
It is very valuable in enabling crops to resist tlie 
attacks of small parasites such as the beet-fly, turnip- 
fly, and fungi, owing, probably, to the rapid develop- 
ment of chlorophyll in the leaves by which the plants 
are placed beyond tho dcstiuotivo influenco of those 
parasitic pests. 
VVe cannot help thinking of the probable 
GOOD EFFECT ON RICE 
of an application of nitrate as we read ; — 
On a good mineral soil, IJ cwt. of nitrate of 
soda has been found to increase the yield of wheat 
from 27 bushels eud 1 ton of straw, to 44 bushels 
of grain and l.J tons of straw, 
For vegetable gardens and fruit orchards applica- 
tions of this substance seem specially valuable : — 
For the market gardener who wishes to raise immense 
crops of early vegetables, this manure has proved a 
great boon. Instead of applying 75 to 100 tons of 
stable manure per acre, aud working the c-ame in with 
great toil, ho now applies 250 lb. of nitrate of soda 
aud 600 lb. of superphosphate in early spring before 
drilling in the seed, and again 2501b of nitrate when 
the plants are a few inches high, and yet another 
similar dressing in three or four weeks. The results 
in promoting great growth aud early maturity are sur- 
prising. Why ? First, because this amount of nitrate 
of soda really contains more nitrogen than 25 tons of 
average stable manure would supply, and it contains 
the nitrogen in a form — nitric acid — at once available, 
whereas the nitrogen of the dung has to be changed 
into nitric acid for the use of the plant by the presence 
of lime or carbonate of lime or potash in the soil, 
and the slow process of nitrification — a process that 
depends ou minute living organisms (bacteria) produ- 
cing a ferment in tbo soil, and must have a proper pro- 
portion of moisture with a temperature tanging Irom 
54° F. to 98“ F, It can hence be readily understood 
how nitrate of soda acts so wonderfully in a drying 
cold spring, where dung or sulphate of ammonia may 
refuse to act. Hence also may be deduced the wis- 
dom of applying dung in the autumn and tho nitrate 
as a valuable supplement in the early spring. For 
oai'ly cabb.vges, cauliflowers, onions and celery, its 
value has been proved. With regard to fruit, it is of 
great service in promoting the formation of sugar and 
early maturity. A dose of |lb will often recover a 
sickly lemon or maudanu tree. 
The article from which I have been quoting ia 
followed by one on the cultivation of Ooff'ea arabica 
in certain parts of New South Wales, where it grows 
well and ia singularly free from disease. No doubt 
tea and coffee, like sugar, could be grown in many 
parts of Australia, but the 
HIGH WAGES OP LABOUR 
place an insuperable bar to profitable cultivation of 
such plants in competition with places whera 
comparatively low priced labour ia plentiful. 
— ♦ 
” Timehri.” — Tho December 1890 number of this 
journal of tho Royal Agricultural and Commercial 
Society of British Guiana, has the following contents: — 
Paper.-. — The Post Office in British Guiana before 1860, 
by James Rodw.iy, f.l.s.; Fireflies, by Lady Blake, 
Jamaica ; Statute Law Revision, by Dr. J. W. C'ar- 
ringmn, C.M.G., q c.; The Necessity of Pure Air tor 
Health, by B. D. Rowland, M.n., c m., Ediu. ; Notes 
ou the Geological iteports of British Guiana, bj' tho 
Editor ; On Parasites, by A. T. Ozzard, vi.it.c.s.. Eug- 
Und ; Oontriicts wilh Oaiie Gutters, by A. li. Gilzoau ; 
Notes on Scale and other Parasitical Iniects, by R. 
Ward ; Ou the Tipper Berbico River, by tho Editor ; 
The Barbados Sugar Cane Experiments, by J. B. Har- 
rison, W.A., T.G..S. , F.c s., ice. Occasional Notes. — Gold 
and Diamonds in British Guiana ; Rice growing in 
British Guiana ; D.iid ripe nanauas ; Scale lusects ; 
Young Aboma, Ropt rta of Society’s Muutiug.s, from, 
July to December, 1890. Li -t of Popular Seiviieg Leo- 
turoB. 
