1 Mar., 1902.] QUEENSLAND AGRICULTURAL JOURNAL. 153 
Agriculture. 
FIRST STEPS IN AGRICULTURE. 
14ruH Lesson. 
SECOND STAGE. 
By A.J.B. 
We will, in this lesson, take the artificial manures as I classified them in 
Lesson 13, that is to say as Nrrrogenous, PuospHartc, and PorasH manures. 
A NirroGgENots manure is one which contains more or less nitrogen. 
FARMYARD MANURE is one of these. Amongst the artificial manures I men- 
tioned Peruvian Guano as being nitrogenous, and I told you how rich it was 
in ammonia many years ago, but all the best deposits have been worked out 
since I was at the Guano Islands, and the guano is now more of a phosphatic 
‘character, being very poor in nitrogen, the latter constituting only about 4 per 
cent. and the phosphates about 50 per cent. of the manure. There is also a 
small percentage of potash in it. 
The offal from fish-curing establishments is called Fis Guano, and this 
also supplies about 10 per cent. each of ammonia and phosphate of lime. 
Nrrrate or Sopa is a most valuable artificial fertiliser. It contains 
nitrogen, the most important of plant foods, in its most readily available form. 
The effect it has upon a soil poor in nitrogen is little short of marvellous, 
especially in the case of wheat and grass. It acts almost immediately it is 
applied, and is particularly useful in a dry season. It is a compound of nitric 
acid and soda, and is found in large deposits in some of the rainless regions of 
the west coast of South America, mixed with earthy matter which is removed 
from it, leaving a substance containing 95 per cent. of the fertiliser, the 
remainder being chloride of sodium or common salt. 
- Unfortunately, it is the most expensive of manures, and scientific men are 
hoping to devise a means whereby the nitrogen of the air may be united to the 
sodium of common salt, and so produce nitrate of soda artificially and cheaply. 
It is a suitable manure for all crops except legumes, especially for cereals, 
used at the rate of from 1 to 2 cwt. per acre. You will see how very valuable 
a fertiliser it is when I tell you that on two trial plots, one with nitrogen, the . 
other without, that with nitrogen yielded 64 bushels of barley and the other 
only 36 bushels. 
For mangolds it is also good. A mixture of 134 to 2 ewt. of mtrate 
and 2 to 4 ewt. of common salt, applied in two dressings, is a fair proportion. 
The first dressing should be applied when the young plants are old enough 
to use some of the nitrogen, and the other some time afterwards as a liberal 
top-dressing. 
Never mix Settee with nitrate of soda, because the free sulphuric 
acid in the superphosphate sets free the nitric acid in the soda. 
Now, you want to know why plants treated with nitrate of soda suffer 
less from drought than others not so treated. The reason is, that it rapidly 
permeates the soil, so the roots have not to go down in search of it, nor even 
to seek it immediately below the surface, which would result in the evil of 
shallow rooting. The growth of the young plants is so stimulated that the 
roots are able to strike far down into the soil without any delay, so that dry 
weather coming on afterwards will not affect them injuriously. 
ScuLpHare or Awaonra is a compound of ammonia and sulphuric acid, 
derived from the refuse of gasworks. It is quite soluble in water, contains 
more nitrogen than the nitrate just spoken of, but is not so quick in its action 
11 
