568 QUEENSLAND AGRICULTURAL JOURNAL. [1 Drc., 1899. 
Commercial fertilisers may be divided into two classes : complete fertilisers 
and special or incomplete fertilisers, The former contain all the principal plant 
foods such as nitrogen, phosphoric acid, and potash, in varying proportions, 
whereas the latter contain only one or sometimes two of these essential elements. 
There are a large number of commercial fertilisers now on the market, a 
considerable proportion of which consist of the refuse of our meatworks and 
boiling-down establishments. These fertilisers consist mainly of blood, bones 
either fine or coarse, and dried refuse flesh. They vary considerably in their 
composition, owing to the source from which they are obtained, and are valuable 
on account of the nitrogen and phosphoric acid they contain, but as they 
contain practically no potash they rank as incomplete fertilisers. 
A good average sample of a bone and blood fertiliser should contain from 
6 to 7 per cent. of nitrogen, and from 12 to 14 per cent. of phosphoric acid, 
and be worth from £4 4s. to £5 per ton. The nitrogen is available, and is valued 
at 10s. per unit—that is to say, each per cent. of nitrogen present in the fertiliser 
is worth 10s. per ton. The phosphoric acid is insoluble, and is only worth 2s. 
per unit, and the rapidity with which it becomes available for plant food 
depends on the fineness to which it has been ground: thus, fine bonemeal ig 
rapidly acted upon by the carbonic acid in the soil, and rendered soluble and 
available for plant food, whereas coarse bones only become available slowly, and 
their action lasts over a considerable time. When quick results are required 
the manure should be ground as finely as possible; but for crops such as frnit 
trees, which occupy the soil for many years, it is advisable to have a proportion 
of coarse material mixed with the fine, so that the action of the fertiliser may 
be more lasting. The proportion of nitrogen and phosphoric acid in such 
manures varies considerably, and is dependent on the amount of dried blood, 
bone matter, or dried flesh present. When there is a large proportion of dried 
blood or flesh, then the nitrogen is high; but when there is a greater propor- 
tion of bone matter, then the nitrogen is lower and the phosphoric acid higher, 
Instead of mixing the blood, bones, &c., together, they are sometimes kept 
separate and sold as either bonedust or blood-manure. 
A good sample of bonedust should contain from 50 to 55 per cent. of 
bone phosphate, equal to 28 to 25 per cent. in round figures of insoluble 
phosphoric acid, and about 3 per cent. of nitrogen, and be worth from £4: to 
£4 5s. per ton. i 
A good sample of dried blood should contain 124 per cent. of nitrogen, and 
be worth £6 5s. per ton; and of nipho, 12 per cent. of nitrogen, worth £6 
per ton. 
Bonedust is most advantageously applied in conjunction with other 
manures, such as superphosphate, sulphate of ammonia, or sulphate of potash, - 
but if it is used alone it should be applied to the land some time before it is 
required ; otherwise it will not be available on account of its insolubility, but 
will tell more on the succeeding crops than to that to which it is applied. 
Blood and nipho, on the other hand, are in a readily available condition, and 
the crop to which they are applied derives a quick benefit therefrom. They can, 
therefore, either be applied at the time of planting the crop or can be used as 
a top dressing by being applied broadcast, and either harrowed, cultivated, or 
chipped in according to the nature of the crop to which they are applied. 
Neither blood nor nipho are complete fertilisers, as their manurial value depends 
entirely on the nitrogen they contain, and, before they can be made complete, 
must have phosphoric acid and potash added. 
A second class of commercial fertilisers are those special fertilisers con- 
taining only one element of plant food, usually either nitrogen or potash—such 
as sulphate of ammonia, nitrate of soda, sulphate of potash, muriate of potash, 
and kainit. 
Sulphate of Ammonia.—A. good sample should contain at least 20} per 
cent. of nitrogen, and be worth in round pees £10 per ton. This 
manure is very soluble, and consequently acts with great rapidity. It is used 
either as a top dressing by itself or is mixed with varying proportions of phos- 
phorie acid and potash to form a complete fertiliser. When used alone it 
