1 Marz., 1902.] QUEENSLAND AGRICULTURAL JOURNAL 157 
Every intelligent horticulturist is aware of this fact, and acts accordingly, 
being guided in the application of fertiliser by the analysis of the ash of such 
plants and trees as he cultivates. 
It is on this principle and on this basis that the special fertilisers are 
manufactured, each containing the particular ingredients needed by the 
particular plants to which it is intended to be applied. One may need a larger 
amount of ammonia than the soil naturally furnished, another more potash, 
another more nitrogen and phosphates. When these special fertilisers are 
made by honest manufacturers they are very valuable aids to the farmers and _ 
fruitgrowers. 
Analysis shows that the ash of the orange tree and fruit contains a large 
percentage of potash, lime, and phosphoric acid, besides smaller quantities of 
other mineral ingredients. Hence, these are substances, conjoined with 
sufficient vegetable matter to retain moisture, that the orange-grower must feed 
to his trees. 
And now how are these to be obtained ? Easily, and by every man who 
chooses, for they are all about him in profusion, needing only to be utilised by 
a provident and thrifty hand. 
The analysis of a soil may show lime to be needed, and lime is forthwith 
applied, and without effect, because powerless to work alone. Combine it with 
humus, which, as everyone knows, is simply decayed vegetable matter, and then 
its effect will be quickly visible. 
Here is one of the many proofs that there are two distinct classes of 
manures, one serving as the actual food of plants, the other assisting in pre- 
aring that food by combining with the substance in the soil and bringing it 
into a form that the plants can assimilate, or by changing such as would be 
inimical to vegetable life. Thus, for instance, when we apply lime to a newly 
broken piece of land which is mucky, we say that the lime has sweetened it, 
because its action on the carbonic acid contained in the muck is such as to 
change, by combination, that which would otherwise be hurtful to vegetation 
and helps to transform it to valuable manure. 
Jn applying fertilisers to trees, the latter should be treated rationally. A 
surfeit of rich food will derange the animal system, and so it will the vegetable. 
Too large quantities of manures, rich in nitrogen, for instance, will cause dieback 
and fungoid diseases. 
While the trees are young and in rapid growth they will bear heavy 
fertilising, just as a growing child will eat more in proportion than an adult ; 
but if the system of high fertilising is continued after they have arrived at the 
bearing age, eight or ten years, it will almost invariably retard their fruiting, 
as too rich a soil has a tendency to make wood rather than fruit. There- 
fore, after the seventh year the quantity of fertiliser should be gradually 
lessened, and only enough used to keep the tree in a healthy slow-growing 
_ condition. 
In fertilising for young trees nitrogen should be present in larger quantities 
than for bearing trees, the latter requiring more potash, phosphoric acid, and 
other kindred ingredients. Yellowish leaves indicate deficiency of nitrogen in 
the soil; dark-green leaves show that there is plenty of it. 
Finally, do not lose sight of this fact: Of the three ingredients mentioned 
either one or two are deficient; so, also, is lime often on a soil requiring 
fertilising. Now, you cannot make up for the want of potash by increasing the 
uantity of nitrogen, neither will an excess of potash make up for a deficiency 
in phosphoric acid. If any one or two of these substances is wanting, the soil 
will not produce abundant crops, and you must see that the necessary ingredient 
is supplied. 
Suppose that PHosproric Actp is wanting, how are you to supply it? 
You have seen that you can do so by using bone-ash, bone-meal, phosphatic 
guano, Thomas’ phosphate, or superphosphate. 
