1 Frn., 1899.] QUEENSLAND AGRICULTURAL JOURNAT. 127 
2. The application of mineral plant-food ingredients produces a better 
effect upon soils rich in humus than upon those deficient in this 
substance. 
3. The application of natural fertilisers gave the best results upon soils 
rich in humus; in this case the addition of artificial fertilisers had 
no effect. It should be mentioned, however, that potash and 
phosphoric acid always produce a beneficial effect upon the develop- 
ment of fruit. 
Dr. Dafert makes the following suggestions (regarding the fertilisation of 
older, i.e., bearing trees), which are based upon numerous observations :— 
J. Caution should be exercised in fertilising coffee with pure lime or 
magnesia, as the presence of these substances in large quantities will injure the 
growth. ‘Che maximum application lias not yet been definitely ascertained. 
2. It has been shown conclusively that, in order to grow coffee to the 
best advantage, it is best to apply the easily soluble fertilisers, especially the 
potash salts, at different times and in small doses, as the application of a large 
quantity at one time is not good for this plant. 
3. Organic fertilisers, not thoroughly decomposed, are apt to injure the 
plant. The greatest caution in this respect should be exercised in the use of 
animal substances, though the effect produced by vegetable substances also 
varies in proportion to the stage of decomposition. 
4, Sickly trees must}be made accustomed to easily soluble, strong ferti- 
 lisers gradualiy—z.e., it is advisable to begin with very small doses, which 
should be gradually increased, (This is recommended by Dr. P. Wagner for 
garden-plants and fruit-trees.) 
5. One-sided fertilisation—z.e., the application of only one ingredient— 
(a very popular method with many planters) has seldom been of practical 
benefit. ‘The application of nitrate of soda, for instance, almost always brought 
about a luxurious development of the plant, but the formation of fruit suffered. 
Tt is, therefore, advisable not to overlook the necessity of the simultaneous 
application of all the plant-food ingredients. 
6. No results are at hand regarding the question as to whether it is better 
to apply sulphates or chlorides, nitrate of soda, or sulphate of ammonia. 
To the question what kind of fertilisers should be applied, Dr. Dafert 
gives the following answer :— 
Natural, especially organic, fertilisers produced upon the farm (the quanti- 
ties of which should be systematically increased, wherever possible), and in 
addition artificial fertilisers, should be applied to coffee. Where diversified 
farming (with dairying) is absolutely impracticable, green manuring can be 
resorted to. 
The slowly soluble artificial fertilisers, such as Thomas’ slag, guano, bone- 
meal, &c., should be applied to rich soils, and especially where it is desired to 
supply the soil for several years. Easily soluble materials, such as acid phos- 
phate, nitrate of soda, sulphate of ammonia, and allof the potash salts, should, 
on the other hand, be applied when— 
1. It is desired to produce a rapid improvement in exhausted or 
weakened plantations, and toraise them to a state of the highest 
productiveness ; 
2. Coffee is to be cultivated on very poor but otherwise well-situated 
soils ; 
3. It is desired to correct some errors, as, for instance, deficiency of 
nitrogen in the case of poor sprouts, or deficiency of potash in case 
of insufficient fertility ; 
4, It is desired to counteract slight defects in climate (cool location). 
Dr. Dafert, in this connection, gives the following directions for the proper 
fertilisation of the coffee plant, in which an annual application of from 2:2 to 
8:8 Ib. of stable manure or compost to each tree is taken as a basis :— 
