126 QUEENSLAND AGRICULTURAL JOURNAL. [1 Frs., 1899. 
humus-producing substances alone does not answer the plant-food require- 
ments of the coffee plant. The application of mineral fertilisers becomes 
absolutely necessary whenever a soil has been under cultivation for some time, 
and its natural supply of plant-food has become depleted. 
The plant-food requirements of the coffee plant have been thoroughly 
investigated by Dr. F. Dafert,* Director do Instituto agronomico do estado de 
Sao Paulo, Campinas. Asa result of his extensive studies, he compiled the 
following figures, giving the plant-food requirements of the average coffee-tree 
upon an average soil :— 
Lime. Magnesia, Phosphoric}Acid. Potash. Nitrogen. 
In the Ist year a OHOGYS 0-019 0'119 0013 0215 
i yp aa o, ee Os253 0-089 04383 0120 0271 
ee ore we 8484 1150 6°292 0°653 G6:345 
jee Athy os .-. 9030 L574 9°805 1:041 10°674, 
oy spy «ee 12°4.25 3910  21°6738 27390 187106 
5 yy WORA ... 11°268 3619 16°011 1778 ~=—-18'066 
Wiest thee ... 4188 1288 6056 0663 5°538 
The roots, stems, and branches were carefully weighed, and the following 
quantities of coffee beans used as a basis for the yields :— 
4 year old tree .. ot ies oD 2. 3'O274 02. 
SIStv Set ah eee tre Sa EACETAD 9 
10 ” 2S? tee eee eee see se. 9072/40. ” 
40 ” 799 eee 70548 » 
When we consider, however, the fact that in tolerably well-cared for 
gardens an abundant use of fertilisers results in a correspondingly increased 
yield, requiring proportionately larger quantities of plant-food for the formation 
of wood and leat, it becomes evident that the actual plant-food requirements 
of this plant are considerably greater. Dr. Dafert therefore recommends 
the following quantities of plant-food ingredients to be applied to each tree per 
annum :— 
Phosphoric Acid. Potash. Nitrogen. 
Trees 0O—4 years old ... 0040 oz, 0°378 0°158 
» SFR 5p gy oo WHE ,. 1:231 0571 
9 BED gy x = OE CC, 0°734 0°462 
3) OPW gy ae ONL 0:488 0:081 
In this way the formation of wood and leaf necessary for the rapid 
development of the tree is promoted, in the first few years, by extensive 
nitrogen and potash fertilisation, and later on the fruitis aided in its formation 
and development by larger quantities of phosphoric acid and potash. It is 
therefore apparent that the principles laid down for other fruit-bearing trees 
(apples, pears, oranges, lemons, &c.) apply also to coffee. 
As a complete absorption of the plant-food ingredients contained in the 
fertiliser cannot be expected, it is absolutely essential that the quantities applied 
should be increased in proportion to the nature and condition of the soil. 
Fertilising experiments with coffee plants are neither so numerous nor 
satisfactory as to enable us to draw correct conclusions regarding the various 
questions involved in the proper fertilisation of the plant. 
Several years ago, Dr. Dafert inaugurated some strictly scientific experi- 
ments; they are not yet far enough advanced, however, to show the effect of the 
various plant-food ingredients upon the yield, although striking differences in 
the development of the young plants can easily be recognised at this early date. 
1. The presence of humus-forming substances (stable-manure, compost, 
coffee-shells, &c.) produces a beneficial effect, although, when used 
in combination with artificial fertilisers, their availability becomes 
roneera bly increased, in proportion as the soil itself is deficient in 
umus. 
* “Landwirthschaftliche Jahrbiicher,” 1894, p, 27, and Dr. Dafert, “ Bemerkungen iiber 
rationelle Kaffeekultur,” Berlin, Parey, 1896, i 
