Preparing the Plantation. Before transplanting time has come, the plantation itself has been made ready to receive the young plants. Coffee plantations are generally laid out on heavily wooded and sloping lands, most often in forests on mountainsides and plateaus, where there is an abundance of water, of which large quantities are used in cultivating the trees and in preparing the coffee beans for market. The soil most suitable is friable, sandy, or even gravelly, with an abundance of rocks to keep the soil comparatively cool and well drained, as well as to supply a source of food by action of the weather. The ideal soil is one that contains a large proportion of potassium and phosphoric acid; and for that reason, the general practise is to burn off the foliage and trees covering the land and to use the ashes as fertilizer.
In preparing the soil for the new plantation under the intensive cultivation method, the surface of the land is lightly plowed, and then followed up with thorough cultivation. When transplanting time comes, which is when the plant is about a year old, and stands from twelve to eighteen inches high with its first pairs of primary branches, the plants are set out in shallow holes at regular intervals of from eight to twelve, or even fourteen, feet apart. This gives room for the root system to develop, provides space for sunlight to reach each tree, and makes for convenience in cultivating and harvesting. Liberica and robusta type trees require more room than arabica. When set twelve feet apart, which is the general practise, with the same distance maintained between rows, there are approximately four hundred and fifty trees to the acre. In the triangle, or hexagon, system the trees are planted in the form of an equilateral triangle, each tree being the same distance (usually eight or nine feet) from its six nearest neighbors. This system permits of 600 to 800 trees per acre.
Shade and Wind Breaks. Strong, chilly winds and intensely hot sunlight are foes of coffee trees, especially of the arabica variety. Accordingly, in most countries it is customary to protect the plantation with wind-breaks consisting of rugged trees, and to shade the coffee by growing trees of other kinds between the rows. The shade trees serve also to check soil erosion; and in the case of the leguminous kinds, to furnish nutriment to the soil. Coffee does best in shade such as is afforded by the silk oak (Grevillea robusta). In Shade in Coffee Culture (Bulletin 25, 1901, division of botany, United States Department of Agriculture), O.F. Cook goes extensively into this subject.
The methods employed in the care of a coffee plantation do not differ materially from those followed by advanced orchardists in the colder fruit-belts of the world. After the young plants have gained their start, they are cultivated frequently, principally to keep out the weeds, to destroy pests, and to aerate the earth. The implements used range from crude hand-plows to horse-drawn cultivators.
Fertilizing. Comparatively little fertilizing is done on plantations established on virgin soil until the trees begin to bear, which occurs when they are about three years of age. Because the coffee tree takes potash, nitrogen, and phosphoric acid from the soil, the scheme of fertilizing is to restore these elements. The materials used to replace the soil-constituents consist of stable manure, leguminous plants, coffee-tree prunings, leaves, certain weeds, oil cake, bone and fish meal, guano, wood ashes, coffee pulp and parchment, and such chemical fertilizers as superphosphate of lime, basic slag, sulphate of ammonia, nitrate of lime, sulphate of potash, nitrate of potash, and similar materials.
The relative values of these fertilizers depend largely upon local climate and soil conditions, the supply, the cost, and other like factors. The chemical fertilizers are coming into increasing use in the larger and more economically advanced producing countries. Brazil, particularly, is showing in late years a tendency toward their adoption to make up for the dwindling supply of the so-called natural manures. As the coffee tree grows older, it requires a larger supply of fertilizer.
The Famous Boekit Gompong Estate, Near Padang, on Sumatra's West Coast
Showing the healthy, regular appearance of well-cultivated coffee bushes, twenty-six years old. Also note the line of feathery bamboo wind-breaks
Pruning. On the larger plantations, pruning is an important part of the cultivation processes. If left to their own devices, coffee trees sometimes grow as high as forty feet, the strength being absorbed by the wood, with a consequent scanty production of fruit. To prevent this undesirable result, and to facilitate picking, the trees on the more modern plantations are pruned down to heights ranging from six to twelve feet. Except for pruning the roots when transplanting, the tree is permitted to grow until after producing its first full crop before any cutting takes place. Then, the branches are severely cut back; and thereafter, pruning is carried on annually. Topping and pruning begin between the first and the second years.