Coffee is the second most important beverage crop of India right after tea. The suitable geographical conditions required for the cultivation of coffee are discussed below
1. Physical conditions
(a) Climate: Coffee grows best in hot and humid tropical climate. Especially equatorial climate is favourable for coffee cultivation. [i] Temperature: An average temperature ranging from 20-25°C is ideal for coffee. [ii] Rainfall: An annual average rainfall of 150-250cm is required for growing coffee. [iii] Shade trees: Coffee plants are sensitive to direct sunlight. So trees with broad canopy are planted in between coffee plants so that they can provide shade.
(b) Soil: Fertile laterite soil of volcanic origin and red loamy soil are best suited for coffee cultivation.
(c) Type of land: Sloping highlands, especially foothills of mountains are ideal for coffee cultivation.
Laterite is both a soil and a rock type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by intensive and prolonged weathering of the underlying parent rock, usually when there are conditions of high temperatures and heavy rainfall with alternate wet and dry periods.
Tropical weathering (laterization) is a prolonged process of chemical weathering which produces a wide variety in the thickness, grade, chemistry and ore mineralogy of the resulting soils. The majority of the land area containing laterites is between the tropics of Cancer and Capricorn.
Thick laterite layers are porous and slightly permeable, so the layers can function as aquifers in rural areas. Locally available laterites have been used in an acid solution, followed by precipitation to remove phosphorus and heavy metals at sewage-treatment facilities.
Laterites are a source of aluminum ore; the ore exists largely in clay minerals and the hydroxides, gibbsite, boehmite, and diaspore, which resembles the composition of bauxite. In Northern Ireland they once provided a major source of iron and aluminum ores. Laterite ores also were the early major source of nickel.
The mineralogical and chemical compositions of laterites are dependent on their parent rocks Laterites consist mainly of quartz, zircon, and oxides of titanium, iron, tin, aluminum and manganese, which remain during the course of weathering. Quartz is the most abundant relic mineral from the parent rock.
Laterites are formed from the leaching of parent sedimentary rocks (sandstones, clays, limestones); metamorphic rocks (schists, gneisses, migmatites); igneous rocks (granites, basalts, gabbros, peridotites); and mineralized proto-ores;: 5 which leaves the more insoluble ions, predominantly iron and aluminum. The mechanism of leaching involves acid dissolving the host mineral lattice, followed by hydrolysis and precipitation of insoluble oxides and sulfates of iron, aluminum and silica under the high temperature conditions[9] of a humid sub-tropical monsoon climate.
Laterites vary significantly according to their location, climate and depth. The main host minerals for nickel and cobalt can be either iron oxides, clay minerals or manganese oxides. Iron oxides are derived from mafic igneous rocks and other iron-rich rocks; bauxites are derived from granitic igneous rock and other iron-poor rocks. Nickel laterites occur in zones of the earth which experienced prolonged tropical weathering of ultramafic rocks containing the ferro-magnesian minerals olivine, pyroxene, and amphibole.
Ayurveda context
Looking at the above natural biochemistry of the soil as in geography, and constitutional chemistry in terms of constitution of coffee it is a rich promotion of acids and hence a delicate good.
While it is abundant in cationic goodness, the strong association with chlorides and phosphates and sulphur yields a delicate susceptibility to alkalination which in presence of synthetic sugars and lactose has a susceptibility of producing OH- derivatives and esters which disintegrate to induce a mixed state of acid-alkalination, where ionic distribution, often Na+ plays a significant role.
This is delicate pinch on PITTA-KAPHA bond (Hydrogen Bonding) and a balance on either sides can shift the pH.
Therefore a limited use of Coffee, in the kapha pittaja kaal i.e. morning is recommended, however an evening pitta-vataja phase may skip and substitute with tea.
