Given its location, the topoclimates and microclimates in the coffee producing areas of Nariño grant it a series of particular conditions adequate for coffee growing in terms of water availability, temperature, sunlight, and wind patterns.
Firstly, it is important to highlight the fact that the rugged mountains and steep slopes allow a rather fast changing variation in temperature throughout the day. The topographic conditions allow for a coffee production that would be impossible at such a great heights above sea level in other parts of Colombia or in other countries. The warm humid winds which rise up from the bottom of the valleys is what allow the coffee growers here to cultivate coffee plants at altitudes of up to 2300masl (7,500 feet).
Nariño only has one wet season a year, from Octoberto May, when theIntertropical convergence zonepasses over the region. This rainfall pattern is known as monomodal distribution (see Graph 1). The driest months: June, July and August, coincide with the trade winds from the south of the continent, characteristic in the region. The warm air currents in the daytime and cold nights allow greater condensation of the water vapor, which increases humidity, which, in turn, allows the coffee trees to survive the dryer months.
Graph 1 Typical precipitation patterns and rainfall cycles in Nariño
For coffee plants to flower, they need periods of continuous dry days of long or medium duration, and for those periods to be alternated with rain or brusque temperature changes. This, together with the monomodal rainfall pattern in the Nariño region, favor concentrated flowering during the first rains of September, which means that harvesting is concentrated between April and July of the following year. Graph 2 illustrates the rain distribution pattern and hydric balance throughout the year.
The soils of the Andes in the Nariño region are volcanic, which means that they provide the plants with substantial amounts of basic nutrients required for coffee production and, thus, contribute to the plants’ permanence and sustainability.
Chart 2. –Hydric Balance in the La Union region of the Coffee region.