Soil and water requirements of coffee
Best coffee production comes on well-drained and well-aerated soils rich in nutrients and humus content.
It is best to avoid heavy clays and highly leachable sands or gravels.
A soil’s texture and structure must allow a large root zone to develop so that the plant can still access water during the dry season. Rooting depth depends on soil condition. However, tap roots extend to a depth of around 3-4m below the soil surface. They are supported by lateral roots, which stretch some 2m out from the trunk.
However, 80% or more of the feeder roots are in the first 20-30cm depth of soil, up to a 1m radius out from the trunk.
As a result, most fertilizer is applied onto this narrow rooting zone in order to maximize uptake.
Good drainage is essential to allow excessive rainfall to move away from the root zone. The preferred soil pH for optimum production is 5.2 to 6.3. However, in practice coffee is grown at pHs below 4.0 to above 8.0.
Liming is necessary at lower pH levels to ensure good nutrient availability.
Mulching is widely practiced, with growers regularly returning composted berry pulp to the plantation to conserve moisture, boost organic matter and recycle nutrients. Careful use of mulches is essential in young seedlings to avoid problems of scorch from ammonium in poorly composted mulches.
Reasonably accurate water requirement estimates for coffee are crucial because too little water can substantially reduce growth without wilting or other visible signs of moisture stress. Water use by coffee is most usefully expressed as a ratio of crop evapotranspiration to the reference evapotranspiration (ETc/ET0), also known as the crop coefficient (Kc).
The benefits of irrigation can only be achieved in all its fullness when irrigation system is used with criteria management that result in water applications quantities compatible with the needs of consumption culture. A good irrigation management strategy is essential to save water without threat the crop yield. Furthermore, the determining the exact moment to make the Irrigation is one of the key steps to rationalization of water management. Accurate estimates of needs water in the coffee are essential since lack of water can reduce more significantly the plant growth without showing the same signs of wilting or any other symptom visible.
