Time for coffee and tea
Tea soil ecology and profile
It is essential to carry out an in depth profile of land before allocating land for growing tea; this is because good root growth and distribution is essential. Soil should ideally be analysed to a depth of one and a half meters. The tea plant can only weakly penetrate through stiff compacted soils. If a pan of clay or gravel is present, it offers an almost impenetrable barrier to tea plant root growth.
The depth of the roots that non-tea plants produce in an area is a good indicator as to whether tea will grow successfully there. A good deal of information can also be learned from the colour of the soil, with red coloured soils being much superior to black and grey ones. The redness of the soil indicates that their is a high state of oxidation of iron compounds, therefore if sub-soil is not rd it is indicative that impeded drainage is occurring.
Well drained, permeable soils are essential for the successful growth of tea. An example of the need for good drainage can be found at the Surma Valley. In this very deep V-shaped valley, deep open drains to a depth of 2 metres are required. In the rows of tea that are close to these drains the growth of tea is vigorous, this is a consequence of the superior soil aeration that takes place
It is important that land that is used for tea growth has good organic content. This can not always be conferred by the colour of the soil alone, for example many red loams have a very high organic content, whilst some black soils may be very low in humus content.
In conclusion, tea requires deep, acidic, well drained permeable soils. In the tropical tea growing countries these are typically provided by the red earthen soil.