1. Land Preparation:
After selection of plantation site, the land is cleaned off of jungles, stubbles, stones, gravels, grasses and unwanted vegetation. Trees are ring barked uprooted, and remove away from the site. Old stumps, tree roots, trashes should not be burnt in-situ as that may spoil the soil structure and micro-flora or fauna. The land is then opened up for cultivation.
After clearing, the land is laid out in accordance to the topo-sequence by making roads, paths and drains. High tillah land with 30% slope is subjected to soil erosion. Moreover, the exposed tillah may cause wind erosion. Erosion can also occur even when the land is only sloping gently. Teas grown on these sites are subjected to too much evaporation of dry winds. After 5 years of planting, erosion is less serious as a thick mat of leaf and pruned branches under tea absorb the run-off. Proper soil conservation measures are taken by making drains, contour paths and contour boxes.
The cut-off drains are dug across the top tillah plantation to prevent rain water running down the hill ceusing soil erosion. The entire area of proposed plantation site is surveyed using Dumpy level /Ceylon Tracer/ Spirit level. The contour map is drawn. Accordingly, the contour paths, 50-60m.wide, are made in a gradient of 1:500 and the inter-contour distance is about 9-15m.
The drains are cut V-shaped basin type, 8-10m. apart for heavy soil, 10-12m. apart for medium soil and 12-15m. apart for sandy soil. During rainy season, the flow of run-off may be checked by making V-shaped Contour Box, 50-60cm. long, 15-20cm. wide and 45-50cm. deep along the path. If the plantation is to make in the valley bottom (i.e. Kunchi area between hills), the drainage system with appropriate sub-drains is developed.
2. Plantation techniques:
There are various types of planting system, viz. Triangular, Square and Hedge. In Bangladesh tea, the single hedge planting is in vogue. The spacing distance is 120 cm.x 60 cm. (4 X 2).( Kibria, etl. 1988.) This type of planting system is found to be superior to others in respect of quick coverage, highest plant density per unit area and convenience for inter-cultural operations. The population load per unit area may be calculated by using the following formula:
Area
N= ---------------- When, N = Number of plants
g x d g = Line to line distance
d = Plant to plant distance in straight line
it is thus estimated that about 13450 plants/ha are required for tillah plantation using spacing 120 cm. x 60 cm., while 10760 plants for flat plantation using 120 cm. x 70 cm.
In field practice, the staking and lining is done simultaneously prior to planting green crops or shade. After staking, the digging of planting pits is done along the line. The size of the planting pits varies for the clonal tea seedling tea. For clonal tea the pit size is 25-30 cm. wide x 30-35 cm. deep, while for seedling tea, 25-30cm. wide x 40-45cm. deep. The excavation of soil from the pit is done in sequence. The top soil is cut 20cm. deep x 30cm. wide (across) and kept separately. Then the lower sub soil is dug 15cm. deep x 30cm. wide for clonal plant of 35cm. for seedling tea.( Mandi, 1971)
