Bamboos are giant, woody, tree-like grasses – with a long history of exceptional versatile and widely used resource. India possibly has the world’s richest resources of bamboo, with 130 species occurring over an area of 10.05 million hectare, which is about 12.8% of the total forest area.
The diverse bamboo in the natural habitat are dwindling, due to over – exploitation, shifting cultivation practices and extensive forest fires. Sustained availability can be ensured only by plantations. However, we know very little about several aspects of this fascinating plant. Research has increased rapidly in recent years. The present work is aimed at providing information on Silviculture and management of plantation bamboo forests, yield and economic aspects.
The study area is located at Kallipatty (Tamil Nadu) between 11°28′ and 12°E latitude and 76°59′ and 77°47′ N longitude with an altitude of 540 msl. The mean temperatures are 31°C and mean annual rainfall is about 600mm. This area has red soil, with pH ranging from 7.4 and 7.8. The total soil nitrogen, phosphorus and potassium were 3800, 360 and 3600 kg ha-1 respectively.
Nursery Management Practices:
Seedlings obtained from tissue culture technique were used for establishing plantation. The large sized polythene bags of size 20 x 30cm were filled with soil, sand and manure in the ratio 2:1:1. The clumps of seedlings were planted in each polythene bag. Seedlings were kept in polythene bags for one month. A nursery area of 10m x 5m was prepared in the field and filled with a mixture of soil and sand (3: 1).
The seedlings of about 7cm height were removed from the polythene bags and 25 seedlings were planted in 1 m2 of raised nursery bed at equal distance. Nursery beds were provided with a thatch to protect seedlings from direct sunlight.
Transplanting:
The seedlings in nursery were up-rooted carefully and transplanted to 45cm3 pits in the fields at a spacing 6m x 6m. One week prior to planting, the pits were treated with 0.01% aldrex and 0.05% bavistin to prevent termite and fungal attack respectively. The planting was completed before the monsoon got fully active.
The transplanted seedlings were watered twice a day once at 8 am and another at 4 pm, till the soil get saturated. Weeding was done as and when required. After one year, the plantation was adequately irrigated at 15 days interval, care was taken to avoid water logging. The plantation was protected against damage by rodents, grazing and browsing animals.
Growth and Production of Culms:
All the transplanted seedlings produced rhizomes. The clump buds emerge with the onset of early rains and grow rapidly. The productivity of bamboo was assessed by the number of new clump produced annually. At a given site, the production of new culms mostly depends on the culms of the previous year, the degree of congestion and the clump age. Seedlings of Bambusa bambos produced only 5 culms per clump in the first year after planting.
The average number of culms increased in the subsequent years to 8. 12. 14, 16 and 17 per clump. Culms emerging in the first year were short (1.4 m) in length and small in diameter (2.3 cm). Culms produced in subsequent years were distinctly taller and thicker.
Productivity:
The mean grand total per culm tripled in years 1 and 2. Increments then declined from the end of year 2 to the end of year 6, biomass rose from 17.5 kg to 70.1 kg. The total standing biomass t/ha-1 was calculated using data on the density of the bamboos of different ages. Dry matter production increased progressively and reached 286.6 t/ha-1 by the sixth year. In comparison with earlier results it was observed that productivity was higher in the present study.
Felling Cycle and Economics:
The pulp and paper making characteristics of one to six year old Bambusa bambos were investigated. The study revealed that, in plantation bamboo, although no appreciable change in chemical composition of pulp could be detected with increasing age, the bamboo species reached maturity during the first year of growth. Hence, one to six year old culms can be used as raw material for pulping.
However, in order to get a higher annual yield of culms in the subsequent years it is recommended that a 36 months cutting cycle is ideal for pulping purposes. However, Bose et al., (1998) suggested cutting cycle of 21 months for muli bamboo (Melocanna baccifera) with regards to yield gain, biennial felling cycle has also been observed to give maximum yield and superior quality in the case of Dendrocalamus strictus. Chen et al. (1985) also concluded from the study on ten bamboo species that the bamboos should not be older than 36 months for chemical utilization if, practices of cultivation and rotation were considered.
Economics:
It can be concluded that, the Bambusa bambos plantation is not profitable until the end of three years. However, after this period, it is noticed that cost-benefit-ratio (B/C) exceed 1.0 showing good financial results, at the age of six year.