Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Nutrient Status of Soil and Regenerated Garjan (dipterocarpus Turbinatus Gaertn.) Seedlings in Dulahazara Garjan Forest, Cox’s Bazar, Bangladesh

Huda, M. K.*
Department of Botany, Chittagong University, Chittagong - 4331, Bangladesh

Chowdhury M. A. M.
Department of Botany, Chittagong University, Chittagong - 4331, Bangladesh

Abstract/ Executive Summary:

Soil: Plant nutrient status in naturally regenerated garjan (Dipterocarpus turbinatus Gaertn.) seedlings of 3, 9, 15, 21, 27 and 33 months old were studied in twelve stands of three sites on late and early monsoon during 1994 to 1995 in Dulahazara garjan forest of Cox’s Bazar forest division. Soil samples were collected from two profiles (i.e. top soil and sub soil) of twelve stands in three sites. Soil moisture content, pH, texture, electrical conductivity, cation exchange capacity, organic carbon, total N and available P, K, Ca, Mg, Mn and Fe were determined. Soils were found to be silty loam to sandy loam with an average pH of 5.06. The average values of organic carbon and cation exchange capacity were 0.74% and 6.23 meq/100g respectively. The soils were poor in total nitrogen (689 µg g^-1) and the average values of available mineral nutrients such as P, K, Ca, Mg, Mn and Fe in soil were 3.15, 53, 40, 47, 36 and 0.94 µg g^-1, respectively. The soil in site -S2 appeared to be more fertile than those of site-S1 and site-S3. The average values of N, P, K, Ca, Mg, Mn and Fe in leaf- bud were found to be 1.80, 0.13, 0.94, 0.72, 0.23, 0.06 and 0.014% respectively. Leaf-bud nutrients showed a marked variation both with seasons as well as ages. Leaf-bud of late monsoon contained higher concentrations of P, Mg and Ca compared to leaf-bud of early monsoon which contained higher concentrations of N, K and Fe. Nutrient cycling in soil: leafbud system of regenerated garjan seedling of 3-33 months old varied with seasons and ages. The present study reveals that concentrations of Mn were significantly correlated between leaf-bud and soil whereas P showed the negative correlation indicating that in spite of low quantity of P in the soil, leaf bud had higher quantity.

Keywords: Garjan seedlings, Nutrient status, Seedling ages, Soil.

Location: Department of Botany, Chittagong University, Chittagong - 4331, Bangladesh

Start Date:

End Date:

Program Area: Development of Host and Medicinal Plants

Commodity: Gorjon, Soil fertility

Objectives:

The present investigation was undertaken to study the nutrient status of garjan seedlings leaves of different ages that will be helpful for understanding the nutrient cycling pattern of the plants. Similarly evaluation of nutrient status of the soil of that area will indicate the feasibility and suitability of soils for growing garjan. Thus nutrient cycling patterns in soil: plant system of naturally regenerated garjan seedlings of varying ages in natural garjan forest floor of Cox’s Bazar will explore a new dimension of natural garjan regeneration maintaining harmony with edaphic factors.

Methodology:

The nutrient status of the terminal leaf-bud of the regenerated seedlings of different ages and the nutrient content of the soils surrounding the roots of the regenerated garjan (Dipterocarpus turbinatus Gaertn.) seedlings were determined to account for the nutrient cycling in the soil-plant system of the regenerated seedlings. Regeneration status and density of garjan seedlings of the same area and age determination of garjan seedlings were investigated. Study area: The study area (20° 41' - 20° 44 ' N, 92°4 '-92°6' E) is situated on the eastern hilly side near the coast of Bay of Bengal, 72 km south of the port city Chittagong. The forest area lies 2 to 6 m higher from the surrounding plains. The annual rainfall in this area is 3499 mm and most rainfall between May and September. The mean annual temperature is about 25° C with mean monthly temperature varying from 15.5°C (January) to 33° C (May). The humidity is high (86- 96%) except in the dry season (November to March). In the winter season (November to March) when the rainfall is low, sometimes there are heavy dew and thick mist. The topography is ragged. The terrain in the hills is extremely irregular. Most of the area is situated between 15.2m and 45.7m above the sea-level. The soil varies from loam to sandy loam on hilly ground. The sandy soil is often impregnated with iron giving a reddish or yellowish tinge. The soil is very porous and sandy in the Dipterocarp forest (Das, 1980). Selection of site: The vegetation of the area consists of a lower-storey undergrowth comprising 180 species (Islam, 1996), a middle-storey of planted garjan of 45-50 years old, and an above storey of tall, giant and matured garjan trees of more than 100 years old which are naturally regenerated and endemic to this area. Dulahazara garjan forest of Cox’s Bazar district was selected as experimental field on the basis of abundance of regenerated seedlings of various ages on almost the same type of topography in three studied sites namely Site-S1, Site-S2 and Site-S3. Each site consisted of four stands those were selected randomly from the laid grid of the vegetation. Collection, processing and analyses of soil: Soil samples were collected randomly from the top soil (1-25 cm) and sub/ sub surface soil (26-50 cm) at four different places of the stand. Four samples were considered as four replicates of a stand. On the other hand, four samples were also collected for one stand and made it composite for the stand. Soil moisture content was determined gravimetrically. Then soil samples were dried in the open air and ground. Samples passed through a 2 mm sieve and then stored in a cool dry place in the laboratory for analyses. Soil texture was determined by Bouyoucos Hydrometer Method and named according to soil texture class triangle (USDA, 1951). Soil pH and electrical conductivity were measured based on 1:2 soil/water suspension using calibrated digital pH meter and conductivity meter respectively. Organic carbon was determined by the Modified Oxidation Method of Walkley & Black (1934). Total nitrogen (N) and Cation exchange capacity (CEC) of soils were determined by the MicroKjeldahl Distillation Method (Jackson, 1958). Available phosphorus (P) was extracted using 1M ammonium acetate (pH 7.0?.05) and determined by Spectrophotometer (blue colour method of Jackson, 1958). Available potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn) and iron (Fe) were extracted using 1M ammonium acetate (pH 7.0). K and Ca were measured by flame photometer and Mg, Mn and Fe were determined by Atomic Absorption Spectrophotometer. Collection, processing and analyses of leaf buds: Terminal leaf-bud of naturally regenerated garjan seedlings (first three leaves with unfold bud) of different ages (1, 2 and 3 years) were plucked randomly from 3-5 seedlings of each stand of three different sites. The terminal leaf-buds were collected on two different periods (late monsoon and early monsoon) at 6-month intervals during the study period. The studied seedlings were grouped into 3 and 9 months old (1 year), 15 and 21 months old (2 years) and, 27 and 33 months old (3 years) which resulted in the seedlings being ranked into 6 different ages (Huda, 1996; Huda et al., 1997). Samples were air dried at room temperature, ground and were extracted by Sulfuric-peroxide (H₂SO₄ - H₂O₂) digestion mixture (Allen et al., 1986). N (Micro-Kjeldahl Method), P (Spectrophotometer), K, Ca (Flame Photometer) and Mg, Mn, Fe (Atomic Absorption Spectrophotometer) were determined. Statistical analyses were performed following standard methods and Microsoft Excel.

Source of Information: Jahangirnagar University J. Biol. Sci. 7(2): 79-88, 2018 (December)

Article Link (Online Journal):

Funding Source:

Budget:

Total Budget (Tk.) :

Achievement/Findings:

On the basis of the above mentioned results, it is concluded that overall nutrient status of soils in different sites of the Dulahazara garjan forest was moderately low and the different nutrients in leaf-buds of successfully regenerated garjan seedlings fluctuate with seasons and age of seedlings. In the soil: leaf-bud system of regenerated garjan seedlings, Mn concentration in leaf-bud is associated with concentration of Mn in soil whilst P concentration in leaf-bud is inversely associated with the status of P in soil.

Knowledge Management: Journal