Are you Jusop S?

Claim your profile

Publications (2)0 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Problem statement: The tropical rain forests in Southeast Asia have been characterize by several researchers. However empirical data on soil characteristics under degraded forest land in tropical rain forest and rehabilitated program are limited. A study was conducted to evaluate the soil orphology, mineralogical and sesquioxide properties of a rehabilitated degraded forest land (19 years after it was planted with various indigenous species) in comparison with an adjacent secondary forest. Approach: Soil samples were air-dried and pass through a 2 mm sieve. Soil morphology was determined based on field observation. The non-crystalline (amorphous) of Al, Fe and Si oxides and hydroxides (Alo, Feo and Sio) were extracted with ammonium oxalate while the Dithionate-Citrate- Bicarbonate (DCB) method was used for extracting (crystalline) the Al, Fe and Si oxides and hydroxides (Ald, Fed and Sid). The concentrations of extracted Al, Fe and Si were determined by atomic absorption spectroscopy. Mineralogical compositions were identified by X-ray diffraction method. Results: The A-horizon of secondary forest was darker and thicker than that of the rehabilitated forest. Root mat at the secondary forest was well-developed compared to the rehabilitated forest. The clay minerals were dominated with kaolinite and illite to a lesser extent of goethite and hematite accompanied with low values of activity ratio of Al and Fe oxides and hydroxides, indicating that the soils were highly weathered. Conclusion/Recommendations: The difference between rehabilitated and secondary forests was root abundance where secondary forest had most. Good root penetration in the secondary forest indicates that the soil texture there was not heavy. Soils in the rehabilitated and secondary forests were strongly weathered (high presence of kaolin minerals), but the low presence of sesquioxides suggests that they are yet to reached the ultimately weathered phase. The soil properties in terms of morphology, sesquioxides and clay minerals should be taken into account for better management of forest rehabilitation program in tropical regions.
    American Journal of Environmental Sciences. 01/2010;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Problem statement: The soil properties of tropical rain forest in Southeast Asia have been characterized by several researchers; however empirical data on soil characteristics under rehabilitation program are still limited or even lacking. This research is important to determine the soil physical and chemical properties of a rehabilitated degraded forest land 19 years after planting with various indigenous species in comparison with adjacent secondary forests and to elucidate the soil fertility status in rehabilitated and secondary forests by using Soil Fertility Index (SFI) and Soil Evaluation Factor (SEF). Approach: Soil samples were collected from both locations which were rehabilitated forest and secondary forest (Nirwana forest) at University Putra Malaysia, Bintulu Sarawak Campus. The plot size of each experimental site was 20×20 m. An auger was used to take soil samples from two depths, namely 0-10 and 10-20 cm. For soil profile, the soil samples were collected from different depths up to 100 cm according to the soil horizons. The samples were air-dried, homogenized and sieved to pass a 2 mm mesh sieve for further analysis. The physical analysis consisted of bulk density and soil moisture content. For chemical analysis, soil acidity, soil organic matter, total organic carbon, available P, exchangeable Al, exchangeable ammonium and nitrate, exchangeable cations (Ca, Mg, K) and Cation Exchange Capacity (CEC) were determined. The soil fertility status was determined based on SFI and SEF values for both rehabilitated and secondary forests. Results: The bulk density of the rehabilitated forest ranged between 0.70 and 1.29 g cm-3 and that of the secondary forest was 0.64-0.76 g cm-3. The soil moisture content of the rehabilitated forest was 23.31-51.03% while that of secondary forest was 41.06-41.49%. The range pH (water) of the rehabilitated forest was 4.5-5.0 and that of the secondary forest range was 4.2-4.3. Furthermore, the content of SOM in the rehabilitated forest was 2.5-5.8%. On other hand, the range for the secondary was 4.1-4.6%. The exchangeable Al of the rehabilitated forest was 0.8-2.5 cmolckg-1 and that of the secondary forest was 1.6-1.7 cmolckg-1. The CEC of the rehabilitated forest was 1.4-11.8 cmolckg-1, while that of the secondary forest was 4.3-4.5 cmolckg-1. Based on SFI and SEF values, the secondary forest had a lower fertility status compared to the rehabilitated forest. Moreover, the SEF value of the secondary forest was below 5, while some of the plots of rehabilitated forest had the SEF values greater than 5. Conclusion: It can be concluded that both rehabilitated and secondary forests have significant differences based on selected physical and chemical properties. Moreover, the soil fertility status at rehabilitated plots was comparatively higher than secondary forest indicating a good potential of ‘Miyawaki’ forest rehabilitation technique in rehabilitating and replenishing soil fertility status of degraded forest land.
    American Journal of Applied Sciences. 01/2010;