Fire has become a great threat to Indonesian rainforest. However, informative data quantifying the effects of wildfire on the soils are still limited. We have been studying the leftover effect of forest fire on characteristics of Indonesian Ultisols. Current experiment evaluated physico-chemical characteristics of soils under different ecosystems with different wildfire history. Seven sites, which could be grouped into unburnt sites (conservation forest (CF), Pine forest (iF), Acacia mangium plantation (AM), and home garden (HG)) and burnt sites (Acacia mangilan plantations bumt in i995, L997, and 1998) referred as AM-b95, AM-b97, and AM-b98, respectiveiy, were sampled. Organic layei was found in CR PR and AM but not in any other sites. Morphologically, soils of unbumi sites had darker A horizon than those of burnt sites. In spite of lack of significant differences, bulk density decreased with increasing period after fire, indicating the recovery process. Although the upper layer oi the bumt soils was physically harder than that of the unbumt soils, soil hardness did not aipear to be a limiting factor for plant growth. Soil in the unbumt sites was chemically more acid but contained mqre organic C and N than that in the bumt sites. Surface soil of PF, AM-b98, and HG had much higher exchangeable Ca than any other sites. However the CEC was low across the study sites, irrespectivi of the high clay content. Available P was also low, and conelated with high Al solubility. Crysialline Al, Si, and Fe contents of all soils were higher than amorphous Al, Si, and Fe oxides. ZpC values were low across the study sites. However, higher negative charge generated by organic matter had resulted in lower ZPC values at the surface layer as compared with the subsurface Lyer. Although soils in the unbumt sites showed a better physico-chemical potential than the bumt site;, in general Ultisols in the study sites had undergone strong weathering and showed low natural fertility potential.

Kungkilan River is under the administration of West Merapi Sub-district, Lahat, which is potential to degrade its water quality, resulted from the activity of coal mining. This research is aimed to analyze the quality of water in Kungkilan River in every segment of coal mining campany and proposing a recommendation of management strategy of river pollution. This research applied the descriptive analysis with the quantitative approach using sample survey method. The analysis of the recommendation of management strategy of river pollution was conducted through SWOT method. The sample of water in Kungkilan River was collected from 5 stations. The sample of waste water was collected from 7 spots of Sludge Sedimentation Pond of the coal mining campany. It was collected during the dry and rainy season. It can be concluded that the quality of water in Kungkilan River has been degrading right after streaming through the area of coal mining. In the dry season, each segment meets the calculation of the capacity of water pollution for TSS parameter, while in the rainy season, segment IV exceeds the capacity. In the rainy season, the quality of water in Kungkilan River in the station S-02, S-03 and S-04 encounters a self-purification process, while in Station S-05 is in the condition of moderate pollution. Based on hose finding, it is recommended that the management strategy of Kungkilan River pollution can be conducted through having research on the determination of water classification and the capacity of water pollution in Kungkilan River and supervising the quality of water periodically and continually; improving the frequency of supervision by PPLH/PPLHD personnel and functionally; moving the water disposal canal to other spots and conducting vegetation; regulating law administratively, both civil and criminal law, to the companies violating the regulation of water pollution management; and benefitting the CSR program of the company.

This work reports the modification of West Java natural bentonite as an effective adsorbent for rhodamine B dye. The modification was finished by sodium intercalation at room temperature to get low-energy preparation. Characterization of bentonite-modified adsorbent was used SEM, XRD, FTIR, and BET analysis. The material pore size and surface area were increased by 0.303 nm and 178.710 m2/g on Na-bentonite. The adsorption mechanism conformed well with the Freundlich isotherm model and pseudo-second-order kinetics equations. The adsorption process by thermodynamic analysis was endothermic and advantageous. Under the optimum condition of pH 6 (confirmed by pHpzc), initial dye concentration of 125 mg/L, and the adsorbent dosage of 0.09 g for 65 minutes, the Na-bentonite has a larger adsorption capacity (Qm) of 142.86 mg/g, while the different adsorbent dosages of 0.11 g for 75 minutes, the adsorption capacity of natural bentonite (Qm) reaches 140.85 mg/g. This work provides a method for establishing a low-energy preparation adsorbent of bentonite-based on Na intercalant as a low-cost and valuable adsorbent for waste dye removal.

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<p>Sugarcane harvest results in plant residues, consisting of leaves, stems and roots nearly 20 ton ha^-1. The plantation of PTPN VII in Cinta Manis District applied urea with a dosage of 5 kg ha^-1 but the result was not effective. There is a potential to try a higher dosage of urea to enhance trash decomposition. This research aims to evaluate urea application on biomass decomposition. This research was conducted on the Plot 07 Rayon 3 of PTPN VII, District of Cinta Manis at Ketiau, Lubuk Keliat of Ogan Ilir, South Sumatra, using Split Plot design. Main plot is trash sampling time and subplot is urea dosage with three replicates. ANCOVA was used for soil data. The rate of decomposition of the litter was calculated by the change in the initial condition of research with each week on observation resulting in decomposition rate graphs. Urea application at 10 kg ha^-1 reduced C/N of the litter ratio to almost 21:1 and was followed by the highest total nitrogen increase to 0.18%, while the highest organic carbon decline for urea treatment of 6 kg ha^-1 amounted to 13.78%. In conclusion, higher rate of urea application is still required to enhance sugarcane litter decomposition.</p>