Effects of Sewage Sludge on Tree Growth, Soil Properties and Groundwater Quality

Effect of sewage sludge on the growth of plants is well documented for many agricultural and horticultural crops but limited research has been conducted on forest trees. The organic matter in sewage sludge can improve the soil physical and chemical properties but it also contains varying amounts of heavy metals that may cause toxicity and potentially can contaminate the groundwater. Thesis reports two studies on the effects of sewage sludge on tree growth, foliar nutrients, soil properties and groundwater quality. The first study was conducted in the greenhouse with using two timber species viz Dyera costulata and Cinnamomum iners. Factorial experiments of 10 x 2 x 4 were conducted to study the effect of sewage sludge on the growth performance and foliar nutrient concentrations at the 10 levels of treatment. After six months of treatment, the results showed that T7 (70% of sludge by volume) and T6 (60% of sludge by volume) gave the highest height and growth diameter for D. costulata and C. iners, respectively. The use of sewage sludge at the rate of more than 70% for D. costulata and 60% for C. iners did not gave the significant different in terms of height, diameter and foliar nutrient concentrations. The study also indicates that the critical nutrient levels for D. costulata and C. iners were correspond to treatments 6 and 7, respectively. The second study was a field experiment with comprising of five tree species viz S. leprosula, D. costulata, A. mangium, C. iners and H. odorata using t-test comparing two main treatments; plots treated with sewage sludge at the rate of 4050 m3/ha and a control (untreated). The results showed that all the species treated with sewage sludge were significantly higher in terms of height and growth diameter compared than the corresponding species in the control plot. The concentrations of foliar nutrients in the five species were significantly higher (P10.05) in the treated than the corresponding trees in the control plots. This implies that sewage sludge significantly affected the concentration of foliar nutrients uptake. The fertility of the soil for both macronutrient (N, PI K, Ca, Mg and Na) and micronutrients (Mn, Zn, Fe and Cu) in the treated plot were also higher than the control plots. However, the concentration of micronutrients and other heavy metals in the foliar and soil did not exceed the maximum permitted concentrations (MPC) of the European Community Standard (ECS). Water quality monitoring showed that the groundwater within the experimental area was contaminated with organic contaminants and nutrient compounds. The concentrations of arsenic, manganese, ammoniacal-nitrogen, phenol, BODS and COD exceeded the limits recommended by the national guidelines for drinking water quality. The presence of E. coli in the groundwater samples indicated that the samples had been contaminated with this organism. Generally, this study indicates that sewage sludge significantly affects tree growth, foliar nutrient concentrations, soil properties and groundwater quality. Disposal of sewage sludge therefore has to be thoroughly monitored to avoid soil and groundwater contaminations

Financial viability of small farm forestry based on no-cost sharing arrangement in Sal (Shorea robusta) forest of Bangladesh

The Sal (Shorea robusta) forests provide a substantial part of the forest cover of the country and contribute to the economy by providing timber, firewood, fodder, non wood forest products and by protecting the environment. Due to over exploitation the forest is being degraded. The Forest Department of Bangladesh had initiated a program through the participation of the present encroachers to stop this overexploitation. The centerpiece of this attempt was a no-cost sharing arrangement. A number of 63 settlers who were landless and encroachers before joining the program were settled in the forest. The settlers were provided 1.21 ha/299.51 acres degraded forestland with full input support. The current study examined the financial viability of the farms, including homesteads, based on this arrangement. The BCA approach was employed to determine the net incremental benefit. It was found that a no-cost sharing arrangement option was financially feasible. Sensitivity analysis showed that the NPV is sensitive to the cost items of the program. The NPV, IRR and BCR, BIR and AI of the program showed the feasibility of the program. The discount rate used in the analysis was the real discount rate (5.67%). The sensitivity of NPV to the discount rate was also examined and found the program was more feasible at a 10% nominal discount rate. The sensitivity analysis also showed that a decrease or an increase in cost and benefit respectively could substantially change feasibility indicators. The no-cost sharing arrangement could be replicated to manage forest resources at the initial level to create a multiplier effect for sustainable use of resources. Integration of technologies such as bee keeping or Seri-culture to the program could increase the scope of labor utilization and output of the degraded land.small-scale forestry, Sal forest, Dhaka, no-cost sharing arrangement

Assessment of heavy metal uptake and translocation in Acacia mangium for phytoremediation of cadmium-contaminated soil.

Soil and water pollution have become a major environmental problem, attracting considerable public attention over the last few decades. Many organic and inorganic pollutants, including heavy metals, are being transported and mixed with the cultivated soils and water. Heavy metals are dangerous environmental pollutants that can be transferred and accumulated in human and animal bodies causing DNA damage and carcinogenic effects. These soil contaminants need to be cleaned up for safety environment. Experiment was conducted to evaluate the potential of Acacia mangium as a phytoremediator to absorb heavy metals from contaminated soils. A. mangium seedlings were planted on six different growth media (soil + different levels of cadmium) were: T0 (Control, soil), T1 (25 ppm Cd), T2 (50 ppm Cd), T3 (75 ppm Cd), T4 (100 ppm Cd) and T5 (150 ppm Cd). The highest growth performance such as basal diameter, height and number of leaves was found in T3, T2 and T4 treatments, respectively. The highest accumulation of Cd (28.29 ppm) was recorded in T5, Cu in T2 (23.69 ppm) and Zn (241.96 ppm) in T4. Cu was highly concentrated in the roots, Cd was accumulated in the stems, whereas Zn was both in stems and leaves. A. mangium showed high translocation factor (TF) and low bioconcentration factor (BCF) values in soil at higher metal concentrations as well as it was able to tolerate and accumulate high concentrations of Cd, Cu and Zn. The roots of A. mangium were found to be suitable for the absorption of heavy metals in contaminated soils, especially Cu. Cd was accumulated in the stems while Zn in both stems and leaves. This species can be a good efficient phytoremediator for soils contaminated with Cd, Cu and Zn to mitigate soil pollution

Upm terima ayam awet onagadori berekor terpanjang di dunia dari kerajaan Jepun

SERDANG, 19 Sept - Universiti Putra Malaysia (UPM) menerima Onagadori, iaitu ayam berekor terpanjang di dunia dari kerajaan Jepun , sebagai simbol untuk memperingati perkongsian strategik dengan Persekutuan Ekonomi Kyushu (Kyukeiren)

Assessment of heavy metal uptake and translocation by Pluchea indica L. from sawdust sludge contaminated soil.

Chemical pollution in the soil and water bodies has become a major source of concern and has posed a serious health problem in many countries. An experiment was conducted in sawdust contaminated soils at glasshouse to determine the growth response, metal tolerance and phytoremediation potential of Pluchea indica. P. indica seedlings were planted in the following growth media: T 0 (Control, 100% soil), T 1 (80% soil + 20% sawdust sludge), T 2 (60% soil + 40% sawdust sludge), T 3 (40% soil + 60% sawdust sludge), T 4 (20% soil + 80% sawdust sludge) and T 5 (100 % sawdust sludge). The best growth performance in terms of height, basal diameter and number of leaves was found in 40% sawdust in combination with 60% soil. This combination also produced highest biomass. The maximum reduction of copper and zinc was found in 80% sawdust contaminated media, iron and aluminium in the control while lead was in T5 (100% sawdust). Cu, Fe and Al were highly concentrated in the roots, Pb both in stems and roots while Zn was concentrated both in roots and leaves. P. indica was found to have a high potential to accumulate high amounts of Cu, Fe, Al, Pb and Zn in the roots, leaves and stems. Control to medium contaminated soil showed maximum translocation factor. The species was able to tolerate and accumulate high concentrations of heavy metals. Being a non-food plant P. indica can be an ideal option to be grown for phytoremediation in multi-metal contaminated sites. A field experiment also needs to be conducted to confirm the results of this glasshouse study

Nutrient status of frond heaps and the underlying soils at an 18-year-old oil palm field in Central Pahang, Malaysia

In oil palm plantation, palm fronds are pruned off upon fruit bunch harvest and heaped up in-between palm trees, which is called as a frond heap. This study examined the amounts of nutrients contained in frond heaps and their influence on the underlying soil fertility at an 18-year-old oil palm field in Central Pahang, Malaysia. Based on biomass measurement and nutrient analysis, the amounts of C, N, P, K, Ca, and Mg in the frond heaps were estimated to be 697, 11.8, 0.810, 18.9, 8.05, and 2.73 g m-2, respectively. Meanwhile, the surface soils below the frond heaps showed higher levels of pH, EC, total C, N, exchangeable Ca, Mg, and K than those at harvest path, which is operation path for workers to harvest, while available P was more accumulated at weeded circle, to which fertilizer is applied under the palm canopy. These tendencies were more obvious compared with our previous study conducted at a 10-year-old field located in the same region. This study reveals that the nutrients released from decomposing frond heaps could contribute to build-up of the major nutrients except for P in the underlying soils to be recycled by palm trees