Volume 3 Issue 4
Authors: Md. Reaz Uddin Khan; Abul Fazal M. Saleh
Abstract: Methane, a leading heat-trapping greenhouse gas (GHG), is produced primarily as a byproduct of intensive water use in rice cultivation. Though Bangladesh is the fourth-largest rice producing country in the world, its methane emission status has yet to be determined in order to consider future mitigation measures. Hence, this study employed CH4MOD2.5, the most widely-validated computer simulated semi-empirical model and the Intergovernmental Panel on Climate Change (IPCC) proposed simulation model were used in this study for estimation of methane emissions. Three focus group discussions (FGDs) were conducted with farmers of the Gazipur District to collect information for model inputs. Using IPCC methods, the average methane emission of Bangladesh was estimated to reach 1071 Gg yr-1. The rate estimated by the CH4MOD2.5 model was 464 Gg yr-1. Cultivar-specific average emissions for BR 11, BRRI dhan 28 and BRRI dhan 29 were 20.4×10-2, 69.9×10-2 and 96.7×10-2 kg CH4 ha-1 day-1, respectively. The projected emission values for all types of rice cultivation in Bangladesh conducted by United States Environmental Protection Agency (US-EPA) were 850 and 918 Gg in 2005 and 2010, respectively. Conversely, according to the IPCC methodology and the CH4MOD2.5 model, those figures were respectively estimated at 1087 and 1146 Gg in 2005, and at 471 and 496 Gg in 2011. Among the three methods, emission estimation was highest according to the IPCC methodology and lowest according to the CH4MOD2.5 model (45% lower than the US-EPA value). The variation is primarily due to the consideration of field level data as CH4MOD2.5 model inputs. In the business as usual scenario, Bangladesh’s predicted methane emission is approximately 653 and 906 Gg for 2030 and 2050, respectively.
Keywords: Methane Emission; CH4MOD2.5 Model; IPCC Model; Climate Change
Authors: Elham Ghodraty; Faezeh Zaefarian; Mohammad Rezvani; Iran Dokht Mansouri
Abstract: The ground cherry (Physalis alkekengi L.) is an annual summer dicotyledonous plant from the Solanaceae family. An important plant technique in order to continuously germinate in crop fields is seed dormancy. Therefore, the interruption of seed dormancy would help manage ground cherry crops. This study examined the effects of pre-chilling (wet and dry) at a temperature of 4 °C for 5, 15, 25 and 35 days, as well as the effects of a boiling water treatment (100 °C) did not germinate. Control and chilling for 15 days demonstrated the maximum germination percentage. Minimum germination occurred after pre-chilling for 25 and 35 days.
Keywords: Weed; Germination; Thermo-priming