The critical limit for zinc (Zn) varies from 0.38 to 2 µg/g soil depending on the crop and soil type. However, the critical limit for Zn was not explored recently for rice and potato cultivation in the floodplain soils of Bangladesh. A pot experiment was conducted to determine the critical limits of Zn in soil and plants for rice and potato cultivation in two agro-ecological zones (AEZs) of Bangladesh. The soil samples were collected from 20 different locations of Old Brahmaputra and Active Ganges Floodplains with low (1.80 µg/g) Zn status. The experiment was laid out in a factorial and completely randomized design with two levels of Zn (Zn₀ and Zn₁ (0 and 4.87 kg/ha as Zn sulphate)) applied to 20 different soil samples for rice and potato cultivation using three replications. The critical limit of Zn was determined through a graphical and statistical approach and crops were harvested at the stem elongation (for rice) and tuber filling (for potato) stage. The critical limit of Zn in soil for rice was found to be 0.8 and 0.85 µg/g by graphical and statistical methods, respectively, and both methods revealed the same value (0.73 µg/g) for potato. The critical limit of Zn in rice plants was 23.9 and 24.32 µg/g, whereas in potato plants it was 27.1 and 26.61 µg/g, determined by graphical and statistical methods, respectively. The added Zn supply in soil significantly increased the dry matter accumulation in rice (by 5.6%) and potato (by 10%) compared to no Zn supply. Therefore, a significant positive response to added Zn could be observed on crop growth and yield when the Zn concentration remained below the mentioned critical level for rice and potato cultivation in floodplain soils of Bangladesh.

This study intends to explore the extent of the use of information and communication technology (ICT) in flash-flood-prone haor (wetland ecosystem) areas of north-eastern Bangladesh. Addressing the situation of severe flash floods in 2017 at the community level, this study aims to examine the constraints and challenges in using ICT for flash flood risk management. An empirical study was conducted in two upazilas (administrative sub-districts) within the Sunamganj, the most affected district. A total of 120 household heads were interviewed using a semi-structured questionnaire. Focused group discussions (FGD) and key informant interviews (KII) were also used. Results reveal that people in these areas do not use computers or Internet. However, the use of mobile phones is common for communication during disasters. Illiteracy, poor quality of life, poor social capital, poor infrastructure, and poor communication with institutions are highlighted as the main constraints and challenges in the effective application of ICT in flash flood management. The results showed that the local community people of the study area receive early warning and hazards preparedness-related information through mobile phones, television, radio, and Facebook. However, the results also highlighted the constraints and challenges in applying ICT in DRR at the community level. By addressing a remote region and a relatively less focused disaster (flash flood), this study contributes to boosting the application of ICT in DRR, especially in remote, disadvantaged communities.

Crop production is unexpectedly hampered by different abiotic stresses. Salinity is one of the leading stresses, which snappishly hampers plant developmental progression. Local rice landraces exhibit noticeable salt tolerance as well as high yield. However, research is scarce about the physio-biochemical responses of local landraces and modern cultivar under saline conditions. Therefore, the present experiment was designed to reveal the physio-biochemical responses of local landraces and modern cultivar under salinity stress. Five landraces (Jotai, Icheburogolghor, Morishal, Chapail, Kumro buro) and two modern cultivars (BR23 and BRRI dhan41) were subjected to 0, 20, 40, 60 and 80 mM NaCl treatment. The effects of salt stress on morphological parameters, proline contents, and activities of antioxidant enzymes were assessed. Salt stress reduces the morphological parameters of all tested cultivars. The Morishal and BRRI dhan41 exhibited higher growth of plant and physiological parameters than other cultivars under the highest salinity. The catalase (CAT) and ascorbate peroxidase (APX), exhibited a significant increase whereas peroxidase (POX) activity significantly declined in all the cultivars under salinity stress. Morishal and BRRI dhan41 showed the highest proline content under the maximum saline condition. These results suggest that the high tolerant landrace and modern cultivars were Morishal and BRRI dhan41 respectively. These results also suggest that Morishal and BRRI dhan41 exhibited high tolerance to salinity by enhancing proline content and antioxidant enzyme activities.