Fertilizer Deep Placement Significantly Affected Yield, Rice Quality, 2-AP Biosynthesis and Physiological Characteristics of the Fragrant Rice Cultivars

The management of fertilizers in a context of climate change and the preservation of the environment is strongly related to the regulation and accumulation of 2-acetyl-1-pyrroline (2AP) in fragrant rice. However, the feasibility of such management strategies in terms of enhancing the accumulation of 2AP has not yet been explored in aromatic cultivars. Here, we investigated the impact of the application of two fertilizers at three depth (surface, 5 cm and 10 cm) levels of placements to improve the aromatic rice quality, including such aspects as the 2AP content-, protein-, amylose- and yield-related traits. For this purpose, two known rice cultivars, Basmati 385 (B-385) and Yunjingyou (YJY), were grown in pots during 2019 and 2020 under fluctuating climates. The deep application of fertilizer at 10 cm significantly affected the 2AP content with such values as 127.53 μg kg−1 and 111.91 μg kg−1 obtained for Fragrant Fertilizer (FF) and Urea in B-385 cultivar, and 126.5 μg kg−1 and 114.24 μg kg−1 being observed for FF and Urea in YJY, respectively, during 2019. In addition, values of 108.41 μg kg−1 and 117.35 μg kg−1 were recorded for FF and Urea in B-385, while 125.91-μg kg−1 and 90.71-μg kg−1 were measured for FF and Urea in YJY, respectively, during 2020. Similarly, B-385 had better 2AP content and yield-related traits, as well as amylose content and cooked rice elongation, as compared to the YJY rice cultivar. The 2AP accumulation and its related biochemical parameters, and their relationships in different plant tissues at different growth stages under FF and Urea treatments, were also improved. Further, the 2AP content and the P5C activity demonstrated strong correlations during the grain filling periods in both fragrant rice cultivars. In conclusion, our findings have the potential to provide useful information to farmers and agriculture extension workers in terms of the saving of fertilizers and the improvement of rice grain quality under fluctuating climate conditions.

Water-Saving Irrigation and Nitrogen Fertilizer Use Efficiency for Irrigated Rice in the Red River Delta, Vietnam

The objective of this research was to quantify the effects of water-saving regimes and fertilizer application improvement on water productivity, N-use efficiency, and rice yield. The results showed that the tested water treatments did not have significant effects on the growth and development, yield components, and final grain yield, but water productivity was significantly increased from 1.28 kg grain m-3 (W0) water to 1.74 kg grain m-3 water (W1) and 1.94 kg grain m-3 water (W2). In addition, the percentage of total irrigation water saved from W1 and W2 were 25.24-44.52% compared to continuous flooding. Fertilizer deep placement (FDP) combined with organic compost significantly increased the grain yield of the tested hybrid rice variety. Average grain yield increased quickly from 2847 kg ha-1 with 0 kg N ha-1 to 5263 kg ha-1 with 120 kg N ha-1 under the fertilizer deep placement method. The highest total nitrogen uptake, agronomic nitrogen efficiency (ANE), and nitrogen uptake efficiency (NUE) were obtained from alternate wetting and drying at a -20cm water depth and the fertilizer deep placement method (W1N2). In addition, it also gave the highest income in comparison with the other treatments. Therefore, alternate wetting and drying at a -20cm water depth and fertilizer deep placement method should be encouraged for implementation in other regions of Vietnam.

Coastal and Marine Pollution in Bangladesh: Pathways, Hotspots and Adaptation Strategies

Marine and coastal pollution is a global issue for human health and biodiversity. We have investigated pollution sources, flow patterns, hotspots, challenges, and adaptation policies in Bangladesh. Industries, ship breaking yards, sewage, tourism, and transboundary depositions are the main sources of pollutions. The Ganges, Padma, Jamuna, Brahmaputra and Meghna carry wastes to the Bay of Bengal. Pollution hotspots are Dhaka, Gazipur, Narshingdi, Narayanganj, Chittagong, Khulna, Mongla port and Sylhet city. Textile and dyeing industries discharge 12.7–13.5 million m3 waste waters annually and pollute 20% of fresh water. Ship breaking yards dump about 22.5 tons polychlorinated biphenyls in a year. More than 50% of the marine oil pollution comes from urban activities. Plastic wastes at 3000 t day-1 and tourism are also contributing to the coastal pollution. Effluent releasing standards are not maintained, and thus higher concentrations of heavy metals are found with marine fishes. Use of heavy metal tolerant crops (rice: BRRI dhan47, potato: Cardinal, mustard: Brassica napus, flower: Marigold, vegetables: Cucumber, fibre: Kenaf, and so on), trap cropping, deep placement of fertilizers, integrated rice-fish-duck culture, etc can be adopted in polluted areas. There are laws for environmental issues, but coordination and financial capabilities does not warrant its effectiveness. Necessary steps are to be taken to improve infrastructure to ensure sanitation and benign discharge of industrial effluents. Systematic study on sources, fate and extent of current effluents dumping in water ways need to be assessed for wellbeing of aquatic life and human health.