Is japan's per capita CO2 emission serious?5 answersJapan's per capita CO2 emission is a significant concern due to its high levels compared to other regions. The country ranks fourth globally in CO2 emissions, with per capita emissions far exceeding the Asian average and being twelve times higher than in India. Despite efforts to stabilize CO2 concentrations and reduce emissions by 60%, challenges persist, especially in urban areas where environmental standards for pollutants like NOx and particulate matter are often not met. Additionally, studies analyzing CO2 emissions in Japan over time have shown a lack of evidence for environmental convergence, indicating a persistent issue with emissions. These findings underscore the seriousness of Japan's per capita CO2 emissions and the need for continued efforts to mitigate environmental impact.
How much methane is emitted in paddy rice fields per hectare per cycle?4 answersOn average, methane emissions in paddy rice fields per hectare per cycle vary based on factors like water management and agricultural practices. Studies show that methane emissions can range from 220 kg/hm2 for late rice to 470 kg/hm2 for single-season rice. Additionally, specific scenarios like optimized water management measures and the return of Chinese Milk Vetch can lead to reductions in methane emissions by 29-45% and 7.19-18.96%, respectively. Implementing strategies such as intermittent wetting and drying, along with the combined application of compost and NPK fertilizers, can further help reduce methane emissions by up to 40-45%. Overall, these findings highlight the importance of sustainable agricultural practices in mitigating methane emissions from paddy rice fields per hectare per cycle.
Why does methane emission has a positive correlation to plant height of rice paddy?5 answersMethane emission in rice paddy fields has a positive correlation with plant height. Varieties with larger and deeper root distributions and lower leaf dry weight can decrease methane emissions and maintain higher grain yield. Methane emissions are influenced by root morphological traits, such as root dry weight, root area index, and root volume density. Additionally, methane emissions exhibit significant positive correlations with leaf methane transport efficiency and leaf dry weight. Proper water management during the vegetative phase, which avoids water stress for plants, is effective in mitigating methane release. Soil temperature also plays a role in methane emission, with a positive correlation observed in both short-term and long-term trends. However, other factors such as water management and plant age can decrease this correlation in the long term.
However, rice farming can have negative environmental impacts, such as methane emissions and water use5 answersRice farming can have negative environmental impacts, such as methane emissions and water use. The rapid increase in atmospheric methane concentration is of significant environmental consequence, and rice fields are considered an important source of methane emissions. Rice cultivation in flooded areas generates greenhouse gases, including methane, carbon dioxide, and nitrogen oxides, contributing to global warming. Intensified farming practices and management systems have had negative impacts on farmland biodiversity, with chemical pesticides and modern irrigation/drainage systems posing threats to various taxa. Conventional rice farming systems with high inputs of agrochemicals can damage soil, decrease productivity, and increase methane emissions. Misuse of pesticides in rice fields has resulted in significant off-field environmental impacts, including accumulation in the food chain and detrimental effects on farmers' health. These findings highlight the need for environmentally friendly farming practices, reduced pesticide use, and the promotion of organic fertilizers to mitigate the negative environmental impacts of rice farming.
What are the high methane emission stage of rice plant?5 answersThe high methane emission stage of rice plants varies depending on the study. According to Wang et al., the highest CH4 emission was observed at the tillering stage. On the other hand, Zheng et al. found that seasonal total CH4 emission was negatively correlated with radial oxygen loss (ROL) in both the early and late rice seasons. Islam et al. observed that methane emissions peaked at the maximum tillering to flowering stages. Kaharuddin et al. found that continuous flooding resulted in higher methane gas emissions compared to intermittent flooding at 57 and 73 days after planting. Therefore, the specific stage of high methane emission in rice plants may vary depending on factors such as the tillering stage, ROL, and flooding conditions.
Which greenhouse gas is produced by paddy crop?11 answers