Purpose: Evaluating the economic effects of climate change is a pivotal step for planning adaptation in developing countries. For Bangladesh, global warming has put it among the most vulnerable countries in the world to climate change, with increasing temperatures and sea-level rise. Hence, the purpose of this paper is to examine how climate change impacts the economy in Bangladesh in the case of climate scenarios. Design/methodology/approach: Using a dynamic computable general equilibrium (CGE) model and three climate change scenarios, this paper assesses the economy-wide implications of climate change on Bangladesh’s economy and agriculture. It is clear from the examination of the CGE model that the impacts of climate change on agricultural sectors were felt more sharply, reducing output by −3.25% and −3.70%, respectively, and increasing imports by 1.22% and 1.53% in 2030 and 2050, compared to the baseline. Findings: The findings reveal that, relative to baseline, agricultural output will decline by a range of −3.1% to −3.6% under the high climate scenario (higher temperatures and lower yields). A decrease in agricultural output results in declines in agricultural labor and household income. Household income falls in all categories, although it drops the most in urban less educated households with a range of −3.1% to −3.4%. On the other hand, consumption of commodities will fall by −0.11% to −0.13%, according to the findings. Although climate change impacts had a relatively small effect on gross domestic product, reducing it by −0.059% and −0.098% in 2030 and 2050, respectively. Practical implications: As agricultural output, household consumption and income decline, it will impact the majority of the population’s health in Bangladesh by increasing malnutrition, hidden hunger, poverty, changing food environment, changing physical and mental health status and a changing health-care environment. Therefore, population health and food security will be a top socioeconomic and political concern for Bangladesh Government. Originality/value: The examination of the dynamic CGE model is its originality. In conclusion, the evidence generated here can provide important information to policymakers and guide government policies that contribute to national development and the achievement of food security targets. It is also necessary to put more emphasis on climate change issues and address potential risks in the following years.

Responses of photosynthetic characteristics and enzyme activity of nitrogen metabolism to low nitrogen in maize with different nitrogen tolerance

Soil physical properties, nutrients, and crop yield with two-year tillage rotations under a winter wheat-summer maize double cropping system

Controlled-release urea (CRU-N) fertilizer application is a solution to improve the utilization rate of nitrogen (N), reduce economic costs and improve crop yields. It is significant to study the effects of release CRU-N reduction and the combined application of conventional urea on soil N control and the large-scale maize planting system. In this study, the effects of controlled-release nitrogen fertilizer reduction and postponement on soil nitrogen components, enzyme activities, and yields were investigated. Seven treatments were set up in this study, including no N fertilizer (CK), 100% conventional urea (U), 100% controlled-release urea (S), 30% controlled-release urea (SU3/7), 50% controlled-release urea (SU5/5), 70% controlled-release urea (SU7/3) and Sodium Salt of Polyaspartic Acid (PASP)-N. The results showed that mixed CRU-N and urea increased yields and net benefits compared with conventional urea at the same application rate of N, and reduced N loss. The application of CRU-N at 70% for maize represented the best overall effects. Compared with U treatment, soil ammonium nitrogen (NH4-N), soil nitrate-nitrogen (NO3-N), and microbial biomass nitrogen (SMB-N) of CRU-N at 70% (SU7/3) increased by 35.00%, 15.53%, and 25.04%. However, soil nitrate reductase (S-NR) and urease (S-UA) were the best in SU5/5 and significantly higher than other treatments. The applications of CRU-N would effectively increase soil N; CRU-N in 50% proportion can promote the maize root growth and improve the efficient utilization of N by soil microorganisms. Like the yields (9186.61 kg/hm2), expertly in the proportion of 70% CRU-N (SU7/3) plays a vital role in a wheat-maize rotation system, which can potentially be used to improve the yields, nitrogen use efficiency, and net benefit with low N losses. In conclusion, using CRU-N fertilize effectively improves soil nitrogen, and various ratios of CRU-N can ensure the continuous release the nutrients during the growing period. And among the different proportions of CRU-N, it is optimal in SU7/3. Keywords: controlled-release urea, nitrogen regulation, maize grain yield, soil, reducing, postponing DOI: 10.25165/j.ijabe.20221501.6888 Citation: Ji P T, Peng Y J, Cui Y W, Li X L, Tao P J, Zhang Y C. Effects of reducing and postponing controlled-release urea application on soil nitrogen regulation and maize grain yield. Int J Agric & Biol Eng, 2022; 15(1): 116–123.

Growing green manure, as a sustainable agricultural practice, is widely recognized for its role in improving soil structure and enhancing soil quality. However, despite the significant benefits of green manure, research on how its application specifically influences soil organic carbon content remains insufficient, especially in the context of complex and ever-changing agricultural management models and ecological environments. In this study, 59 papers published from January 1980 to May 2024 were collected, and a database containing 299 groups of comprehensive effects of green manure planting on soil organic carbon content and crop yield, as well as its key regulatory factors, through a meta-analysis system. The research is mainly conducted through several key elements types of green manure, planting seasons, fallow periods of food crops, soil types, climate types, and planting years. The results show that compared with not growing green manure on fallow land, the cultivation of green manure significantly increased the soil organic carbon content (by 6.98%) and the yield of the next staple food crop (by 10.36%). In different planting seasons, both summer and winter planting of green manure can effectively increase the soil organic carbon (SOC) content and crop yield. Among them, the application effect during the fallow period of wheat and rice is particularly significant, while during the fallow period of maize, only the SOC content increases significantly. From the perspective of green manure types, both the single species of leguminous and the mixed species with cruciferous have shown good effects. The research also found that under soil types such as loam and clay loam, as well as climatic conditions like temperate continental climate, temperate monsoon climate, and subtropical monsoon climate, the effect of green manure planting on the increase of SOC and yield is more significant. In addition, the planting years are also an important influencing factor. Green manure planting for ≤3 a or >5 a can significantly improve the SOC content and crop yield. These findings provide important theoretical support for the scientific application and promotion of green manure in China.