Search Results (41)

(1) Background: Global grain production faces challenges such as increasing demands due to population growth, limited arable land resources, and climate change, with natural resource and environmental constraints becoming increasingly stringent. Traditional smallholder economies struggle to meet the increasing demand for grain, resulting in a tight balance between grain supply and demand. Therefore, to improve grain production efficiency (GPE), clarifying the specific effects of agricultural production services (APS), a new driving force on farmers’ GPE, is critical for ensuring grain security and achieving sustainable grain production. (2) Methods: Through the super-efficiency Data Envelopment Analysis (DEA) and Tobit models, and utilizing microdata from 747 farmers from the China Rural Revitalization Survey (CRRS), we analyzed the differences in farmers’ operating scales and types of agricultural production services to determine the extent and specific implementation effects of agricultural production services on the farmers’ GPE. (3) Results: agricultural production services enhanced the farmers’ GPE. Specifically, labor-intensive services (LIS) markedly improved the GPE of smallholder farmers but not large-scale farmers; technology-intensive services (TIS) did not have a substantial influence on either the smallholder farmers or large-scale farmers. There were significant regional differences in the threshold effect of agricultural production services on the GPE of the farmers. (4) Conclusions: Providers of agricultural production services should enhance their service capabilities to meet farmers’ diverse service needs. Government departments should establish uniform service standards and regulate industry development. Village and community organizations should leverage their grassroots coordination functions to facilitate the efficient operation of services. In addition, tailored development models should be developed for farmers of different scales, and they should be provided with financial and technical support as well as institutional guarantees. Full article

Hybrid electric vertical take-off and landing (HEVTOL) flying vehicles serve as effective platforms for efficient transportation, forming a cornerstone of the emerging low-altitude economy. However, the current lack of co-optimization methods for powertrain component sizing and energy controller design often leads to suboptimal HEVTOL performance. To address this, this paper proposes a hierarchical manifold-enhanced Bayesian evolutionary optimization (HM-BEO) approach for HEVTOL systems. This framework employs lightweight manifold dimensionality reduction to compress the decision space, enabling Bayesian optimization (BO) on low-dimensional manifolds for a global coarse search. Subsequently, the approximate Pareto solutions generated by BO are utilized as initial populations for a non-dominated sorting genetic algorithm III (NSGA-III), which performs fine-grained refinement in the original high-dimensional design space. The co-optimization aims to minimize fuel consumption, battery state-of-health (SOH) degradation, and manufacturing costs while satisfying dynamic and energy management constraints. Evaluated using representative HEVTOL duty cycles, the HM-BEO demonstrates significant improvements in optimization efficiency and solution quality compared to conventional methods. Specifically, it achieves a 5.3% improvement in fuel economy, a 7.4% mitigation in battery SOH degradation, and a 1.7% reduction in system manufacturing cost compared to standard NSGA-III-based optimization. Full article

The Yangtze River Basin, the largest river basin in China, faces complex challenges in population, economy and water issues. This study builds a Systemic Deduction Model of the Development of Yangtze River Basin (SDMY), which is based on system dynamics coupled with the water environmental model. It generalizes the Yangtze River Basin into five subsystems at the province level as well as two subsystems at the river basin level, quantifying the interaction and feedback relationships within and among each subsystem through functions. SDMY has passed the feasibility verification and the sensitivity analysis. The application results from 2000 to 2100 of SDMY show the positive development trend of gross domestic product (GDP), grain production, energy consumption, and forest coverage, as well as the significant risk of population decline. The water pollutants chemical oxygen demand (COD) and total phosphorus (TP), the water security level, and the river longitudinal connectivity of the Yangtze River Basin show reasonable and meaningful development trends, as the results indicate. This paper proves that SDMY could be a quantitative simulation tool for analyzing the long-term mutual feedback and evolution of the human–water relationship and society–economy–environment system in a large river basin. Full article

Income inequality impedes rural economic development. As the digital economy advances, e-commerce (EC) offers a novel solution to reduce rural income inequality. Based on the framework of the equality of opportunity theory, this research utilizes data from China Rural Revitalization Survey, using the RIF model and mediation effect model to investigate the influence and mechanisms of e-commerce operations (EOs) on the farmers’ income gap (FIG), while also analyzing the heterogeneity of EO’s effects on the FIG. Consequently, the impact of the varying scales and modes of EOs on the FIG is further examined. The findings indicate that EO can substantially diminish the FIG, as corroborated by robustness and endogeneity tests. The findings of the intermediate effect indicate that EO diminishes the FIG by reducing the disparity in labor endowment. The heterogeneity study results indicated that EOs are more effective in reducing the FIG in western China, major grain-producing areas, and mountainous areas. Further discussion reveals a stronger reduction effect of large-scale and platform EC. This study provides micro-level evidence that the digital economy empowers farmers for sustainable development and prosperity. The government should improve rural EC support and create a mechanism for disadvantaged rural populations. To reduce EC development discrepancies and promote farmer equity, specific assistance programs for undeveloped regions are needed. Local governments can also strengthen skill training programs for farmers, especially low-income ones, to boost labor skills. Finally, they can assist rural EC’s transformation to large scale and flat, maximize its role in employment, and narrow the FIG. Full article

Global challenges such as climate change, ecological imbalance, and resource scarcity are closely related with land-use change. Arid land, which is 41% of the global land area, has fragile ecology and limited water resources. To ensure food security, ecological resilience, and sustainable use of land resources, there is a need for multi-scenario analysis of land-use change in arid regions. To carry this out, multiple spatial analysis techniques and land change indicators were used to analyze spatial land-use change in a typical inland river basin in arid Northwest China—the Tailan River Basin (TRB). Then, the PLUS model was used to analyze, in a certain time period (1980–2060), land-use change in the same basin. The scenarios used included the Natural Increase Scenario (NIS), Food Security Scenario (FSS), Economic Development Scenario (EDS), Water Protection Scenario (WPS), Ecological Protection Scenario (EPS), and Balanced Eco-economy Scenario (BES). The results show that for the period of 1980–2020, land-use change in the TRB was mainly driven by changes in cultivated land, grassland, forest land, and built-up land. For this period, there was a substantial increase in cultivated land (865.56 km²) and a significant decrease in forest land (197.44 km²) and grassland (773.55 km²) in the study area. There was a notable spatial shift in land use in the period of 1990–2010. The overall accuracy (OA) of the PLUS model was more than 90%, with a Kappa value of 85% and a Figure of Merit (FOM) of 0.18. The most pronounced expansion in cultivated land area in the 2020–2060 period was for the FSS (661.49 km²). This led to an increase in grain production and agricultural productivity in the region. The most significant increase in built-up area was under the EDS (61.7 km²), contributing to economic development and population growth. While the conversion of grassland area into other forms of land use was the smallest under the BES (606.08 km²), built-up area increased by 55.82 km². This presented an ideal scenario under which ecological conservation was in balance with economic development. This was the most sustainable land management strategy with a harmonized balance across humans and the ecology in the TRB study area. This strategy may provide policymakers with a realistic land-use option with the potential to offer an acceptable policy solution to land use. Full article

Most river deltas worldwide are located in well-developed, densely populated lowland regions that face challenges from accelerated sea level rise. Deltas with morphological equilibrium are the foundation for associated prosperous economies and societies, as well as for preserving ecological fragile environments. And for deltas to be in morphological equilibrium, sufficient fluvial sediment supplies are fundamental. Severe droughts have significant impacts on the sediment load discharged to the sea, but this is considerably less studied compared to flooding events. This study examines the characteristics of Yangtze River sediment flowing toward the East China Sea during severe droughts. The effect of the Three Gorges Dam (TGD) was investigated by comparing the difference before and after its construction in 2003. Results indicate that the sediment load from the Yangtze River to the sea has experienced a more pronounced decrease during severe drought years since 2003. The primary cause is a substantial reduction in sediment supply from the upper reaches, resulting from the impoundment of the Three Gorges Reservoir created in 2003 and the construction of additional major reservoirs in the upper reach thereafter. Simultaneously, this is accompanied by the fining of sediment grain size. The fining of sediment and considerably reduced sediment load discharged to the sea during severe droughts after 2003 are likely to accelerate the erosion of the Yangtze subaqueous delta. The rating parameter values during severe drought years fall within the range observed in normal years, indicating that these drought events do not align with extreme rating parameter values. Less than 30% of the average discrepancy between measured and reconstructed sediment loads in severe drought years before 2003, and approximately 10% of the discrepancy after 2003, demonstrate the feasibility of reconstructing sediment loads for severe drought events using a sediment rating curve. This rating curve is based on daily water discharge and sediment concentration data collected during the corresponding period. These findings indicate that the rating curve-based reconstruction of sediment load performs well during severe droughts, with relative error slightly exceeding the average error of normal years prior to 2003 and approaching that observed after 2003. This study provides insights on sediment management of the Yangtze River system, including its coastal zone, and is valuable for many other large river systems worldwide. Full article

Singapore, being a land-scarce country, imports more than 90% of the food supply, which poses a challenge in ensuring food security. In the last five years, Singapore, with a population of 5.9 million, generated approximately 759 tonnes of food waste on average, thus further deepening food security challenges and imposing enormous pressure on the country’s food and land resources. The Zero Waste Plan and the 30-by-30 food security goal initiated by the Singapore government focus on reducing waste and improving resource efficiency and encourage the collective efforts from the local agri-food businesses to sustainably provide 30% of Singapore’s nutritional requirements by 2030. In recent years, valorizing food waste streams into higher-value products has been an increasing trend in tackling food wastage and offering a new source of food ingredients. Food wastes such as okara, spent barley grains, and fruit and vegetable wastes have been successfully valorized into a variety of prototypes by local research and development capabilities for food and agricultural applications. However, food waste valorization faces various challenges, i.e., infrastructure development, economy viability, consumer awareness, collaborative partnership, regulatory support, and data management. This review serves as a reference for other countries in ensuring food security and achieving sustainable development goals. Full article

Population growth exacerbates the pressure on land carrying capacity, affecting the sustainability of agricultural production, and also impacts non-agricultural industries. This paper utilizes grain price data from southern China during the Qing Dynasty (1776–1910) to examine the impact of population and land pressure on the development of the commodity economy under the “involution” of smallholder agriculture. This study finds that under conditions of stagnant technological advancement and limited natural resources, population growth during the Qing Dynasty created significant “Malthusian” population pressure. This pressure on land first resulted in the over-concentration of agricultural labor and saturation of the farming population. Surplus labor, unable to be absorbed by agriculture, shifted to non-agricultural sectors, engaging in the transportation and trade of grain. The pressure on land carrying capacity facilitated the cultivation and processing of cash crops, and product trade was supported by efficient waterway transportation. These activities generated commercial profits that alleviated survival pressures and promoted the prosperity of the commodity economy. However, this prosperity did not accompany significant productivity improvements; instead, it was a product of “involution” agriculture under high population density pressures. Full article

For the main grain-producing areas worldwide that balance multi-tasks of grain production, ecological protection, and economic development, quantitatively revealing the correlation between human activity intensity (HAI) and ecosystem service value (ESV) is conducive to formulating adapted ecological protection policies and promoting the coordinated development of the regional economy, society, and ecosystem. In this paper, we took the Songnen Plain of China as an example, employed a modified Equivalent Factor Method (integrating socio-economic data, the normalized difference vegetation index (NDVI), and land use data), and the HAI Assessment Model (based on the data of land use, night-time light, and population spatial distribution) to measure the ESV and HAI in the Songnen Plain of China for the years 1990, 1995, 2000, 2005, 2010, 2015, and 2020. We further applied the standard deviational ellipse method, the coupled coordination degree model, and the bivariate spatial autocorrelation models to reveal the spatiotemporal dynamics and correlation characteristics of ESV and HAI. The results showed the following: (1) Temporally, the ESV declined from 950.96 billion yuan in 1990 to 836.31 billion yuan in 2015, and then increased to 864.60 billion yuan in 2020, with the total loss attributed to the significant decline in the ESV of the natural ecosystem. Spatially, the ESV in the western and northeastern regions was relatively high, with a significant increase in the northeast. (2) HAI showed an upward trend from 1990 to 2020, while the high HAI levels gradually shrank after reaching the peak in 2000. Low HAI levels were mainly distributed in the northeast and southwest, aligning with the ecological space, while high HAI levels were distributed in the middle and southeast. (3) The interaction between ESV and HAI was marked by a negative correlation, transitioning from conflict to coordination. The spatial pattern of HAI and ESV showed H (HAI)-L (ESV) and L-H clustering, with H-H and L-L scattered distributions. This study contributes to providing a framework, methods, and suggestions for the sustainable planning and utilization of land and ecological protection in order to offer scientific references for the Songnen Plain, other major grain-producing areas, and related studies. Full article

Due to a continuously developing population, our consumption of one of the most widely used building materials, concrete, has increased. The production of concrete involves the use of cement whose production is one of the main sources of CO₂ emissions; therefore, a challenge for today’s society is to move towards a circular economy and develop building materials with a reduced environmental footprint. This study evaluates the possibility of using new sustainable supplementary cementitious materials (SCMs) from waste such as recycled concrete aggregates (RCAs) and mixed recycled aggregates (MRAs) from construction and demolition waste, as well as bottom ash from olive biomass (BBA-OL) and eucalyptus biomass ash (BBA-EU) derived from the production of electricity. A micronisation pre-treatment was carried out by mechanical methods to achieve a suitable fineness and increase the SCMs’ specific surface area. Subsequently, an advanced characterisation of the new SCMs was carried out, and the acquired properties of the new cements manufactured with 25% cement substitution in the new SCMs were analysed in terms of pozzolanicity, mechanical behaviour, expansion and setting time tests. The results obtained demonstrate the feasibility of using these materials, which present a composition with potentially reactive hydraulic or pozzolanic elements, as well as the physical properties (fineness and grain size) that are ideal for SCMs. This implies the development of new eco-cements with suitable properties for possible use in the construction industry while reducing CO₂ emissions and the industry’s carbon footprint. Full article

As a result of the depletion of fossil resources, ongoing population growth, and the industrialized economy, energy demand has been rising quickly throughout the world. India is now the world’s third-largest oil consumer, surpassing Japan and Russia. Today, biofuel research is conducted worldwide because surrounding two essential characteristics: sustainability and renewability. Biofuels have gained considerable significance as a result of dwindling oil sources, worries about energy security, and the escalating environmental issues associated with climate change and greenhouse gas emissions. In most cases, biofuels are produced by subjecting materials that have been densified to the process of heat conversion. In the disciplines of research and development, alternative energy development is a top focus. Due to the depletion of fossil fuel resources, it has become important to find innovative replacements for fossil fuels, such as biofuels, to generate heat and power. Biofuels may be generated using several methodologies, encompassing biological, chemical, and physical approaches. The three steps of densification systems’ pre-, during-, and post-pelletization procedures convert biomass into pellets. Several agricultural wastes, such as grain dust, crop leftovers, and fruit tree residues, are available as sources of agricultural energy. Bioenergy from biomass, such as leftovers and energy crops, can be used to produce contemporary energy carriers. This article focuses on an overview of sustainable and renewable biofuel resources and their commercialization. Full article

Agriculture is an important sector in Zimbabwe’s economy. More than 70% of the population are smallholders relying on agriculture. To support agriculture, Zimbabwe’s government introduced a Targeted Command Agriculture Programme (TCAP), in terms of which the state provides production inputs like seeds, fertilisers, protection chemicals, and extension services. In turn, the farmer is expected to produce 5 tonnes of maize per hectare for the Grain Marketing Board. The cost of inputs that the state provided is then deducted from the 5-tonne maize yield, and the farmer is paid the balance. Numerous authors have studied the design of TCAP and its impact on farmers. However, only a few have focused on the determinants of participation, especially with an empirical basis and in the Mutare District. To bridge this knowledge gap, this study implements a double-hurdle model to determine factors influencing farmers’ participation in Zimbabwe’s TCAP using a sample of 350 farmers. The study found that gender, family size, farmer type, command agriculture education, and distance from the market influenced smallholder farmers’ participation in TCAP. Therefore, policymakers should consider these factors to improve the design of the programme and enhance the participation of smallholder farmers in it. Full article

The Sanjiang Plain stands as a pivotal grain-producing region in China. Faced with population growth and the imperative of ensuring food security, the rapid expansion of agricultural land in the Sanjiang Plain has led to escalating ecological and water-environmental challenges, hindering the sustainable development of regional agriculture. This research aims to explore and propose practical measures for utilizing agricultural drainage resources to address the ecological and water-environmental issues resulting from agricultural expansion in the Sanjiang Plain, striving to achieve harmonious and sustainable economic and environmental growth. The discussion revolves around the potential alleviation of water quality, water quantity, and ecological health issues in the Sanjiang Plain through the proposed approach. Considering regional characteristics, the focus is on potential environmental drawbacks resulting from the improper application of the method. Building on these findings, effective strategies are presented to enhance the systematic operation of agricultural drainage resource utilization in the region. In conclusion, addressing ecological and water-environmental challenges stemming from local agricultural development is imperative for the Sanjiang Plain to realize sustainable development for the economy and the environment. Full article

With the endless growth of the population and development of the economy and living standards, a high yield with good grain quality has become the prime objective of breeding. However, lodging is a major factor leading to a significant decline in rice (Oryza sativa L.) production and quality. We conducted genome-wide association analysis to detect quantitative trait loci (QTL)-related lodging resistance, using 395 temperate geng accessions. A total of 50 QTL affecting the six traits were detected, using 1,438,279 high-quality single nucleotide polymorphism markers. Five important QTL clusters were detected affecting the lodging resistance-related traits. The ten candidate genes were detected by performing gene differential expression analysis and haplotype analysis. Among them, LOC_Os07g48570 (OsDof-23) for qLA7.2, qSA7.2 and qPR7.3, LOC_Os08g29110 (wp2) for qLA8 and qSA8, and LOC_Os11g36440 (MHZ5) for qPR11 and qBR11.1 were considered the most likely candidate genes based on functional annotations. The results may facilitate the breeding of rice varieties resistant to lodging, to overcome the adverse effects of climate change. Full article

The total factor productivity of grain (TFPG) is critically important to secure food production, while its spatiotemporal heterogeneity in the urbanized area is largely ignored. Selecting 41 cities in the Yangtze River Delta, this study uses the data envelopment analysis (DEA) Malmquist index method to measure the TFPG in each city from 2012 to 2020 based on panel data, and explores the driving factors of the spatiotemporal evolution of the TFPG with the geographically and temporally weighted regression model. The results indicate the following: (1) Both the TFPG and technological progress varies in the same direction, indicating that technological progress dominates the TFPG in the studied region. The changes in technical efficiency, pure technical efficiency, and scale efficiency are relatively stable. (2) The spatial distribution of the TFPG shows a decentralized trend, with a pattern of high in the north and east areas and low in the south and west areas. (3) The driving factors, such as the development level of the grain economy, the amount of fertilizer used per unit area, and gross domestic product (GDP) per capita, have a restraining effect on the improvement of the TFPG, in which the amount of fertilizer used per unit area is the critical factor. (4) The scale of per capita labor operation, the proportion of the grain-growing population, and output of grain per hectare exert a promoting effect on the TFPG, in which both the proportion of the grain-growing population and output of grain per hectare are the critical factors. Finally, improving the efficiency of fertilizer use, expanding the production scale of the grain planting industry, and increasing the output of grain per hectare are proposed to improve the TFGP in the Yangtze River Delta. Full article