Suchergebnisse

China's economy has made great strides since 1949, and especially since China initiated economic reforms and the open-door policy in the 1980's. The growth in agricultural production has been one of the main national accomplishments. By 1999 China was feeding 22 % of the global human population with only 9 % of the world's arable land and per capita food availability reached the levels of developed countries. The use of fertilizers has played a crucial role, accounting for about 50 % of the yield increase. However, rapid economic growth has led to unprecedented resource exhaustion and environmental degradation. China's 'grain security' will face multiple pressures stemming from resource limitation, environmental pollution and population growth. The Chinese government regards agriculture as the primary field of development of the national economy in the 21st century. The optimal agricultural developmental path for China is to improve the ratio of resource utilization and to protect the environment while guaranteeing the grain supply. This paper summarizes the trends in crop production and crop yields, fertilizer use and soil quality in China, and presents the approach of integrated nutrient management (INM) for improving crop productivity with efficient resource utilization and environmental protection. In the INM approach, the strategy is to emphasize the integrated use of nutrients from fertilizers, wastes and soil and environmental sources; managing nutrients according to different nutrients' specific characteristics; and integrated nutrient management with sound soil management practices and other farming techniques. These new nutrient management systems can, on average, reduce N fertilizer inputs by 26%, save P fertilizer inputs by 20%, raise grain yields by 8%, and reduce N loss by 47 % compared to conventional agricultural practice.

Ensuring national food security amidst ongoing economic development whilst both protecting the environment and reducing the dependence on fossil fuels are significant challenges for Chinese sustainable development. The main objectives of this study were to reveal irrigated crop (wheat, maize, and sunflower) performance in terms of energy, economic, and environmental aspects in China's largest designed irrigation area, Hetao irrigation district (HID), and to evaluate agricultural suitability based on plant structure. An integrated indicator and comprehensively assessment method were used to evaluate the above objectives based on the results from in-person surveys. The results show that maize exhibits the best overall performance compared to two other major crops (wheat and sunflower), which supports the government policy of adjust and optimize the planting structure program (AOPST), an effective way to achieve the multiple-objectives for sustainable agricultural development. However, reducing fertilizer remains a more critical factor than AOPST. These study results provide useful guidance for policy-makers and relevant stake-holders both in a regional context for the HID and at the global agricultural governance and management level.

The Yangtze River Basin (YRB) has been recognized as one of the key strategic development regions in China. Agriculture p52 roduction systems in the YRB have contributed considerably to China's goal of food security. Realizing Agriculture Green Development (AGD) means agriculture production systems with high productivity, high resource use efficiency and low environmental costs. However, challenges and barriers still exist for realizing AGD in the YRB. Here, we summarize four main challenges for AGD in the YRB, and identify two approaches (top-down and bottom-up) including main strategies needed to achieve AGD. The four challenges include, but are not limited to, (1) low agricultural productivity and nutrient use efficiencies, (2) an uneven agricultural production structure, (3) rapid urbanization, and (4) uncoordinated targets for environmental protection and food production. We conclude that both top-down and bottom-up approaches are needed to deliver AGD in the YRB. Top-down approaches are mainly operated by government and underpinned by research, which uses spatial planning to promote the balance between agricultural production and the ecological environment, and to optimize the proportions of cereal and cash crop production with monogastric and ruminant animal production. The bottom-up approach needs strategies to close the yield gap of various cropping and livestock systems, improve resource use efficiencies to control environmental impacts. Furthermore, training and education are needed to increase awarenessand improve skills for farmers and advisers. Our review can serve as example for other global regions that are in transition from unsustainable agriculture production towards sustainable withclean environment and healthy economies

Over the past four decades, China's food security and nutritional status have improved significantly witnessed by elimination of hunger and poverty, increased diversity of diets, and reduction in child stunting. However, the Chinese food systems will face even greater challenges in the future. These include constraints of natural resources, climate change, multiple challenges of malnutrition, food safety, and external shocks from volatile international market. Fortunately, the Chinese government has made important commitments in the ""Fourteenth Five-year Plan"" on food and nutrition security, health, the environment and climate change including achieving carbon neutrality by 2060. The purpose of this brief is to review major achievements and their enabling factors, future challenges and government strategies as well as our recommendations to transform Chinese food systems for both human and planetary health. This paper will help to bring voices of emerging economies like China in setting the global food systems agenda, providing useful insights on the transformation of its own food systems as well as those in other countries.

China's livestock industry has experienced a vast transition during the last three decades, with profound effects on domestic and global food provision, resource use, nitrogen and phosphorus losses, and greenhouse gas (GHG) emissions. We provide a comprehensive analysis of the driving forces around this transition and its national and global consequences. The number of livestock units (LUs) tripled in China in less than 30 years, mainly through the growth of landless industrial livestock production systems and the increase in monogastric livestock (from 62 to 74% of total LUs). Changes were fueled through increases in demand as well as, supply of new breeds, new technology, and government support. Production of animal source protein increased 4.9 times, nitrogen use efficiency at herd level tripled, and average feed use and GHG emissions per gram protein produced decreased by a factor of 2 between 1980 and 2010. In the same period, animal feed imports have increased 49 times, total ammonia and GHG emissions to the atmosphere doubled, and nitrogen losses to watercourses tripled. As a consequence, China's livestock transition has significant global impact. Forecasts for 2050, using the Shared Socio-economic Pathways scenarios, indicate major further changes in livestock production and impacts. On the basis of these possible trajectories, we suggest an alternative transition, which should be implemented by government, processing industries, consumers, and retailers. This new transition is targeted to increase production efficiency and environmental performance at system level, with coupling of crop-livestock production, whole chain manure management, and spatial planning as major components.

China's increasingly urbanized and wealthy population is driving a growing and changing demand for food, which might not be met without significant increase in agricultural productivity and sustainable use of natural resources. Given the past relationship between lack of access to affordable food and political instability, food security has to be given a high priority on national political agendas in the context of globalization. The drive for increased food production has had a significant impact on the environment, and the deterioration in ecosystem quality due to historic and current levels of pollution will potentially compromise the food production system in China. We discuss the grand challenges of not only producing more food but also producing it sustainably and without environmental degradation. In addressing these challenges, food production should be considered as part of an environmental system (soil, air, water, and biodiversity) and not independent from it. It is imperative that new ways of meeting the demand for food are developed while safeguarding the natural resources upon which food production is based. We present a holistic approach to both science and policy to ensure future food security while embracing the ambition of achieving environmental sustainability in China. It is a unique opportunity for China to be a role model as a new global player, especially for other emerging economies.

China's increasingly urbanized and wealthy population is driving a growing and changing demand for food, which might not be met without significant increase in agricultural productivity and sustainable use of natural resources. Given the past relationship between lack of access to affordable food and political instability, food security has to be given a high priority on national political agendas in the context of globalization. The drive for increased food production has had a significant impact on the environment, and the deterioration in ecosystem quality due to historic and current levels of pollution will potentially compromise the food production system in China. We discuss the grand challenges of not only producing more food but also producing it sustainably and without environmental degradation. In addressing these challenges, food production should be considered as part of an environmental system (soil, air, water, and biodiversity) and not independent from it. It is imperative that new ways of meeting the demand for food are developed while safeguarding the natural resources upon which food production is based. We present a holistic approach to both science and policy to ensure future food security while embracing the ambition of achieving environmental sustainability in China. It is a unique opportunity for China to be a role model as a new global player, especially for other emerging economies.

The Chinese government recently proposed ammonia (NH 3 ) emission reductions (but without a specific national target) as a strategic option to mitigate fine particulate matter (PM 2.5 ) pollution. We combined a meta-analysis of nationwide measurements and air quality modeling to identify efficiency gains by striking a balance between controlling NH 3 and acid gas (SO 2 and NO x ) emissions. We found that PM 2.5 concentrations decreased from 2000 to 2019, but annual mean PM 2.5 concentrations still exceeded 35 µ g m −3 at 74 % of 1498 monitoring sites during 2015–2019. The concentration of PM 2.5 and its components were significantly higher (16 %–195 %) on hazy days than on non-hazy days. Compared with mean values of other components, this difference was more significant for the secondary inorganic ions SO 42- , NO 3-

The Chinese government recently proposed ammonia (NH3) emission reductions (but without a specific national target) as a strategic option to mitigate fine particulate matter (PM2.5) pollution. We combined a meta-analysis of nationwide measurements and air quality modeling to identify efficiency gains by striking a balance between controlling NH3 and acid gas (SO2 and NOx) emissions. We found that PM2.5 concentrations decreased from 2000 to 2019, but annual mean PM2.5 concentrations still exceeded 35 µg m−3 at 74 % of 1498 monitoring sites during 2015–2019. The concentration of PM2.5 and its components were significantly higher (16 %–195 %) on hazy days than on non-hazy days. Compared with mean values of other components, this difference was more significant for the secondary inorganic ions SO, NO, and NH (average increase 98 %). While sulfate concentrations significantly decreased over this period, no significant change was observed for nitrate and ammonium concentrations. Model simulations indicate that the effectiveness of a 50 % NH3 emission reduction for controlling secondary inorganic aerosol (SIA) concentrations decreased from 2010 to 2017 in four megacity clusters of eastern China, simulated for the month of January under fixed meteorological conditions (2010). Although the effectiveness further declined in 2020 for simulations including the natural experiment of substantial reductions in acid gas emissions during the COVID-19 pandemic, the resulting reductions in SIA concentrations were on average 20.8 % lower than those in 2017. In addition, the reduction in SIA concentrations in 2017 was greater for 50 % acid gas reductions than for the 50 % NH3 emission reductions. Our findings indicate that persistent secondary inorganic aerosol pollution in China is limited by emissions of acid gases, while an additional control of NH3 emissions would become more important as reductions of SO2 and NOx emissions progress.