In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breedi...In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breeding scale and the demand space for biogas project were analyzed according to the changes in farm scale and farm quantity, the present situation of livestock breeding, the biogas technical pattern and present project quantity in Chengdu. Furthermore, based on the cultivated land area in Chengdu, a principle that ＂land decides production, pro- duction decides fertilizer, and fertilizer decides livestock＂ was proposed, and a pro- gram for the livestock quantity and biogas projects in Chengdu in ＂The 13th Five- Year＂ was suggested. Suggestions were also made for government to modify the allowance standards for biogas project construction.展开更多
Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources....Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources. Taking widely used areas of Shandong Province in China as examples, an analytical scale and level framework for SICL is constructed in this study. It measures the level of SICL through material flow analysis, constructs Tobit models to analyze the influencing factors of SICL at the farming household scale,and analyzes the transition mechanisms of SICL. The results show that the overall level of SICL in Shandong Province is low, and the spatial distribution is uneven. There are relatively more farmers participating in unsustainable intensification than in medium or low levels of SICL, with farmers working at a high level of SICL making up the smallest proportion. The factors that determine the level of SICL at which farmers work vary significantly. More male farmers operate at a low SICL level than female farmers, while females outnumber males at a high SICL level. This is mainly related to the regional distribution of age and population. Meanwhile, with larger cultivated land areas, there is a lower degree of land fragmentation, with a higher level of SICL corresponding to a smaller distance to the nearest town closer within 1–5 km from the town center. We can see the level of SICL and its processes themselves are closely related to time and space scales. Based on the above analysis, it is necessary to clarify the standard processes of SICL to adapt them to local conditions. This includes instructing managers on how to improve resource utilization, increase the sustainable development of cultivated land and establish a comprehensively efficient and functional SICL mechanism. The sustainable intensification of cultivated land use and its specific application in the new era are conducive to enriching the frontier theories and methodology of sustainable development, and are of great significance to the advancement of green agriculture and the decision-making of rural high-quality development.展开更多
Covering the slurry pit has been shown to be one of the best ways to reduce ammonia emissions (NH<sub>3</sub>) during manure management. Yet, few studies have been conducted at farm scale. We studied the f...Covering the slurry pit has been shown to be one of the best ways to reduce ammonia emissions (NH<sub>3</sub>) during manure management. Yet, few studies have been conducted at farm scale. We studied the feasibility of three cover materials (peat, polystyrene balls and synthetic sheet roof) to reduce ammonia (NH<sub>3</sub>) emissions during on-farm storage of pig slurry. The impact on greenhouse gas emissions, methane (CH<sub>4</sub>), nitrous oxide (N<sub>2</sub>O) and carbon dioxide (CO<sub>2</sub>) of covering the slurry pit was also evaluated. Simultaneous field experiments were carried out using two similar pits at a farm with peat and polystyrene ball covers, which allowed direct comparison of the feasibility of the two covers to reduce gas emissions (measured using the dynamic chamber technique). Emissions from the third option (using a synthetic sheet roof) were estimated by measuring the concentrations in the headspace under the cover and the air leakage from the cover with a tracer gas (CO<sub>2</sub>). Results showed that the polystyrene balls cover reduced emissions of NH<sub>3</sub> during storage by up to 80% whatever the season, but increased potential greenhouse gas emissions by 20% in summer. No consistent reduction was achieved with the peat cover even though some individual results seemed to indicate up to 25% reduction in ammonia emissions;moreover, there was a 30% increase in CH<sub>4</sub> and CO<sub>2</sub> emissions during the storage period. The use of a synthetic sheet roof enabled up to 90% reduction in NH<sub>3</sub>, CH<sub>4</sub> and CO<sub>2</sub> emissions whatever the season.展开更多
Based on surveying the conditions of large -scale farms and commercial manure in the each county of Yangzhou city, the situations and problems for utilization of livestock manure resources were grasped. After an analy...Based on surveying the conditions of large -scale farms and commercial manure in the each county of Yangzhou city, the situations and problems for utilization of livestock manure resources were grasped. After an analysis of the potential value of livestock manure, the suggestion and strategy for utilization of livestock manure resources were proposed based on the actual conditions in Yangzhou city.展开更多
The moderate scale family farm is the future agricultural business entity in China,and the scale of family farm is a key factor affecting its development.With Guigang City in Guangxi as a point for the study,from the ...The moderate scale family farm is the future agricultural business entity in China,and the scale of family farm is a key factor affecting its development.With Guigang City in Guangxi as a point for the study,from the perspective of maximizing income of rural households,this paper uses production function model to calculate the moderate scale of food-production-based family farm at 5.7 ha,and makes policy recommendations.展开更多
China's dairy farming has presented a striking development in recent years.Under the dual constraints of environment and resources,it is of practical significance to increase the output of dairy farming and ensure...China's dairy farming has presented a striking development in recent years.Under the dual constraints of environment and resources,it is of practical significance to increase the output of dairy farming and ensure the healthy and stable development of the dairy industry,by accurately comparing the differences in the farming efficiency of dairy farms at different scales and grasping key factors influencing the farming efficiency.This study,through the cost analysis of 263 scale farms across 23 provinces and regions of China in 2019,reaches a result that the cost of a single cow in a certain scale farm increases with the enlargement of the scale,and shows an inverted-U shaped curve with the relatively large scales(1001-2000 cows)at the highest point.It measures the farming efficiency of dairy farms at different scales through the data envelopment analysis and finds that the scale efficiency and allocation efficiency of scale farms in China are relatively high,while the technology efficiency and cost efficiency are relatively low.The efficiency of different scale farms is obviously different,where the cost efficiency,allocation efficiency and scale efficiency show a U-shaped curve as the scale enlarges(with the relatively large scale as the lowest point),while the technology efficiency gradually decreases as the scale expands.It is concluded that for the scale farms,feed conversion ratio and forage-to-concentrate ratio have a significantly negative impact on the scale efficiency,while the labor cost,number of employees,and depreciation of fixed assets are negatively correlated to the technology efficiency and cost efficiency of dairy farming.展开更多
The spatial distribution of wind speed varies greatly over steep complex terrain, thus the selection of an optimal site in such terrain for wind turbine construction requires great care. We have developed a numerical ...The spatial distribution of wind speed varies greatly over steep complex terrain, thus the selection of an optimal site in such terrain for wind turbine construction requires great care. We have developed a numerical model for simulating unsteady flows called RIAM-COMPACT (Research Institute for Applied Mechanics, Kyushu University, COM putational Prediction of Airflow over Complex Terrain), which is based on the LES (Large-Eddy Simulation) technique. The computational domain of RIAM-COMPACT can be varied from several meters to several kilometers, and the model is able to predict airflow over complex terrain with high accuracy. The present paper discusses the application of RIAM-COMPACT to the micro-siting of wind turbines at sites outside Japan. The results from two case studies will be presented.展开更多
文摘In order to implement National Sustainable Development of Agriculture 2015-2030 and supply-side reform of agriculture, and seek the way to replace chemical fertilizer by livestock and poultry manure, the animal breeding scale and the demand space for biogas project were analyzed according to the changes in farm scale and farm quantity, the present situation of livestock breeding, the biogas technical pattern and present project quantity in Chengdu. Furthermore, based on the cultivated land area in Chengdu, a principle that ＂land decides production, pro- duction decides fertilizer, and fertilizer decides livestock＂ was proposed, and a pro- gram for the livestock quantity and biogas projects in Chengdu in ＂The 13th Five- Year＂ was suggested. Suggestions were also made for government to modify the allowance standards for biogas project construction.
基金Under the auspices of the National Natural Science Foundation of China(No.41671176,42071226)Liaoning Revitalization Talents Program(No.XLYC1807060)。
文摘Promoting the sustainable intensification of cultivated land use(SICL) has become crucial for ensuring a sufficient supply of grain and important agricultural products, as well as for the sustainable use of resources. Taking widely used areas of Shandong Province in China as examples, an analytical scale and level framework for SICL is constructed in this study. It measures the level of SICL through material flow analysis, constructs Tobit models to analyze the influencing factors of SICL at the farming household scale,and analyzes the transition mechanisms of SICL. The results show that the overall level of SICL in Shandong Province is low, and the spatial distribution is uneven. There are relatively more farmers participating in unsustainable intensification than in medium or low levels of SICL, with farmers working at a high level of SICL making up the smallest proportion. The factors that determine the level of SICL at which farmers work vary significantly. More male farmers operate at a low SICL level than female farmers, while females outnumber males at a high SICL level. This is mainly related to the regional distribution of age and population. Meanwhile, with larger cultivated land areas, there is a lower degree of land fragmentation, with a higher level of SICL corresponding to a smaller distance to the nearest town closer within 1–5 km from the town center. We can see the level of SICL and its processes themselves are closely related to time and space scales. Based on the above analysis, it is necessary to clarify the standard processes of SICL to adapt them to local conditions. This includes instructing managers on how to improve resource utilization, increase the sustainable development of cultivated land and establish a comprehensively efficient and functional SICL mechanism. The sustainable intensification of cultivated land use and its specific application in the new era are conducive to enriching the frontier theories and methodology of sustainable development, and are of great significance to the advancement of green agriculture and the decision-making of rural high-quality development.
文摘Covering the slurry pit has been shown to be one of the best ways to reduce ammonia emissions (NH<sub>3</sub>) during manure management. Yet, few studies have been conducted at farm scale. We studied the feasibility of three cover materials (peat, polystyrene balls and synthetic sheet roof) to reduce ammonia (NH<sub>3</sub>) emissions during on-farm storage of pig slurry. The impact on greenhouse gas emissions, methane (CH<sub>4</sub>), nitrous oxide (N<sub>2</sub>O) and carbon dioxide (CO<sub>2</sub>) of covering the slurry pit was also evaluated. Simultaneous field experiments were carried out using two similar pits at a farm with peat and polystyrene ball covers, which allowed direct comparison of the feasibility of the two covers to reduce gas emissions (measured using the dynamic chamber technique). Emissions from the third option (using a synthetic sheet roof) were estimated by measuring the concentrations in the headspace under the cover and the air leakage from the cover with a tracer gas (CO<sub>2</sub>). Results showed that the polystyrene balls cover reduced emissions of NH<sub>3</sub> during storage by up to 80% whatever the season, but increased potential greenhouse gas emissions by 20% in summer. No consistent reduction was achieved with the peat cover even though some individual results seemed to indicate up to 25% reduction in ammonia emissions;moreover, there was a 30% increase in CH<sub>4</sub> and CO<sub>2</sub> emissions during the storage period. The use of a synthetic sheet roof enabled up to 90% reduction in NH<sub>3</sub>, CH<sub>4</sub> and CO<sub>2</sub> emissions whatever the season.
基金Cultivated Land Quality Monitoring Special Funds in Jiangsu Province,Jiangsu Agricultural Three Engineerings(sx(2010)229)Yangzhou Agricultural Science and Technology Project(YZ2010059)Aid
文摘Based on surveying the conditions of large -scale farms and commercial manure in the each county of Yangzhou city, the situations and problems for utilization of livestock manure resources were grasped. After an analysis of the potential value of livestock manure, the suggestion and strategy for utilization of livestock manure resources were proposed based on the actual conditions in Yangzhou city.
基金Supported by Scientific Research Project of Guangxi Universities in 2015
文摘The moderate scale family farm is the future agricultural business entity in China,and the scale of family farm is a key factor affecting its development.With Guigang City in Guangxi as a point for the study,from the perspective of maximizing income of rural households,this paper uses production function model to calculate the moderate scale of food-production-based family farm at 5.7 ha,and makes policy recommendations.
基金the Fund for Technological Innovation Project"Evaluation of Transformation Efficiency of Green Animal Husbandry Technology Achievements:Taking Dairy Industry as an Example".
文摘China's dairy farming has presented a striking development in recent years.Under the dual constraints of environment and resources,it is of practical significance to increase the output of dairy farming and ensure the healthy and stable development of the dairy industry,by accurately comparing the differences in the farming efficiency of dairy farms at different scales and grasping key factors influencing the farming efficiency.This study,through the cost analysis of 263 scale farms across 23 provinces and regions of China in 2019,reaches a result that the cost of a single cow in a certain scale farm increases with the enlargement of the scale,and shows an inverted-U shaped curve with the relatively large scales(1001-2000 cows)at the highest point.It measures the farming efficiency of dairy farms at different scales through the data envelopment analysis and finds that the scale efficiency and allocation efficiency of scale farms in China are relatively high,while the technology efficiency and cost efficiency are relatively low.The efficiency of different scale farms is obviously different,where the cost efficiency,allocation efficiency and scale efficiency show a U-shaped curve as the scale enlarges(with the relatively large scale as the lowest point),while the technology efficiency gradually decreases as the scale expands.It is concluded that for the scale farms,feed conversion ratio and forage-to-concentrate ratio have a significantly negative impact on the scale efficiency,while the labor cost,number of employees,and depreciation of fixed assets are negatively correlated to the technology efficiency and cost efficiency of dairy farming.
文摘The spatial distribution of wind speed varies greatly over steep complex terrain, thus the selection of an optimal site in such terrain for wind turbine construction requires great care. We have developed a numerical model for simulating unsteady flows called RIAM-COMPACT (Research Institute for Applied Mechanics, Kyushu University, COM putational Prediction of Airflow over Complex Terrain), which is based on the LES (Large-Eddy Simulation) technique. The computational domain of RIAM-COMPACT can be varied from several meters to several kilometers, and the model is able to predict airflow over complex terrain with high accuracy. The present paper discusses the application of RIAM-COMPACT to the micro-siting of wind turbines at sites outside Japan. The results from two case studies will be presented.
