At present, food safety and agricultural pollution arouse public attention. Developing organic agriculture, therefore, is a feasible approach to solve related problems. Caijia wa is a base of organic agricultural prod...At present, food safety and agricultural pollution arouse public attention. Developing organic agriculture, therefore, is a feasible approach to solve related problems. Caijia wa is a base of organic agricultural products of Miyun County in Beijing. Based on the experience of farm management of Taiwan, Caijiawa's char- acteristics were explored. Customer requests were collected and analyzed to find growth space of new market. To establish marketing system for Caijia wa Base, three questions should be settled at the very begining. The questions are as fol- lows: Who are the customers to be confronted with? What's kind of product or service can we provide? What are the causes that customers willing to pay a prod- uct at higher price? On basis of experience in Taiwan and local characters, the marketing system in Caijia wa Base can be concluded, including segmentation of market, diversification of marketing channel, close contact with clients and flexibility of price system. The pattern of omni-directional, muti-level and wide-ranging cooper- ation has been improved continuously. Finally, marketing system could integrate with social responsibility and sustainable development. Some measures about the marketing system have been proposed, which are believed applicable to other bases of organic agriculture.展开更多
A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil wa...A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil was puddled and cropped under submerged conditions. Among all treatments, soil organic matter contents in the treatments of rice-rice-flooded fallow in winter (WF) were the highest, those in the treatments of rice-rice-astragalus (WG) came the second, and those in the treatments of rice-rice-rape (WR)were the lowest. At the same rate of green manure application, the degrees of organo-mineral complexing in soils of treatments WG and WR were higher than those of treatment WF. After 9-year rice cultivation, the state of combination of humus in heavy fraction varied with treatments. The relative content of loosely bonded humus decreased in the order of WR > WG > WF, and it correlated significantly with Se availability.展开更多
This paper presents the automatic guidance system of an agricultural tractor and the side shift control of the attached row crop cultivator using electro-hydraulic actuators. In order to simulate the dynamic behaviour...This paper presents the automatic guidance system of an agricultural tractor and the side shift control of the attached row crop cultivator using electro-hydraulic actuators. In order to simulate the dynamic behaviour of the tractor along with the attached cultivator, the modified bicycle model was adopted. Steering angle sensor, fibre optic gyroscope (FOG) and RTK-DGPS technologies are assumed for measurements of the steering angle, yaw rate and the lateral position of the tractor, respectively. The kinematics model was used for the implement. In this study four cascade controllers were designed and simulated for tractor guidance which consists ofPD, PD, P and PID controllers. Other PI and PID controllers also had been designed for implement side shifting purpose. Then, these two systems were combined and the performance of the whole system was evaluated through the simulation results. According to the results tractor reaches the desired path after less than 10 seconds. Simulations showed that the maximum deviation of the tractor from the desired path was about 5 cm within this period. And the cultivator blades would follow the predetermined path with steady state error of about 5 cm too.展开更多
Organic vegetables, does not use pesticides, synthetic fertilizers, herbicides, growth regulators in production process and refers to organisms and products got from genetic engineering. It follows the laws of nature ...Organic vegetables, does not use pesticides, synthetic fertilizers, herbicides, growth regulators in production process and refers to organisms and products got from genetic engineering. It follows the laws of nature and ecological principles, adopts a series of sustainable development of agricultural technology, to coordinate planting balanced, and stable agricultural ecosystems, and through the identification of organic certification, it will be recognized and awarded organic certification. Beijing Country Fair launched by a group of consumer volunteers concerned about ecological agriculture and rural issues, aiming to build a platform for farmers engaged in organic agriculture and consumers can communicate directly, exchange. It can help consumers find safe, assured products, but also help farmers to broaden market channels and encourage more farmers to engage in organic farming, thereby reducing environmental pollution produced by fertilizer and pesticide, safeguarding food security, and practicing fair trade.展开更多
The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified (GM) crops production. In the European Uni...The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified (GM) crops production. In the European Union, there are no form of agriculture, whether conventional, organic or transgenic, should be excluded. Farmers are free to choose the production type they prefer, without being forced to change patterns already established in the area and without spending more resources. The European Commission defines the term coexistence as the farmers' ability to make a practical choice between conventional, organic and GM crop production, in compliance with the legal obligations for labelling and/or purity standards. In simple terms, coexistence is a way of allowing farmers to choose between the three agricultural systems. Farmers' choice of growing GM or non-GM crops depends not only on technical aspects related to the productivity gains and agronomic benefits to be gained from adopting this technology, but also on consumers' preferences. Particularly in Europe, consumers continue to be concerned about the potentially adverse implications of widespread GM crop production for the environment and food safety. Today only 16 Member States have adopted specific legislation on coexistence. Denmark was the first European Country that, in 2004, adopted a coexistence law and it is currently the coexistence reference model in all the European Union.展开更多
The number of electronic devices connected to agricultural machinery is increasing to support new agricultural practices tasks related to the Precision Agriculture such as spatial variability mapping and Variable Rate...The number of electronic devices connected to agricultural machinery is increasing to support new agricultural practices tasks related to the Precision Agriculture such as spatial variability mapping and Variable Rate Technology (VRT). The Distributed Control System (DCS) is a suitable solution for decentralization of the data acquisition system and the Controller Area Network (CAN) is the major trend among the embedded communications protocols for agricultural machinery and vehicles. The application of soil correctives is a typical problem in Brazil. The efficiency of this correction process is highly dependent of the inputs way at soil and the occurrence of errors affects directly the agricultural yield. To handle this problem, this paper presents the development of a CAN-based distributed control system for a VRT system of soil corrective in agricultural machinery. The VRT system is composed by a tractor-implement that applies a desired rate of inputs according to the georeferenced prescription map of the farm field to support PA (Precision Agriculture). The performance evaluation of the CAN-based VRT system was done by experimental tests and analyzing the CAN messages transmitted in the operation of the entire system. The results of the control error according to the necessity of agricultural application allow conclude that the developed VRT system is suitable for the agricultural productions reaching an acceptable response time and application error. The CAN-Based DCS solution applied in the VRT system reduced the complexity of the control system, easing the installation and maintenance. The use of VRT system allowed applying only the required inputs, increasing the efficiency operation and minimizing the environmental impact.展开更多
Worldwide, there is a growing demand for products made by technologies that contribute to environmental preservation and to sustainable rural development. In Brazil, organic farming is one of the most established init...Worldwide, there is a growing demand for products made by technologies that contribute to environmental preservation and to sustainable rural development. In Brazil, organic farming is one of the most established initiatives in this area. Therefore, it is important to subsidize the decision-making regarding policies for organic coffee production. Thereby, this study analyzed the socio-economic sustainability of this production system in relation to conventional. We applied a semi-structured questionnaire on coffee farms in the Brazilian coffee producers states and analyzed the coffee production cost structure. We identified the reasons that led the producers to organic management, implications of certification on the management, and prices received by organic coffee and the market mechanism. Results showed that there is no standard for organic coffee production and marketing in Brazil. Among the producers, there are different levels of access to technical information and the main limitation of the organic coffee chain is not the technology of production, but the difficulty of coffee marketing. Another important limitation, for medium and large farms, is the cost of manpower, mainly in areas dominated by mountain, where machines operations are not viable. Moreover, the yield of organic coffee system is generally lower than the conventional. Furthermore, soil and climatic differences lead to different regional behavior. Finally, we could conclude that the production of organic coffee can be sustainable in Brazil mainly in two structural conditions: 1) family farmers; and 2) small producers, who employ only one or two workers, preferably only in the harvest time.展开更多
With the improvement of agricultural mechanization equipment levels, the mechanized wheat harvesting level has been above 80% and the rate of wheat straw returned has increased significantly in the main wheat producti...With the improvement of agricultural mechanization equipment levels, the mechanized wheat harvesting level has been above 80% and the rate of wheat straw returned has increased significantly in the main wheat production of wheat of northern countryside in China. Chinese government popularized the beneficial agronomic measures in the process of wheat straw returned field by mechanization. The agronomic measure was reducing the wheat straw stubble height(WSSH) not more than 20 cm.However, local government didn't apply and disseminate the measure, because in practice the cost of fuel consumption was high, and the operation time of harvesting was longer than ever. The machinery operators and farmers needed to support extra fuel cost and time if they took government's advice. In fact, the objective subsidy policy of fuel cost on reducing WSSH was not been formulated by all levels of government. Therefore, the set of agronomic measure couldn't be popularized in main wheat production area of North China. Our research addressed to master the changing feature of fuel cost and mechanical efficiency,seeking suitable subsidy standard, providing some useful and constructive suggestions to improve subsidy policy of fuel consumption cost for national government department. The study carried out the tracking experiments of the operation efficiency and fuel costs of farm harvester in the situation of different WSSH in 2010 in Xushui District of Hebei Province. In conclusion, the operation time of harvesting decline and machinery fuel consumption cost increased along with the decreasing of WSSH. First for the older harvester, the operation efficiency would decline by 18.7% when the WSSH changed from 20 cm to 10 cm, the cost would increase 4.7%, exact cost was 152.2CNY per hectare. For the new harvester, the operation efficiency would decline by 39.9% when the WSSH changed from 20 cm to 15 cm, the cost would increase 4.6%, exact cost was 368.4CNY per hectare. We provided about 375 CNY per hectare to the mechanical operators and farmer who attended this project, and they were willing to accept the subsidies. We also put forwards some policy suggestions on promoting agronomic measures of reducing WSSH including strengthen the construction of agricultural machinery service system, practise a special fuel consumption subsidies of agricultural machinery and open up new paths for combine sales and circulation.展开更多
A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the...A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the existing system for the needed tractor-implement performance, measurements. This system is capable of measuring, displaying and recording, in real-time, the tractor's theoretical travel speed, the actual travel speed, the engine speed, the fuel consumption rate, and the drawbar pull. Static calibration tests on various associated sensors for the required measurements show excellent linearity with correlation coefficients that are close to 1. The developed system was extensively and successfully field demonstrated for tractor-implement performance with offset disc harrows on dry, undisturbed loamy soils. Under these conditions, a ratio of tractor power to implement width is suggested. The data also show the existence of a linear relationship between fuel consumption per hectare and specific draught, for the 4 to 9 kN m^-1 range, which suggests the possibility of extending the American Society of Agricultural and Biological Engineers model of draught prediction to forecast fuel consumption. The configuration of the tractor-harrow combination, based on the measurement of the draught required under operational conditions, provides the manufacturers with a reliable indication of the recommended power required for each harrow model. With this type of information farmers can make decisions regarding selection of a suitable tractor-implement combination for their farms. As a consequence, there is improved tractor-harrow productivity and field efficiency.展开更多
In this study, tractor power output, fuel consumption rate and work performance were indirectly predicted in order to develop an eco driving system. Firstly, equations were developed which could foretell tractor power...In this study, tractor power output, fuel consumption rate and work performance were indirectly predicted in order to develop an eco driving system. Firstly, equations were developed which could foretell tractor power output and fuel consumption rate using characteristic curves of tractor power output. Secondly, with actual engine revolution per minute (rpm) determined by initial engine rpm and work load, tractor power output and fuel consumption rate were forecasted. Thirdly, it was possible to foresee tractor work performance and fuel consumption rate by the speed signals of Global Positioning System (GPS). Lastly, precision of the eco driving system was evaluated through tractor Power Take-Off (PTO) test, and effects of the eco driving system were investigated in the plowing and rotary tilling operations. Engine rpm, power output, fuel consumption rate, work performance and fuel consumption rate per plot area were displayed on the eco driving system. Predicted tractor power outputs in the full load curve were well coincided with the actual power output of prototype, but small differences, 1 to 6 kW were found in the part load curve. Error of the fuel consumption rate was 0.5 to 3 L/h at the part load curve. It was shown that 69% and 53% of fuel consumption rates could be reduced in plowing and rotary tilling operations, respectively, when the eco driving system was installed in tractor.展开更多
Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era ...Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.展开更多
Producing of renewable energy--as well in world as in national context--was necessitated by the synergistic effect of the climate change and the long term, continuous price rise of the fossil energy carriers. Main rea...Producing of renewable energy--as well in world as in national context--was necessitated by the synergistic effect of the climate change and the long term, continuous price rise of the fossil energy carriers. Main reasons for the spread of renewable energy sources are to increase the security of the energy supply or in optimal case, to realize the total energy independence. Furthermore, numerous studies demonstrate that production and also utilization of biofuels--including the organic waste-based fuels--are environmentally sustainable and have positive impact for the security of energy supply. This paper deals with production of biogas (from agricultural organic wastes) for energy. The production of biogas and the other biofuels will help you find the balance in agriculture because they can be generated from biomass, agricultural wastes and non-food plant material. In addition to the objective of saving emissions, EU biofuels policy aims to ensure the necessary energy and to decrease unemployment. So this paper would like to contribute to the EU requirements through the research. The producing system can be expansible by utilization of other organic material, so it is supported the efficient operation.展开更多
In rural area of sub-Saharan Africa, the electrification rate is only 23%. There are isolated diesel power stations in sub-Saharan countries. However, power production by diesel generator is relatively high compared t...In rural area of sub-Saharan Africa, the electrification rate is only 23%. There are isolated diesel power stations in sub-Saharan countries. However, power production by diesel generator is relatively high compared to that of national grid. In addition, public facilities such as rural school and health clinic have important role inproviding adequate public services in non-electrified communities. Therefore, in order to reduce power production cost, optimum configuration of the wind diesel hybrid generation system and the economic feasibility were studied. In the study, operational data of the existing diesel generator and wind potential were analyzed and optimum configuration of wind and diesel hybrid system was proposed. In addition, economic feasibility study of the hybrid system was conducted. In the result, EIRR (economic internal rate of return) of the proposed wind-diesel hybrid power plant was obtained as 10%.展开更多
The rice-wheat rotation in southern China is characterized by frequent flooding-draining water regime and heavy nitrogen(N)fertilization. There is a substantial lack of studies into the behavior of dissolved organic n...The rice-wheat rotation in southern China is characterized by frequent flooding-draining water regime and heavy nitrogen(N)fertilization. There is a substantial lack of studies into the behavior of dissolved organic nitrogen(DON) in the intensively managed agroecosystem. A 3-year in situ field experiment was conducted to determine DON leaching and its seasonal and yearly variations as affected by fertilization, irrigation and precipitation over 6 consecutive rice/wheat seasons. Under the conventional N practice(300kg N ha-1for rice and 200 kg N ha-1for wheat), the seasonal average DON concentrations in leachate(100 cm soil depth) for the three rice and wheat seasons were 0.6–1.1 and 0.1–2.3 mg N L-1, respectively. The cumulative DON leaching was estimated to be1.1–2.3 kg N ha-1for the rice seasons and 0.01–1.3 kg N ha-1for the wheat seasons, with an annual total of 1.1–3.6 kg N ha-1. In the rice seasons, N fertilizer had little effect(P > 0.05) on DON leaching; precipitation and irrigation imported 3.6–9.1 kg N ha-1of DON, which may thus conceal the fertilization effect on DON. In the wheat seasons, N fertilization had a positive effect(P < 0.01)on DON. Nevertheless, this promotive effect was strongly influenced by variable precipitation, which also carried 1.8–2.9 kg N ha-1of DON into fields. Despite a very small proportion to chemical N applied and large variations driven by water regime, DON leaching is necessarily involved in the integrated field N budget in the rice-wheat rotation due to its relatively greater amount compared to other natural ecosystems.展开更多
基金Supported by Social Science Research Common Program of Beijing Municipal Commission of Education(SM201110017001)~~
文摘At present, food safety and agricultural pollution arouse public attention. Developing organic agriculture, therefore, is a feasible approach to solve related problems. Caijia wa is a base of organic agricultural products of Miyun County in Beijing. Based on the experience of farm management of Taiwan, Caijiawa's char- acteristics were explored. Customer requests were collected and analyzed to find growth space of new market. To establish marketing system for Caijia wa Base, three questions should be settled at the very begining. The questions are as fol- lows: Who are the customers to be confronted with? What's kind of product or service can we provide? What are the causes that customers willing to pay a prod- uct at higher price? On basis of experience in Taiwan and local characters, the marketing system in Caijia wa Base can be concluded, including segmentation of market, diversification of marketing channel, close contact with clients and flexibility of price system. The pattern of omni-directional, muti-level and wide-ranging cooper- ation has been improved continuously. Finally, marketing system could integrate with social responsibility and sustainable development. Some measures about the marketing system have been proposed, which are believed applicable to other bases of organic agriculture.
文摘A long-term simulation experiment was carried out to study the effect of rice-based cropping system,green manure and ground-water level on soil organic matter. Soil organic matter content increased when upland soil was puddled and cropped under submerged conditions. Among all treatments, soil organic matter contents in the treatments of rice-rice-flooded fallow in winter (WF) were the highest, those in the treatments of rice-rice-astragalus (WG) came the second, and those in the treatments of rice-rice-rape (WR)were the lowest. At the same rate of green manure application, the degrees of organo-mineral complexing in soils of treatments WG and WR were higher than those of treatment WF. After 9-year rice cultivation, the state of combination of humus in heavy fraction varied with treatments. The relative content of loosely bonded humus decreased in the order of WR > WG > WF, and it correlated significantly with Se availability.
文摘This paper presents the automatic guidance system of an agricultural tractor and the side shift control of the attached row crop cultivator using electro-hydraulic actuators. In order to simulate the dynamic behaviour of the tractor along with the attached cultivator, the modified bicycle model was adopted. Steering angle sensor, fibre optic gyroscope (FOG) and RTK-DGPS technologies are assumed for measurements of the steering angle, yaw rate and the lateral position of the tractor, respectively. The kinematics model was used for the implement. In this study four cascade controllers were designed and simulated for tractor guidance which consists ofPD, PD, P and PID controllers. Other PI and PID controllers also had been designed for implement side shifting purpose. Then, these two systems were combined and the performance of the whole system was evaluated through the simulation results. According to the results tractor reaches the desired path after less than 10 seconds. Simulations showed that the maximum deviation of the tractor from the desired path was about 5 cm within this period. And the cultivator blades would follow the predetermined path with steady state error of about 5 cm too.
文摘Organic vegetables, does not use pesticides, synthetic fertilizers, herbicides, growth regulators in production process and refers to organisms and products got from genetic engineering. It follows the laws of nature and ecological principles, adopts a series of sustainable development of agricultural technology, to coordinate planting balanced, and stable agricultural ecosystems, and through the identification of organic certification, it will be recognized and awarded organic certification. Beijing Country Fair launched by a group of consumer volunteers concerned about ecological agriculture and rural issues, aiming to build a platform for farmers engaged in organic agriculture and consumers can communicate directly, exchange. It can help consumers find safe, assured products, but also help farmers to broaden market channels and encourage more farmers to engage in organic farming, thereby reducing environmental pollution produced by fertilizer and pesticide, safeguarding food security, and practicing fair trade.
文摘The objective of this research is to analyse the way of the European Union is addressing the issue of the coexistence between conventional, organic and Genetically Modified (GM) crops production. In the European Union, there are no form of agriculture, whether conventional, organic or transgenic, should be excluded. Farmers are free to choose the production type they prefer, without being forced to change patterns already established in the area and without spending more resources. The European Commission defines the term coexistence as the farmers' ability to make a practical choice between conventional, organic and GM crop production, in compliance with the legal obligations for labelling and/or purity standards. In simple terms, coexistence is a way of allowing farmers to choose between the three agricultural systems. Farmers' choice of growing GM or non-GM crops depends not only on technical aspects related to the productivity gains and agronomic benefits to be gained from adopting this technology, but also on consumers' preferences. Particularly in Europe, consumers continue to be concerned about the potentially adverse implications of widespread GM crop production for the environment and food safety. Today only 16 Member States have adopted specific legislation on coexistence. Denmark was the first European Country that, in 2004, adopted a coexistence law and it is currently the coexistence reference model in all the European Union.
文摘The number of electronic devices connected to agricultural machinery is increasing to support new agricultural practices tasks related to the Precision Agriculture such as spatial variability mapping and Variable Rate Technology (VRT). The Distributed Control System (DCS) is a suitable solution for decentralization of the data acquisition system and the Controller Area Network (CAN) is the major trend among the embedded communications protocols for agricultural machinery and vehicles. The application of soil correctives is a typical problem in Brazil. The efficiency of this correction process is highly dependent of the inputs way at soil and the occurrence of errors affects directly the agricultural yield. To handle this problem, this paper presents the development of a CAN-based distributed control system for a VRT system of soil corrective in agricultural machinery. The VRT system is composed by a tractor-implement that applies a desired rate of inputs according to the georeferenced prescription map of the farm field to support PA (Precision Agriculture). The performance evaluation of the CAN-based VRT system was done by experimental tests and analyzing the CAN messages transmitted in the operation of the entire system. The results of the control error according to the necessity of agricultural application allow conclude that the developed VRT system is suitable for the agricultural productions reaching an acceptable response time and application error. The CAN-Based DCS solution applied in the VRT system reduced the complexity of the control system, easing the installation and maintenance. The use of VRT system allowed applying only the required inputs, increasing the efficiency operation and minimizing the environmental impact.
文摘Worldwide, there is a growing demand for products made by technologies that contribute to environmental preservation and to sustainable rural development. In Brazil, organic farming is one of the most established initiatives in this area. Therefore, it is important to subsidize the decision-making regarding policies for organic coffee production. Thereby, this study analyzed the socio-economic sustainability of this production system in relation to conventional. We applied a semi-structured questionnaire on coffee farms in the Brazilian coffee producers states and analyzed the coffee production cost structure. We identified the reasons that led the producers to organic management, implications of certification on the management, and prices received by organic coffee and the market mechanism. Results showed that there is no standard for organic coffee production and marketing in Brazil. Among the producers, there are different levels of access to technical information and the main limitation of the organic coffee chain is not the technology of production, but the difficulty of coffee marketing. Another important limitation, for medium and large farms, is the cost of manpower, mainly in areas dominated by mountain, where machines operations are not viable. Moreover, the yield of organic coffee system is generally lower than the conventional. Furthermore, soil and climatic differences lead to different regional behavior. Finally, we could conclude that the production of organic coffee can be sustainable in Brazil mainly in two structural conditions: 1) family farmers; and 2) small producers, who employ only one or two workers, preferably only in the harvest time.
基金Supported by National Nonprofit Institute Research Grant of CAAS(IARRP-2015-7)Key Laboratory of Nonpoint Source Pollution Control,Ministry of Agriculture,P.R.China,Chinese Academy of Agricultural Sciences Science and Technology Innovation Project in 2017the Public Welfare Industry Science and Technology Projects for financing the research (no.200903011)
文摘With the improvement of agricultural mechanization equipment levels, the mechanized wheat harvesting level has been above 80% and the rate of wheat straw returned has increased significantly in the main wheat production of wheat of northern countryside in China. Chinese government popularized the beneficial agronomic measures in the process of wheat straw returned field by mechanization. The agronomic measure was reducing the wheat straw stubble height(WSSH) not more than 20 cm.However, local government didn't apply and disseminate the measure, because in practice the cost of fuel consumption was high, and the operation time of harvesting was longer than ever. The machinery operators and farmers needed to support extra fuel cost and time if they took government's advice. In fact, the objective subsidy policy of fuel cost on reducing WSSH was not been formulated by all levels of government. Therefore, the set of agronomic measure couldn't be popularized in main wheat production area of North China. Our research addressed to master the changing feature of fuel cost and mechanical efficiency,seeking suitable subsidy standard, providing some useful and constructive suggestions to improve subsidy policy of fuel consumption cost for national government department. The study carried out the tracking experiments of the operation efficiency and fuel costs of farm harvester in the situation of different WSSH in 2010 in Xushui District of Hebei Province. In conclusion, the operation time of harvesting decline and machinery fuel consumption cost increased along with the decreasing of WSSH. First for the older harvester, the operation efficiency would decline by 18.7% when the WSSH changed from 20 cm to 10 cm, the cost would increase 4.7%, exact cost was 152.2CNY per hectare. For the new harvester, the operation efficiency would decline by 39.9% when the WSSH changed from 20 cm to 15 cm, the cost would increase 4.6%, exact cost was 368.4CNY per hectare. We provided about 375 CNY per hectare to the mechanical operators and farmer who attended this project, and they were willing to accept the subsidies. We also put forwards some policy suggestions on promoting agronomic measures of reducing WSSH including strengthen the construction of agricultural machinery service system, practise a special fuel consumption subsidies of agricultural machinery and open up new paths for combine sales and circulation.
文摘A novel data acquisition system was successfully integrated on-board the Massey Ferguson 3,000 series agricultural tractors for measuring tractor-implement performance. A commercial load cell was incorporated into the existing system for the needed tractor-implement performance, measurements. This system is capable of measuring, displaying and recording, in real-time, the tractor's theoretical travel speed, the actual travel speed, the engine speed, the fuel consumption rate, and the drawbar pull. Static calibration tests on various associated sensors for the required measurements show excellent linearity with correlation coefficients that are close to 1. The developed system was extensively and successfully field demonstrated for tractor-implement performance with offset disc harrows on dry, undisturbed loamy soils. Under these conditions, a ratio of tractor power to implement width is suggested. The data also show the existence of a linear relationship between fuel consumption per hectare and specific draught, for the 4 to 9 kN m^-1 range, which suggests the possibility of extending the American Society of Agricultural and Biological Engineers model of draught prediction to forecast fuel consumption. The configuration of the tractor-harrow combination, based on the measurement of the draught required under operational conditions, provides the manufacturers with a reliable indication of the recommended power required for each harrow model. With this type of information farmers can make decisions regarding selection of a suitable tractor-implement combination for their farms. As a consequence, there is improved tractor-harrow productivity and field efficiency.
文摘In this study, tractor power output, fuel consumption rate and work performance were indirectly predicted in order to develop an eco driving system. Firstly, equations were developed which could foretell tractor power output and fuel consumption rate using characteristic curves of tractor power output. Secondly, with actual engine revolution per minute (rpm) determined by initial engine rpm and work load, tractor power output and fuel consumption rate were forecasted. Thirdly, it was possible to foresee tractor work performance and fuel consumption rate by the speed signals of Global Positioning System (GPS). Lastly, precision of the eco driving system was evaluated through tractor Power Take-Off (PTO) test, and effects of the eco driving system were investigated in the plowing and rotary tilling operations. Engine rpm, power output, fuel consumption rate, work performance and fuel consumption rate per plot area were displayed on the eco driving system. Predicted tractor power outputs in the full load curve were well coincided with the actual power output of prototype, but small differences, 1 to 6 kW were found in the part load curve. Error of the fuel consumption rate was 0.5 to 3 L/h at the part load curve. It was shown that 69% and 53% of fuel consumption rates could be reduced in plowing and rotary tilling operations, respectively, when the eco driving system was installed in tractor.
基金funded by the Federal Ministry of Education and Research (BMBF), Germany
文摘Farmer-managed irrigation systems(FMIS) in the high altitude valleys of the Karakorum,Pakistan, continue to be managed effectively despite increased pressure on the social arrangements that sustain them. Colonial era records shows that over a century ago government agencies undertook irrigation support projects. In the past three decades,government agencies and the non-government agency Aga Khan Rural Support Programme(AKRSP), which channels foreign funds into the region, have actively engaged in the provision of irrigation support. This article seeks to explore whether such projects support or undermine farmer-managed irrigation systems and the complex institutional arrangements that underpin them. Field research using ethnographic and participatory methods was conducted in spring 2013 in the upper Shigar valley, Skardu district, GilgitBaltistan. The findings show that irrigation development is a political activity that involves village-based actors, religious leaders, local politicians,and government and non-government agencies.Government agencies operate in a largely top-down,engineering mode, their larger projects limited to villages suffering water scarcity. The local government provides small funds for renovation work of FMIS,though allocation of funds is highly politicized. Nongovernment agencies, for a variety of reasons including donor-funding cycles, apply a one-size-fitsall ‘participatory' model in an attempt to socially engineer rules and institutions. In communities divided by factionalism the use of such external models that stress formation of committees are unlikely to yield positive results, and could instead contribute to undermining the very systems they seek to support. This research argues that irrigation interventions should take care to build upon the rich and complex social arrangements that have sustained FMIS through the centuries.
文摘Producing of renewable energy--as well in world as in national context--was necessitated by the synergistic effect of the climate change and the long term, continuous price rise of the fossil energy carriers. Main reasons for the spread of renewable energy sources are to increase the security of the energy supply or in optimal case, to realize the total energy independence. Furthermore, numerous studies demonstrate that production and also utilization of biofuels--including the organic waste-based fuels--are environmentally sustainable and have positive impact for the security of energy supply. This paper deals with production of biogas (from agricultural organic wastes) for energy. The production of biogas and the other biofuels will help you find the balance in agriculture because they can be generated from biomass, agricultural wastes and non-food plant material. In addition to the objective of saving emissions, EU biofuels policy aims to ensure the necessary energy and to decrease unemployment. So this paper would like to contribute to the EU requirements through the research. The producing system can be expansible by utilization of other organic material, so it is supported the efficient operation.
文摘In rural area of sub-Saharan Africa, the electrification rate is only 23%. There are isolated diesel power stations in sub-Saharan countries. However, power production by diesel generator is relatively high compared to that of national grid. In addition, public facilities such as rural school and health clinic have important role inproviding adequate public services in non-electrified communities. Therefore, in order to reduce power production cost, optimum configuration of the wind diesel hybrid generation system and the economic feasibility were studied. In the study, operational data of the existing diesel generator and wind potential were analyzed and optimum configuration of wind and diesel hybrid system was proposed. In addition, economic feasibility study of the hybrid system was conducted. In the result, EIRR (economic internal rate of return) of the proposed wind-diesel hybrid power plant was obtained as 10%.
基金supported by the Jiangsu Provincial Natural Science Foundation of China(No.BK-2010612)the Foundation of State Key Laboratory of Soil and Sustainable Agriculture,China(No.Y05-2010034)the National Natural Science Foundation of China(No.41001147)
文摘The rice-wheat rotation in southern China is characterized by frequent flooding-draining water regime and heavy nitrogen(N)fertilization. There is a substantial lack of studies into the behavior of dissolved organic nitrogen(DON) in the intensively managed agroecosystem. A 3-year in situ field experiment was conducted to determine DON leaching and its seasonal and yearly variations as affected by fertilization, irrigation and precipitation over 6 consecutive rice/wheat seasons. Under the conventional N practice(300kg N ha-1for rice and 200 kg N ha-1for wheat), the seasonal average DON concentrations in leachate(100 cm soil depth) for the three rice and wheat seasons were 0.6–1.1 and 0.1–2.3 mg N L-1, respectively. The cumulative DON leaching was estimated to be1.1–2.3 kg N ha-1for the rice seasons and 0.01–1.3 kg N ha-1for the wheat seasons, with an annual total of 1.1–3.6 kg N ha-1. In the rice seasons, N fertilizer had little effect(P > 0.05) on DON leaching; precipitation and irrigation imported 3.6–9.1 kg N ha-1of DON, which may thus conceal the fertilization effect on DON. In the wheat seasons, N fertilization had a positive effect(P < 0.01)on DON. Nevertheless, this promotive effect was strongly influenced by variable precipitation, which also carried 1.8–2.9 kg N ha-1of DON into fields. Despite a very small proportion to chemical N applied and large variations driven by water regime, DON leaching is necessarily involved in the integrated field N budget in the rice-wheat rotation due to its relatively greater amount compared to other natural ecosystems.