Improving the soil and biomass with coal is estimated at the international level as a way to enhance soil productiveness, fertility and also to mitigate climate change. Biochar employed to improve land scope and impou...Improving the soil and biomass with coal is estimated at the international level as a way to enhance soil productiveness, fertility and also to mitigate climate change. Biochar employed to improve land scope and impound carbon, is attracting a great deal of attention. Its characteristics of chemical, physical and biological properties, containing big surface area, CEC (Cation Exchange Capacity), high water-holding capacity, size of pore, volume, distribution, and element composition, affect its recognized influences, particularly on microbial communities. These are discovered in the agriculture lands, lands remediation and composting. However, incomplete information existed about biochar for several farmers or peasants in agriculture scope. Therefore, farmers or peasants and gardeners are facing new opportunities and defiance each day, from feeding global extending and expanding population, whilst meeting severe new emissions requirements, to create more food on fewer land area while reducing their environmental emissions. Widespread application and utilization of biochar in agricultural scope, forestry production, energy, environmental protection and additional areas, has interested awareness by scientists and investigators inside and/or outside the country. The objective of this paper is to provide a guide for the farmers or peasants and gardeners with an essential information about biochar and what the ability of biochar can be achieved in the soil, and which can provide the scientific reference for the biochar application, and to get high yield and good quality of crops in all of different soils.展开更多
Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degra...Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degradation of soil, drip irrigation system as well plants. This study assessed the damages on the drip irrigation system and soil, inflicted by the use of low-quality irrigation water. The quality of water was improved with reference to raw water in terms of pH (1.57% - 5.88%), EC (3.08% - 10.08%), ions (0.96% - 46%) by using magnetization method, without disrupting the existing irrigation system in the basaltic aquifer in semi-arid to the arid condition. This was demonstrated before the farmers in central India.展开更多
This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides ...This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides (vegetable farmers). The social survey method was used to conduct this study;100 vegetable farmers were selected randomly. The data collected through questionnaires, observation, and interviews for primary data, previous</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> concerned, and reference documents were used to collect secondary data. Data collected were analyzed using the statistical packages for social science (SPSS). The study yielded some useful results, the most important of which are: the presence of respondents who obtain their information about pesticides from merchants, the absence of a guide provider in their area, and the absence of any seminars or lectures on the use of pesticides, or programs. For</span><span style="font-family:""> </span><span style="font-family:Verdana;">example, radio and television programs were presented but protective clothing was not used. This study is based on the researcher's advocate for the following: intensifying agricultural extension and employee visits to the agricultural field, in addition to intensifying educational evidence for consumers regarding pesticides and providing preliminary data on pesticides and how to deal with them and increase them. Educat</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> farmers about the safe use of pesticides and identify the risks and damages that pesticides cause to humans</span><span style="font-family:Verdana;">.展开更多
Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result...Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result of natural hydrological change. It is more severe when water acts as a backbone in economic policies, planning and management methods. Water scarcity can be expected to increase with most forms of economic development, but, if properly identified, many of its causes can be expected and avoided or mitigated. However, the limited irrigation management is considered a very important issue in the agricultural scope. Therefore, in this study</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the relationship between water, crop production, photosynthesis, crop transpiration, crop growth, crop yields and water use efficiency have been discussed under limited irrigation conditions. However, the crops have some ability to adapt and resist against limited irrigation. Hence, under high temperate conditions, this is a shortage of water and photosynthesis is decreased with a pore (stoma) restraining. At the same time</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the evapotranspiration reaches to the utmost value and the water use efficiency rises because of optimal monitoring of leaf pore (stoma). Therefore, the modality which is the reduction of the risks and improving industrial control in incomplete irrigation are the chief constraints of providing irrigation water in the future, which leads to increased crop production and ultimately providing a provision of food security.展开更多
Many regions around the world are characterized by limited water resources, where the average annual per capita renewable water is about 1000 -1700 cubic meters. For instance, in china the problems of water supply are...Many regions around the world are characterized by limited water resources, where the average annual per capita renewable water is about 1000 -1700 cubic meters. For instance, in china the problems of water supply are widely known globally. Though, China is facing main problem which is how to distribute water, instead of water shortage in itself. Therefore, restricted resources of water are increasingly stressed in the future by many factors such as excessive clouds of water, pollution and climate change. On the other hand, most studies have been indicated that the agricultural sector is one of the sectors that will face a large water deficit in the future due to the high demand for food, competition for water resources, drought and the high consumption of water due to the acquisition of traditional surface irrigation techniques. In spite of introduce modern irrigation methods such as drip irrigation in agriculture by developing irrigation methods and eliminating old traditional irrigation methods, however, its efficiency is related to the qualifying of farms and users of irrigation water, where they are the main users of irrigation water in water resources management. The considerable challenge facing agriculture is to raise irrigation efficiency depending on water-saving irrigation systems to provide water resources for crops. Therefore, the purpose of this study was to provide farmers with important points about using drip irrigation technology, to raise their technical level in using irrigation water, through their guidance to the best techniques and to avoid some common mistakes in design, utilization, management and maintenance of drip irrigation system.展开更多
The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surroundi...The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surrounding fresh water aquifers. In this study, a water quality index (WQI), indicating the water quality has been adopted. The WQI was determined on a basis of various physico-chemical parameters like pH, conductivity, turbidity, dissolved oxygen, calcium, magnesium, chloride, nitrates, ammonium and sodium. The index was used both for tracking changes at one site over time, and for comparisons among sites. The WQI was also employed to wells used for irrigation on farms along the Keta Sand Spit as well as that of the Keta Lagoon Complex and its surrounding floodplains, in order to ascertain the quality of water for public and livestock consumption, irrigation, recreation and other purposes. The WQI of the wells, Keta lagoon and its floodplains showed various degrees of poor water quality and therefore considered unsuitable for drinking and recreation. By WHO standards, this calls for intensive physical and chemical treatment of the water for human consumption.展开更多
Vertical cultivation is the most important method in the future spatially in smart agriculture systems. The fourth different thickness soilless textile was used as the board to cultivate water-cress (Eruca Sativa). Th...Vertical cultivation is the most important method in the future spatially in smart agriculture systems. The fourth different thickness soilless textile was used as the board to cultivate water-cress (Eruca Sativa). The vacuum pump model VRI V3 Dual Stage Vacuum Pump was constructed and used in the preliminary experimental test. It’s run to measure the water content and water absorption percentage for soilless board under lab conditions. Different tests were evaluated for the absorption sample after elapsed time 0.08, 0.17, 0.25, 5, 24 and 120 hours. Soilless board textile with thickness 32 mm, 26 mm, 21 mm and 16 mm made from the following material: woven fabric of Cotton. The four mattresses of smart textile as soilless vertical cultivation, measuring 40 cm width 60 cm length were created;it has filler from soft sawdust, a mixture of red (beech) and white (Swedish) wood. The result of preliminary test illustrated that the soilless board may be able to keep the amount of water for more than 72.3% after 5 days from edit water to soilless board. The soilless smart with 32 mm thickness gave highly growths of water-cress compared with the other smart mattress.展开更多
Proportional integral plus feedforward (PI+FF) control was proposed for identifying the pipe temperature in hot water heating greenhouse. To get satisfying control result, ten coefficients must be adjusted properly. T...Proportional integral plus feedforward (PI+FF) control was proposed for identifying the pipe temperature in hot water heating greenhouse. To get satisfying control result, ten coefficients must be adjusted properly. The data for training and testing the radial basic function (RBF) neural-networks model of greenhouse were collected in a 1028 m2 multi-span glasshouse. Based on this model, a method of coefficients adjustment is described in this article.展开更多
A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the d...A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.展开更多
Environmental impact and economic concerns have driven a variable rate technology(VRT).Spinner spreaders were mainly used for granular fertilizer application since they are simple in design,inexpensive,and can cover l...Environmental impact and economic concerns have driven a variable rate technology(VRT).Spinner spreaders were mainly used for granular fertilizer application since they are simple in design,inexpensive,and can cover large areas.However,the spreader was not adequate for VRT because uniformity changes drastically while varying application rates.Thus,the purpose of this study was to develop a variable rate applicator with uniform spreading patterns.A commercial spreader was modified with a controller and electric actuators for controlling fertilizer discharge directions and amounts.Database was established to determine the optimum discharge direction according to the fertilizer application amount.The uniformity of spreading patterns in accordance with the spread amount per set unit area was evaluated by the statistical coefficient of variation(CV)lower than 15%is assumed to prevent damage to the crop.Test results showed that CVs were 8%,9%,and 8%,respectively,for a tractor in race track mode(adjacent passes in same direction of travel)at 200 kg/hm^(2),300 kg/hm^(2),and 400 kg/hm^(2).This indicates that the fertilizer was spread uniformly,while the coefficient of variation was 12%at 200 kg/hm^(2) in back and forth mode(adjacent passes in the opposite direction of travel).Overall,the results suggest that the race track mode is suitable for operation of a tractor to ensure uniform spreading of fertilizer when applying at variable rates.The future goal is to establish a system for automatic variable rate application according to location in connection with soil analysis and geographic information systems.展开更多
The moisture-dependent physical properties are important in designing and fabricating equipment and structures for handling,transporting,processing and storage,and also for assessing quality.This study was carried out...The moisture-dependent physical properties are important in designing and fabricating equipment and structures for handling,transporting,processing and storage,and also for assessing quality.This study was carried out to determine the effect of moisture content on some physical and mechanical properties for two varieties of chickpea seeds(Giza 3,and Giza 195).Four levels of moisture content ranging from 11.6%d.b.(dry basis)to 25.4%d.b.were used.The average length,width,thickness,and geometric mean diameter ranged from(7.92±0.04)mm to(8.14±0.04)mm,(6.10±0.04)mm to(6.37±0.04)mm,(6.43±0.04)mm to(6.84±0.04)mm and(6.77±0.07)mm to(7.08±0.07)mm,respectively.The average sphericity and roundness ranged from(85.53±0.19)%to(87.00±0.19)%and(93.70±0.35)%to(94.14±0.35)%,respectively.The average measured surface area,calculated surface area,and projected area ranged from(144.73±1.55)mm2 to(158.78±1.55)mm2,(146.89±1.58)mm2 to(159.78±1.58)mm2,and(46.53±0.50)mm2 to(48.93±0.50)mm2,respectively.The average bulk density,true density,porosity and angle of repose ranged from(730.05±11.84)kg/m3 to(694.17±11.84)kg/m3,(1,225.12±19.51)kg/m3 to(1,308.02±19.51)kg/m3,(44.13±0.49)%to(43.29±0.49)%,and(25.20±0.41)o(degrees)to(29.10±0.41)o(degrees),respectively and also increased linearly with an increase in moisture content.The average seed weight and thousand seeds weight ranged from(0.142±0.002)gm to(0.184±0.002)gm,and(177.38±2.17)gm to(194.75±2.17)gm,respectively.The average static coefficient of friction against wood,stainless steel,galvanized iron and iron surfaces and internal with the same seeds ranged from(0.430±0.016)to(0.460±0.016),(0.321±0.007)to(0.366±0.007),(0.327±0.004)to(0.371±0.004),(0.412±0.011)to(0.496±0.011)and(0.638±0.022)to(0.741±0.022),respectively.The average terminal velocity ranged from(5.18±0.34)m/s to(9.14±0.34)m/s.The average penetration depth at load 6kg and tools diameter 1 mm was determined as mechanical property,and generally increased in magnitude with an increase in moisture content.The physical properties were linearly dependent upon moisture content.展开更多
文摘Improving the soil and biomass with coal is estimated at the international level as a way to enhance soil productiveness, fertility and also to mitigate climate change. Biochar employed to improve land scope and impound carbon, is attracting a great deal of attention. Its characteristics of chemical, physical and biological properties, containing big surface area, CEC (Cation Exchange Capacity), high water-holding capacity, size of pore, volume, distribution, and element composition, affect its recognized influences, particularly on microbial communities. These are discovered in the agriculture lands, lands remediation and composting. However, incomplete information existed about biochar for several farmers or peasants in agriculture scope. Therefore, farmers or peasants and gardeners are facing new opportunities and defiance each day, from feeding global extending and expanding population, whilst meeting severe new emissions requirements, to create more food on fewer land area while reducing their environmental emissions. Widespread application and utilization of biochar in agricultural scope, forestry production, energy, environmental protection and additional areas, has interested awareness by scientists and investigators inside and/or outside the country. The objective of this paper is to provide a guide for the farmers or peasants and gardeners with an essential information about biochar and what the ability of biochar can be achieved in the soil, and which can provide the scientific reference for the biochar application, and to get high yield and good quality of crops in all of different soils.
文摘Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degradation of soil, drip irrigation system as well plants. This study assessed the damages on the drip irrigation system and soil, inflicted by the use of low-quality irrigation water. The quality of water was improved with reference to raw water in terms of pH (1.57% - 5.88%), EC (3.08% - 10.08%), ions (0.96% - 46%) by using magnetization method, without disrupting the existing irrigation system in the basaltic aquifer in semi-arid to the arid condition. This was demonstrated before the farmers in central India.
文摘This study was carried out in the northern Khartoum (Bahry Locality) with the aim of knowing the role of agricultural extension in developing the awareness of the farmer to the danger of residual effect of pesticides (vegetable farmers). The social survey method was used to conduct this study;100 vegetable farmers were selected randomly. The data collected through questionnaires, observation, and interviews for primary data, previous</span><span style="font-family:Verdana;">ly</span><span style="font-family:Verdana;"> concerned, and reference documents were used to collect secondary data. Data collected were analyzed using the statistical packages for social science (SPSS). The study yielded some useful results, the most important of which are: the presence of respondents who obtain their information about pesticides from merchants, the absence of a guide provider in their area, and the absence of any seminars or lectures on the use of pesticides, or programs. For</span><span style="font-family:""> </span><span style="font-family:Verdana;">example, radio and television programs were presented but protective clothing was not used. This study is based on the researcher's advocate for the following: intensifying agricultural extension and employee visits to the agricultural field, in addition to intensifying educational evidence for consumers regarding pesticides and providing preliminary data on pesticides and how to deal with them and increase them. Educat</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> farmers about the safe use of pesticides and identify the risks and damages that pesticides cause to humans</span><span style="font-family:Verdana;">.
文摘Water scarcity is relative and variable concept that can occur at any level of supply and demand. It is also a social construct, which is linked to the intervention in the water cycle and changes over time as a result of natural hydrological change. It is more severe when water acts as a backbone in economic policies, planning and management methods. Water scarcity can be expected to increase with most forms of economic development, but, if properly identified, many of its causes can be expected and avoided or mitigated. However, the limited irrigation management is considered a very important issue in the agricultural scope. Therefore, in this study</span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the relationship between water, crop production, photosynthesis, crop transpiration, crop growth, crop yields and water use efficiency have been discussed under limited irrigation conditions. However, the crops have some ability to adapt and resist against limited irrigation. Hence, under high temperate conditions, this is a shortage of water and photosynthesis is decreased with a pore (stoma) restraining. At the same time</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> the evapotranspiration reaches to the utmost value and the water use efficiency rises because of optimal monitoring of leaf pore (stoma). Therefore, the modality which is the reduction of the risks and improving industrial control in incomplete irrigation are the chief constraints of providing irrigation water in the future, which leads to increased crop production and ultimately providing a provision of food security.
文摘Many regions around the world are characterized by limited water resources, where the average annual per capita renewable water is about 1000 -1700 cubic meters. For instance, in china the problems of water supply are widely known globally. Though, China is facing main problem which is how to distribute water, instead of water shortage in itself. Therefore, restricted resources of water are increasingly stressed in the future by many factors such as excessive clouds of water, pollution and climate change. On the other hand, most studies have been indicated that the agricultural sector is one of the sectors that will face a large water deficit in the future due to the high demand for food, competition for water resources, drought and the high consumption of water due to the acquisition of traditional surface irrigation techniques. In spite of introduce modern irrigation methods such as drip irrigation in agriculture by developing irrigation methods and eliminating old traditional irrigation methods, however, its efficiency is related to the qualifying of farms and users of irrigation water, where they are the main users of irrigation water in water resources management. The considerable challenge facing agriculture is to raise irrigation efficiency depending on water-saving irrigation systems to provide water resources for crops. Therefore, the purpose of this study was to provide farmers with important points about using drip irrigation technology, to raise their technical level in using irrigation water, through their guidance to the best techniques and to avoid some common mistakes in design, utilization, management and maintenance of drip irrigation system.
文摘The Keta Lagoon and its catchment areas in Ghana are influenced by intensive agriculture and the use of agro-chemicals. It has therefore, become necessary to assess the quality of water in the lagoon and the surrounding fresh water aquifers. In this study, a water quality index (WQI), indicating the water quality has been adopted. The WQI was determined on a basis of various physico-chemical parameters like pH, conductivity, turbidity, dissolved oxygen, calcium, magnesium, chloride, nitrates, ammonium and sodium. The index was used both for tracking changes at one site over time, and for comparisons among sites. The WQI was also employed to wells used for irrigation on farms along the Keta Sand Spit as well as that of the Keta Lagoon Complex and its surrounding floodplains, in order to ascertain the quality of water for public and livestock consumption, irrigation, recreation and other purposes. The WQI of the wells, Keta lagoon and its floodplains showed various degrees of poor water quality and therefore considered unsuitable for drinking and recreation. By WHO standards, this calls for intensive physical and chemical treatment of the water for human consumption.
文摘Vertical cultivation is the most important method in the future spatially in smart agriculture systems. The fourth different thickness soilless textile was used as the board to cultivate water-cress (Eruca Sativa). The vacuum pump model VRI V3 Dual Stage Vacuum Pump was constructed and used in the preliminary experimental test. It’s run to measure the water content and water absorption percentage for soilless board under lab conditions. Different tests were evaluated for the absorption sample after elapsed time 0.08, 0.17, 0.25, 5, 24 and 120 hours. Soilless board textile with thickness 32 mm, 26 mm, 21 mm and 16 mm made from the following material: woven fabric of Cotton. The four mattresses of smart textile as soilless vertical cultivation, measuring 40 cm width 60 cm length were created;it has filler from soft sawdust, a mixture of red (beech) and white (Swedish) wood. The result of preliminary test illustrated that the soilless board may be able to keep the amount of water for more than 72.3% after 5 days from edit water to soilless board. The soilless smart with 32 mm thickness gave highly growths of water-cress compared with the other smart mattress.
基金Project (No. 2002C12021) supported by the Science and Technology Department of Zhejiang Province,China
文摘Proportional integral plus feedforward (PI+FF) control was proposed for identifying the pipe temperature in hot water heating greenhouse. To get satisfying control result, ten coefficients must be adjusted properly. The data for training and testing the radial basic function (RBF) neural-networks model of greenhouse were collected in a 1028 m2 multi-span glasshouse. Based on this model, a method of coefficients adjustment is described in this article.
文摘A solar drum dryer was designed and constructed for paddy drying,including a fixed outer drum and inner perforated drum,which rotated at the desired rotational speed inside the outer drum.The maximum capacity of the dryer was 10000 g.The rotational speed of the inner drum was controlled.The thermal energy required for the dryer was provided by a solar absorber plate.The dryer per-formance was examined at three levels of rotational speed(0.21,0.42 and 0.84 r.p.m.),drum slope(1°,1.5°and 2°)and air velocity(1.7,1.8 and 1.9 m.s^(-1)).The diameter of the drum was the geometrical parameter that affected the movement of the particles and the ratio of the particle diameter to the drum diameter changed with the change in the drum diameter.Therefore,increasing the diameter of the drum caused a reduction in the repose angle of the paddy without any effect on the filling angle.The displacement of the product along the drum increased with increasing slope and rotational speed.At the lowest air velocity,the time required to remove moisture(<13%)was less.The results showed a significant reduction in cracked brown rice for the paddy dried by the drum dryer at 43-46℃ compared with those dried using a batch dryer.The highest stress-cracking index(11)was observed for the paddy with an initial moisture of 16%.The results showed that for proportional final moisture content,a longer drum should be considered to intensify the slope and rotational speed of the inner drum.
基金This work was carried out with the support of the“Cooperative Research Program for Agriculture Science&Technology Development”(Project No.PJ01050303),Rural Development Administration,Republic of Korea.
文摘Environmental impact and economic concerns have driven a variable rate technology(VRT).Spinner spreaders were mainly used for granular fertilizer application since they are simple in design,inexpensive,and can cover large areas.However,the spreader was not adequate for VRT because uniformity changes drastically while varying application rates.Thus,the purpose of this study was to develop a variable rate applicator with uniform spreading patterns.A commercial spreader was modified with a controller and electric actuators for controlling fertilizer discharge directions and amounts.Database was established to determine the optimum discharge direction according to the fertilizer application amount.The uniformity of spreading patterns in accordance with the spread amount per set unit area was evaluated by the statistical coefficient of variation(CV)lower than 15%is assumed to prevent damage to the crop.Test results showed that CVs were 8%,9%,and 8%,respectively,for a tractor in race track mode(adjacent passes in same direction of travel)at 200 kg/hm^(2),300 kg/hm^(2),and 400 kg/hm^(2).This indicates that the fertilizer was spread uniformly,while the coefficient of variation was 12%at 200 kg/hm^(2) in back and forth mode(adjacent passes in the opposite direction of travel).Overall,the results suggest that the race track mode is suitable for operation of a tractor to ensure uniform spreading of fertilizer when applying at variable rates.The future goal is to establish a system for automatic variable rate application according to location in connection with soil analysis and geographic information systems.
文摘The moisture-dependent physical properties are important in designing and fabricating equipment and structures for handling,transporting,processing and storage,and also for assessing quality.This study was carried out to determine the effect of moisture content on some physical and mechanical properties for two varieties of chickpea seeds(Giza 3,and Giza 195).Four levels of moisture content ranging from 11.6%d.b.(dry basis)to 25.4%d.b.were used.The average length,width,thickness,and geometric mean diameter ranged from(7.92±0.04)mm to(8.14±0.04)mm,(6.10±0.04)mm to(6.37±0.04)mm,(6.43±0.04)mm to(6.84±0.04)mm and(6.77±0.07)mm to(7.08±0.07)mm,respectively.The average sphericity and roundness ranged from(85.53±0.19)%to(87.00±0.19)%and(93.70±0.35)%to(94.14±0.35)%,respectively.The average measured surface area,calculated surface area,and projected area ranged from(144.73±1.55)mm2 to(158.78±1.55)mm2,(146.89±1.58)mm2 to(159.78±1.58)mm2,and(46.53±0.50)mm2 to(48.93±0.50)mm2,respectively.The average bulk density,true density,porosity and angle of repose ranged from(730.05±11.84)kg/m3 to(694.17±11.84)kg/m3,(1,225.12±19.51)kg/m3 to(1,308.02±19.51)kg/m3,(44.13±0.49)%to(43.29±0.49)%,and(25.20±0.41)o(degrees)to(29.10±0.41)o(degrees),respectively and also increased linearly with an increase in moisture content.The average seed weight and thousand seeds weight ranged from(0.142±0.002)gm to(0.184±0.002)gm,and(177.38±2.17)gm to(194.75±2.17)gm,respectively.The average static coefficient of friction against wood,stainless steel,galvanized iron and iron surfaces and internal with the same seeds ranged from(0.430±0.016)to(0.460±0.016),(0.321±0.007)to(0.366±0.007),(0.327±0.004)to(0.371±0.004),(0.412±0.011)to(0.496±0.011)and(0.638±0.022)to(0.741±0.022),respectively.The average terminal velocity ranged from(5.18±0.34)m/s to(9.14±0.34)m/s.The average penetration depth at load 6kg and tools diameter 1 mm was determined as mechanical property,and generally increased in magnitude with an increase in moisture content.The physical properties were linearly dependent upon moisture content.