Excessive nitrogen（N） fertilization in intensive agricultural areas such as the plain region of South China has resulted in low nitrogen use efficiency and serious environmental problems. To determine the optimum N ...Excessive nitrogen（N） fertilization in intensive agricultural areas such as the plain region of South China has resulted in low nitrogen use efficiency and serious environmental problems. To determine the optimum N application rate, grain yield, apparent nitrogen recovery efficiency（ANRE）, apparent N loss, and ammonium（NH_3） volatilization under different N application rates in the three years from 2012 to 2014 were studied. The results showed that the relationship between grain yields and N application rate in the three years were well fitted by quadratic equations. When N application rate reached 197 kg ha^（–1） in 2012, 199 kg ha^（–1） in 2013 and 196 kg ha^（–1） in 2014, the plateau of the grain yields appeared. With the increase of N application rate, the ANRE for rice decreased which could be expressed with sigmoidal equation; when N application rate was 305 kg ha^（–1） in 2012, 275 kg ha^（–1） in 2013 and 312 kg ha^（–1） in 2014, the curves of ANRE appeared turing points. Besides, the relationship between soil Nresidual and N application rate was fitted by the quadratic equation and the maximums of soil Nresidual were reached in the three years with the N application rate of 206, 244 and 170 kg ha^（–1）, respectively. Statistical analysis indicated that NH3 volatilization and apparent N loss in three years all increased with the increasing N application rate. When the amount of NH3 volatilization increased to 11.6 kg N ha^（–1） in 2012, 40.5 kg N ha^（–1） in 2013 and 57.0 kg N ha^（–1）in 2014, the apparent N loss in the three years had obvious increase. To determine the optimum N application rate, the average N application on the plateau of the grain yield was considered as the lower limit while the average N application rate at the turning points of ANRE, the residual N in soil and apparent N loss was taken as the upper limit. According to the results in three years, the optimum N application rate for rice in Zhejiang was 197–255 kg ha^（–1）.展开更多
[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer ...[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer peanuts.[Methods]Four treatments were set up in the experiment:no-nitrogen plot(N 0P_(4)K_(4)),optimized nitrogen plot(N_(7)P_(4)K_(4)),70%optimized nitrogen plot(N_(5)P_(4)K_(4)),130%optimized nitrogen plot(N 9P 4K 4),repeated 3 times,and arranged in random blocks.The area of the plot was 42 m^(2),ridges were set between the plots,and protective rows of more than 1 m were set around the experimental site.The types of fertilizers were urea,superphosphate,and imported potassium chloride,and the variety of peanuts was Linhua 5.Except for the level of fertilization,other agricultural operations were the same,and soil sampling tests,field records,and yield testing were carried out according to the requirements of the plan.[Results]On the basis of 60 kg/ha of phosphorus and potassium fertilizer application,the optimum economical fertilizer application rate and the highest application rate of pure nitrogen were about 115.20 and 131.25 kg/ha,respectively.[Conclusions]This study is expected to provide a certain basis for the high-quality and high-yield summer peanuts in southern Shandong area.展开更多
A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All trav...A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All travelers were divided into two classes. The first guided travelers were referred to as the equipped travelers who follow ATIS advice, while the second unguided travelers were referred to as the unequipped travelers and the equipped travelers who do not follow the ATIS advice(also referred to as non-complied travelers). Travelers were assumed to take travel time, congestion pricing, and travel time reliability into account when making travel route choice decisions. In order to arrive at on time, travelers needed to allow for a safety margin to their trip.The market penetration of ATIS was determined by a continuous increasing function of the information benefit, and the ATIS compliance rate of equipped travelers was given as the probability of the actually experienced travel costs of guided travelers less than or equal to those of unguided travelers. The analysis results could enhance our understanding of the effect of travel demand level and travel time reliability confidence level on the ATIS market penetration and compliance rate; and the effect of travel time perception variation of guided and unguided travelers on the mean travel cost savings(MTCS) of the equipped travelers, the ATIS market penetration, compliance rate, and the total network effective travel time(TNETT).展开更多
基金supported by the National Natural Science Foundation of China(41501238)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2015BAD23B03)the Special Fund for Agro-scientific Research in the Public Interest from the Ministry of Agriculture,China(201003014-02-08)
文摘Excessive nitrogen（N） fertilization in intensive agricultural areas such as the plain region of South China has resulted in low nitrogen use efficiency and serious environmental problems. To determine the optimum N application rate, grain yield, apparent nitrogen recovery efficiency（ANRE）, apparent N loss, and ammonium（NH_3） volatilization under different N application rates in the three years from 2012 to 2014 were studied. The results showed that the relationship between grain yields and N application rate in the three years were well fitted by quadratic equations. When N application rate reached 197 kg ha^（–1） in 2012, 199 kg ha^（–1） in 2013 and 196 kg ha^（–1） in 2014, the plateau of the grain yields appeared. With the increase of N application rate, the ANRE for rice decreased which could be expressed with sigmoidal equation; when N application rate was 305 kg ha^（–1） in 2012, 275 kg ha^（–1） in 2013 and 312 kg ha^（–1） in 2014, the curves of ANRE appeared turing points. Besides, the relationship between soil Nresidual and N application rate was fitted by the quadratic equation and the maximums of soil Nresidual were reached in the three years with the N application rate of 206, 244 and 170 kg ha^（–1）, respectively. Statistical analysis indicated that NH3 volatilization and apparent N loss in three years all increased with the increasing N application rate. When the amount of NH3 volatilization increased to 11.6 kg N ha^（–1） in 2012, 40.5 kg N ha^（–1） in 2013 and 57.0 kg N ha^（–1）in 2014, the apparent N loss in the three years had obvious increase. To determine the optimum N application rate, the average N application on the plateau of the grain yield was considered as the lower limit while the average N application rate at the turning points of ANRE, the residual N in soil and apparent N loss was taken as the upper limit. According to the results in three years, the optimum N application rate for rice in Zhejiang was 197–255 kg ha^（–1）.
基金Supported by the Project of Peanut Innovation Team of Shandong Province Modern Agricultural Industry Technology System(SDAIT-05-022).
文摘[Objectives]To study the effect of nitrogen(N)on the growth demand of summer peanuts under a certain level of phosphorus and potassium fertilizers,and to carry out experiments on nitrogen fertilizer control of summer peanuts.[Methods]Four treatments were set up in the experiment:no-nitrogen plot(N 0P_(4)K_(4)),optimized nitrogen plot(N_(7)P_(4)K_(4)),70%optimized nitrogen plot(N_(5)P_(4)K_(4)),130%optimized nitrogen plot(N 9P 4K 4),repeated 3 times,and arranged in random blocks.The area of the plot was 42 m^(2),ridges were set between the plots,and protective rows of more than 1 m were set around the experimental site.The types of fertilizers were urea,superphosphate,and imported potassium chloride,and the variety of peanuts was Linhua 5.Except for the level of fertilization,other agricultural operations were the same,and soil sampling tests,field records,and yield testing were carried out according to the requirements of the plan.[Results]On the basis of 60 kg/ha of phosphorus and potassium fertilizer application,the optimum economical fertilizer application rate and the highest application rate of pure nitrogen were about 115.20 and 131.25 kg/ha,respectively.[Conclusions]This study is expected to provide a certain basis for the high-quality and high-yield summer peanuts in southern Shandong area.
基金Project(12YJCZH309) supported by Humanities and Social Sciences Youth Foundation of the Ministry of Education of ChinaProject(20120041120006) supported by Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘A reliability-based stochastic system optimum congestion pricing(SSOCP) model with endogenous market penetration and compliance rate in an advanced traveler information systems(ATIS) environment was proposed. All travelers were divided into two classes. The first guided travelers were referred to as the equipped travelers who follow ATIS advice, while the second unguided travelers were referred to as the unequipped travelers and the equipped travelers who do not follow the ATIS advice(also referred to as non-complied travelers). Travelers were assumed to take travel time, congestion pricing, and travel time reliability into account when making travel route choice decisions. In order to arrive at on time, travelers needed to allow for a safety margin to their trip.The market penetration of ATIS was determined by a continuous increasing function of the information benefit, and the ATIS compliance rate of equipped travelers was given as the probability of the actually experienced travel costs of guided travelers less than or equal to those of unguided travelers. The analysis results could enhance our understanding of the effect of travel demand level and travel time reliability confidence level on the ATIS market penetration and compliance rate; and the effect of travel time perception variation of guided and unguided travelers on the mean travel cost savings(MTCS) of the equipped travelers, the ATIS market penetration, compliance rate, and the total network effective travel time(TNETT).
