为加强农产品质量安全管理,保证消费者身体健康,从农产品供应链的角度出发,提出基于农产品供应链的质量安全可追溯系统的设计方案。在危害分析和关键控制点(hazard analysis and critical control point,HACCP)管理体系的指导下,利用二...为加强农产品质量安全管理,保证消费者身体健康,从农产品供应链的角度出发,提出基于农产品供应链的质量安全可追溯系统的设计方案。在危害分析和关键控制点(hazard analysis and critical control point,HACCP)管理体系的指导下,利用二维码技术、数据库技术、网络信息技术进行系统的构建和开发,实现了农产品在整个供应链上从种植、采收、加工到销售的全程跟踪和溯源,有效地加强了对农产品质量安全的监管,保证消费者最终知情权。目前,该系统在江苏江阴地区实际测试效果良好,验证了方案的可行性和有效性。展开更多
High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however,the N budgets of such intensive vegetable production remain to be explored.The goal...High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however,the N budgets of such intensive vegetable production remain to be explored.The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato,cucumber,and celery at five N (urea) application rates (0,348,522,696,and 870 kg N ha-1 year-1).Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha-1,and N fertilizer was the main N source,accounting for 66%-83% of the total annual N input.In comparison,irrigation water,wet deposition,and seeds in total accounted for less than 1% of the total N input.The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha-1 and decreased as the application rate increased from 522 to 870 kg N ha-1.Apparent N losses were 196-201 kg N ha-1,of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha-1.Thus,leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season.Moreover,dissolved organic N accounted for 10% of the leached N,whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system.展开更多
文摘为加强农产品质量安全管理,保证消费者身体健康,从农产品供应链的角度出发,提出基于农产品供应链的质量安全可追溯系统的设计方案。在危害分析和关键控制点(hazard analysis and critical control point,HACCP)管理体系的指导下,利用二维码技术、数据库技术、网络信息技术进行系统的构建和开发,实现了农产品在整个供应链上从种植、采收、加工到销售的全程跟踪和溯源,有效地加强了对农产品质量安全的监管,保证消费者最终知情权。目前,该系统在江苏江阴地区实际测试效果良好,验证了方案的可行性和有效性。
基金Supported by the National Natural Science Foundation of China-Japan Science and Technology Agency (NSFC-JST)Major International Joint Research Project (No. 30821140542)+1 种基金the National Basic Research Program (973 Program) of China (No. 2007CB109303)the Major Science and Technology Program for Water Pollution Control and Treatment of China (No. 2008ZX07101-005)
文摘High rates of fertilizer nitrogen (N) are applied in greenhouse vegetable fields in southeastern China to maximize production;however,the N budgets of such intensive vegetable production remain to be explored.The goal of this study was to determine the annual N balance and loss in a greenhouse vegetable system of annual rotation of tomato,cucumber,and celery at five N (urea) application rates (0,348,522,696,and 870 kg N ha-1 year-1).Total N input to the 0-50 cm soil layer ranged from 531 to 1 053 kg ha-1,and N fertilizer was the main N source,accounting for 66%-83% of the total annual N input.In comparison,irrigation water,wet deposition,and seeds in total accounted for less than 1% of the total N input.The fertilizer N use efficiency was only 18% under the conventional application rate of 870 kg N ha-1 and decreased as the application rate increased from 522 to 870 kg N ha-1.Apparent N losses were 196-201 kg N ha-1,of which 71%-86% was lost by leaching at the application rates of 522-870 kg N ha-1.Thus,leaching was the primary N loss pathway at high N application rates and the amount of N leached was proportional to the N applied during the cucumber season.Moreover,dissolved organic N accounted for 10% of the leached N,whereas NH3 volatilization only contributed 0.1%-0.6% of the apparent N losses under the five N application rates in this greenhouse vegetable system.
