In northwestern China, there has been a change from traditional cultivation system （TC） with no mulching and flood irrigation to a more modern cultivation system （MC） using plastic film mulching with drip irrigati...In northwestern China, there has been a change from traditional cultivation system （TC） with no mulching and flood irrigation to a more modern cultivation system （MC） using plastic film mulching with drip irrigation. A field study was conducted to compare soil ＇C02 concentrations and soil surface COs fluxes between TC and MC systems during a cotton growing season. CO2 concentrations in the soil profile were higher in the MC system （3107-9212μL L-1） than in the TC system （1 275-8994 μL L-1） but the rate of CO2 flux was lower in the MC system. Possible reasons for this included decreased gas diffusion and higher soil moisture due to the mulching cover in the MC system, and the consumption of soil CO2 by weathering reactions. Over the whole cotton growing season, accumulated rates of CO2 flux were 300 and 394 g C m-2 for the MC and TC systems, respectively. When agricultural practices were converted from traditional cultivation to a plastic film mulching system, soil CO2 emissions could be reduced by approximately 100 g C m-2 year-1 in agricultural lands in arid and/or semi-arid areas of northern and northwestern China.展开更多
为解决农业大棚种植环境监测的近距离、高成本、低精度问题,设计并实现一种太阳能供电的农业大棚环境监测系统.以STM32F103C8T6单片机作为主控芯片,传感器采集大棚的CO2、温度、湿度参数,采用射频技术和通用分组无线服务(general packet...为解决农业大棚种植环境监测的近距离、高成本、低精度问题,设计并实现一种太阳能供电的农业大棚环境监测系统.以STM32F103C8T6单片机作为主控芯片,传感器采集大棚的CO2、温度、湿度参数,采用射频技术和通用分组无线服务(general packet radio service,简称GPRS)完成设备间的数据传输.通过继电器控制卷帘的升降、补光灯的亮灭和喷灌设备的启停.通过Web客户端能实现存储和显示数据.实验结果表明该系统达到了设计要求.该系统能实现远距离、低成本、高精度的监测,具有低功耗、可扩展的优点.展开更多
This short review deals with soils as an important source of the greenhouse gas N2O. The production and consumption of N2O in soils mainly involve biotic processes: the anaerobic process of denitrification and the aer...This short review deals with soils as an important source of the greenhouse gas N2O. The production and consumption of N2O in soils mainly involve biotic processes: the anaerobic process of denitrification and the aerobic process of nitrification. The factors that significantly influence agricultural N2O emissions mainly concern the agricultural practices (N application rate, crop type, fertilizer type) and soil conditions (soil moisture, soil organic C content, soil pH and texture). Large variability of N2O fluxes is known to occur both at different spatial and temporal scales. Currently new techniques could help to improve the capture of the spatial variability. Continuous measurement systems with automatic chambers could also help to capture temporal variability and consequently to improve quantification of N2O emissions by soils. Some attempts for mitigating soil N2O emissions, either by modifying agricultural practices or by managing soil microbial functioning taking into account the origin of the soil N2O emission variability, are reviewed.展开更多
基金Supported by the National Natural Science Foundation of China (No. 40971148)the Program of 100 Distinguished Young Scientists of the Chinese Academy of Sciences
文摘In northwestern China, there has been a change from traditional cultivation system （TC） with no mulching and flood irrigation to a more modern cultivation system （MC） using plastic film mulching with drip irrigation. A field study was conducted to compare soil ＇C02 concentrations and soil surface COs fluxes between TC and MC systems during a cotton growing season. CO2 concentrations in the soil profile were higher in the MC system （3107-9212μL L-1） than in the TC system （1 275-8994 μL L-1） but the rate of CO2 flux was lower in the MC system. Possible reasons for this included decreased gas diffusion and higher soil moisture due to the mulching cover in the MC system, and the consumption of soil CO2 by weathering reactions. Over the whole cotton growing season, accumulated rates of CO2 flux were 300 and 394 g C m-2 for the MC and TC systems, respectively. When agricultural practices were converted from traditional cultivation to a plastic film mulching system, soil CO2 emissions could be reduced by approximately 100 g C m-2 year-1 in agricultural lands in arid and/or semi-arid areas of northern and northwestern China.
文摘为解决农业大棚种植环境监测的近距离、高成本、低精度问题,设计并实现一种太阳能供电的农业大棚环境监测系统.以STM32F103C8T6单片机作为主控芯片,传感器采集大棚的CO2、温度、湿度参数,采用射频技术和通用分组无线服务(general packet radio service,简称GPRS)完成设备间的数据传输.通过继电器控制卷帘的升降、补光灯的亮灭和喷灌设备的启停.通过Web客户端能实现存储和显示数据.实验结果表明该系统达到了设计要求.该系统能实现远距离、低成本、高精度的监测,具有低功耗、可扩展的优点.
基金Supported by the Region Centre, the Fonds Européen de Développement Régional and the INRA, France, through the SpatioFlux Program
文摘This short review deals with soils as an important source of the greenhouse gas N2O. The production and consumption of N2O in soils mainly involve biotic processes: the anaerobic process of denitrification and the aerobic process of nitrification. The factors that significantly influence agricultural N2O emissions mainly concern the agricultural practices (N application rate, crop type, fertilizer type) and soil conditions (soil moisture, soil organic C content, soil pH and texture). Large variability of N2O fluxes is known to occur both at different spatial and temporal scales. Currently new techniques could help to improve the capture of the spatial variability. Continuous measurement systems with automatic chambers could also help to capture temporal variability and consequently to improve quantification of N2O emissions by soils. Some attempts for mitigating soil N2O emissions, either by modifying agricultural practices or by managing soil microbial functioning taking into account the origin of the soil N2O emission variability, are reviewed.
