Straw return is an effective management practice. It not only utilizes agricultural waste but also introduces dissolved organic matter(DOM) into the soil. Selenium(Se) is an essential trace element in the human diet a...Straw return is an effective management practice. It not only utilizes agricultural waste but also introduces dissolved organic matter(DOM) into the soil. Selenium(Se) is an essential trace element in the human diet and contributes to the popularity of Se-enriched agricultural products in the Chinese market. Moreover, there are still some Se-enriched agricultural products that have yet to be utilized. This study investigated whether Se addition in soil caused component changes in the DOM extracted from rape straw. DOM extracted from rape straw grown in soil with four Se levels(0, 0.1, 0.5 and 1.0 mg Se kg-1 soil) was characterized by UV-Visible spectroscopy, fluorescence spectroscopy and FTIR spectroscopy. The UVvisible spectra revealed that 0.1 mg Se kg-1 soil reduced the molecular weight of DOM and caused the presence of more irreplaceable aromatic structures in the substituent groups of the DOM, while 0.5 and 1.0 mg Se kg-1 soil only reduced the DOM molecular weight. Fluorescence spectroscopy indicated that Se improved the humification degree but reduced the aromaticity of DOM. FTIR spectra proved that Se altered the contents of carboxylic acids, amino acids, alcohols and aromatic heterocycles in DOM, which were maximized in the 0.5 and 1.0 mg Se kg-1 treatment groups. We concluded that Se application could change the composition of DOM extracted from rape straw, potentially impacting the nutrient bioavailability in soil. This study provides basic data on Se-enriched rape straw utilization for eco-agriculture.展开更多
Screening of cost-effective soil amendments is important to develop ＂in situ＂ remediation techniques for cadmium （Cd） contaminated soils. In this study, different soil amendments, including red mud, a by-product o...Screening of cost-effective soil amendments is important to develop ＂in situ＂ remediation techniques for cadmium （Cd） contaminated soils. In this study, different soil amendments, including red mud, a by-product of the alumina industry, and acid-treated, nano-treated by nanoparticle milling, nano and acid-treated red muds, zeolite, corn straw, and rape straw, were evaluated to immobilize Cd in two added levels （2 and 5 mg Cd·kg^-1 soil） in a calcareous soil by single and sequential extractions and by cucumber （Cucumis sativus L.） pot experiments. Results indicated that cruciferous rape straw significantly decreased the concentrations of water soluble, extractable Cd in soils, and Cd in cucumber plants, and it was more effective than gramineous corn straw. Also, red mud generally decreased the extractability and bioavailability of Cd added to calcareous soils more effectively than zeolite. Furthermore, the efficiency of red mud could be increased by the treatment of nano-particle milling due to the increase in specific surface area of red mud. It is potential to use rape straw and red mud as soil amendments to develop a cost-effective and efficient ＂in situ＂ rernediation technology for Cd mildly contaminated calcareous soils.展开更多
基金This work was supported by the National Natural Science Foundation of China(41571321 and 31201501)the Fundamental Research Funds for the Central Universities of China(2662018JC057)the Opening Project of Key Laboratory of Testing and Evaluation for Agro-product Safety and Quality,Ministry of Agriculture and Rural Affairs of China(NK201702).
文摘Straw return is an effective management practice. It not only utilizes agricultural waste but also introduces dissolved organic matter(DOM) into the soil. Selenium(Se) is an essential trace element in the human diet and contributes to the popularity of Se-enriched agricultural products in the Chinese market. Moreover, there are still some Se-enriched agricultural products that have yet to be utilized. This study investigated whether Se addition in soil caused component changes in the DOM extracted from rape straw. DOM extracted from rape straw grown in soil with four Se levels(0, 0.1, 0.5 and 1.0 mg Se kg-1 soil) was characterized by UV-Visible spectroscopy, fluorescence spectroscopy and FTIR spectroscopy. The UVvisible spectra revealed that 0.1 mg Se kg-1 soil reduced the molecular weight of DOM and caused the presence of more irreplaceable aromatic structures in the substituent groups of the DOM, while 0.5 and 1.0 mg Se kg-1 soil only reduced the DOM molecular weight. Fluorescence spectroscopy indicated that Se improved the humification degree but reduced the aromaticity of DOM. FTIR spectra proved that Se altered the contents of carboxylic acids, amino acids, alcohols and aromatic heterocycles in DOM, which were maximized in the 0.5 and 1.0 mg Se kg-1 treatment groups. We concluded that Se application could change the composition of DOM extracted from rape straw, potentially impacting the nutrient bioavailability in soil. This study provides basic data on Se-enriched rape straw utilization for eco-agriculture.
基金This work was financially supported by Special Fund for Agro-scientific Research in the Public Interest （No. 200903015） 973 Program （No. 2014CB238906） and 863 Program （No. 2013AA06A21r2）. We are also very grateful to the National Natural Science Foundation of China （Grant No. 41201312, 41250110528） for financial support.
文摘Screening of cost-effective soil amendments is important to develop ＂in situ＂ remediation techniques for cadmium （Cd） contaminated soils. In this study, different soil amendments, including red mud, a by-product of the alumina industry, and acid-treated, nano-treated by nanoparticle milling, nano and acid-treated red muds, zeolite, corn straw, and rape straw, were evaluated to immobilize Cd in two added levels （2 and 5 mg Cd·kg^-1 soil） in a calcareous soil by single and sequential extractions and by cucumber （Cucumis sativus L.） pot experiments. Results indicated that cruciferous rape straw significantly decreased the concentrations of water soluble, extractable Cd in soils, and Cd in cucumber plants, and it was more effective than gramineous corn straw. Also, red mud generally decreased the extractability and bioavailability of Cd added to calcareous soils more effectively than zeolite. Furthermore, the efficiency of red mud could be increased by the treatment of nano-particle milling due to the increase in specific surface area of red mud. It is potential to use rape straw and red mud as soil amendments to develop a cost-effective and efficient ＂in situ＂ rernediation technology for Cd mildly contaminated calcareous soils.
文摘油菜(Brassica napus L.)秸秆作为重要的生物质资源,在环境保护和经济效益方面有着显著优势,具有高纤维素含量、利用成本低等优点,合理的利用可为相关产业原料的供应提供重要保障。湖南省作为中国油菜主产区,理论上具备产业化开发的潜力。全面了解生物质产量潜力和原料品质的区域差异是合理利用秸秆资源的前提与基础。因此,该研究对湖南省油菜秸秆资源产量潜力和原料品质空间异质性进行研究,基于此对油菜秸秆作为未来生物质产业原料的潜力进行评估。结果表明:湖南省油菜秸秆年产量为660.47万t,其中以湘北(35.71%)和湘中地区(32.43%)贡献最大,产量潜力分别达到了235.84万t和214.21万t。湖南省油菜秸秆生物质原料品质存在较高的异质性,所有表征指标的变异系数(coefficient of variation,CV)值均很高(>0.50)。生物质原料品质差异主要表现在重金属含量方面(CV>5.00)。此外,油菜秸秆生物质在灰分含量(CV=3.02)、木质素含量(CV=1.17)和纤维素聚合度(CV=1.15)方面也具有较为明显的差异。基于测定的多项品质指标,该研究通过构建基于隶属函数的生物质生产潜力指数进行原料品质指标的归一化处理。从生物质生产潜力指数上看,湖南省油菜秸秆最适合生产半纤维素基产品,尤其是湘北地区的油菜秸秆(潜力指数为0.60)。总体上看,具备较高产量潜力和较优原料品质的湘北地区可作为全省油菜秸秆产业的先行原料供应区。
