为探究干湿交替条件下,农田土壤CO_(2)排放对生物炭添加的响应特征及其影响因素,通过室外土柱模拟试验,在灰漠土中添加不同粒径棉花秸秆生物炭(<0.25 mm, M1;0.25~1 mm, M2;1~5 mm, M3;>5 mm, M4)和葡萄藤生物炭(<0.25 mm, P1;...为探究干湿交替条件下,农田土壤CO_(2)排放对生物炭添加的响应特征及其影响因素,通过室外土柱模拟试验,在灰漠土中添加不同粒径棉花秸秆生物炭(<0.25 mm, M1;0.25~1 mm, M2;1~5 mm, M3;>5 mm, M4)和葡萄藤生物炭(<0.25 mm, P1;0.25~1 mm, P2;1~5 mm,P3;>5 mm, P4),研究干湿交替下生物炭的类型、粒径对土壤CO_(2)排放特征的影响.结果表明,添加生物炭改变了土壤CO_(2)排放速率,土壤CO_(2)累积排放量随棉花秸秆生物炭粒径的增加而降低,不同生物炭类型对土壤CO_(2)排放速率的影响存在极显著差异(p <0.001).在湿润阶段,棉花秸秆生物炭处理土壤CO_(2)累积排放量为20.67~28.26 g·m^(-2)·d^(-1),与其相比,同一粒径下葡萄藤生物炭处理土壤CO_(2)累积排放量显著降低,降低了13.18%~28.83%;在干旱阶段,与对照处理相比,葡萄藤生物炭处理下土壤CO_(2)累积排放量显著降低了30.62%~45.09%(P3除外).土壤呼吸温度敏感系数(Q_(10))随葡萄藤生物炭粒径的增大而降低,最大降低了17.35%,而棉花秸秆生物炭处理下Q_(10)则提高了0.46%~6.39%(M4除外).指数拟合结果表明,土壤温度、湿度可分别解释土壤CO_(2)排放速率变化的39%~55%和4%~81%.单变量方差分析表明,干湿交替、生物炭类型以及生物炭粒径均是影响土壤CO_(2)排放的因素.展开更多
Heavy metal contamination of agricultural soils poses risks and hazards to humans. The remediation of heavy metal-polluted soils has become a hot topic in environmental science and engineering. In this review, the app...Heavy metal contamination of agricultural soils poses risks and hazards to humans. The remediation of heavy metal-polluted soils has become a hot topic in environmental science and engineering. In this review, the application of clay minerals for the remediation of heavy metal-polluted agricultural soils is summarized, in terms of their remediation effects and mechanisms, influencing factors, and future focus. Typical clay minerals, natural sepiolite, palygorskite, and bentonite, have been widely utilized for the in-situ immobilization of heavy metals in soils, especially Cd-polluted paddy soils and wastewater-irrigated farmland soils. Clay minerals are able to increase soil pH, decrease the chemical-extractable fractions and bioavailability of heavy metals in soils, and reduce the heavy metal contents in edible parts of plants. The immobilization effects have been confirmed in field-scale demonstrations and pot trials. Clay minerals can improve the environmental quality of soils and alleviate the hazards of heavy metals to plants. As main factors affecting the immobilization effects, the pH and water condition of soils have drawn academic attention. The remediation mechanisms mainly include liming, precipitation, and sorption effects. However, the molecular mechanisms of microscopic immobilization are unclear. F^ture studies should focus on the long-term stability and improvement of clay minerals in order to obtain a better remediation effect.展开更多
Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint st...Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.展开更多
文摘为探究干湿交替条件下,农田土壤CO_(2)排放对生物炭添加的响应特征及其影响因素,通过室外土柱模拟试验,在灰漠土中添加不同粒径棉花秸秆生物炭(<0.25 mm, M1;0.25~1 mm, M2;1~5 mm, M3;>5 mm, M4)和葡萄藤生物炭(<0.25 mm, P1;0.25~1 mm, P2;1~5 mm,P3;>5 mm, P4),研究干湿交替下生物炭的类型、粒径对土壤CO_(2)排放特征的影响.结果表明,添加生物炭改变了土壤CO_(2)排放速率,土壤CO_(2)累积排放量随棉花秸秆生物炭粒径的增加而降低,不同生物炭类型对土壤CO_(2)排放速率的影响存在极显著差异(p <0.001).在湿润阶段,棉花秸秆生物炭处理土壤CO_(2)累积排放量为20.67~28.26 g·m^(-2)·d^(-1),与其相比,同一粒径下葡萄藤生物炭处理土壤CO_(2)累积排放量显著降低,降低了13.18%~28.83%;在干旱阶段,与对照处理相比,葡萄藤生物炭处理下土壤CO_(2)累积排放量显著降低了30.62%~45.09%(P3除外).土壤呼吸温度敏感系数(Q_(10))随葡萄藤生物炭粒径的增大而降低,最大降低了17.35%,而棉花秸秆生物炭处理下Q_(10)则提高了0.46%~6.39%(M4除外).指数拟合结果表明,土壤温度、湿度可分别解释土壤CO_(2)排放速率变化的39%~55%和4%~81%.单变量方差分析表明,干湿交替、生物炭类型以及生物炭粒径均是影响土壤CO_(2)排放的因素.
基金supported by the Central Public Research Institutes Basic Funds for Research and Development, China (No. 2016-szjj-wrxf-lxf)the National Natural Science Foundation of China (No. 41401362)the Funds for Science and Technology Innovation Project from the Chinese Academy of Agricultural Sciences (No. CAAS-XTCX-2016018)
文摘Heavy metal contamination of agricultural soils poses risks and hazards to humans. The remediation of heavy metal-polluted soils has become a hot topic in environmental science and engineering. In this review, the application of clay minerals for the remediation of heavy metal-polluted agricultural soils is summarized, in terms of their remediation effects and mechanisms, influencing factors, and future focus. Typical clay minerals, natural sepiolite, palygorskite, and bentonite, have been widely utilized for the in-situ immobilization of heavy metals in soils, especially Cd-polluted paddy soils and wastewater-irrigated farmland soils. Clay minerals are able to increase soil pH, decrease the chemical-extractable fractions and bioavailability of heavy metals in soils, and reduce the heavy metal contents in edible parts of plants. The immobilization effects have been confirmed in field-scale demonstrations and pot trials. Clay minerals can improve the environmental quality of soils and alleviate the hazards of heavy metals to plants. As main factors affecting the immobilization effects, the pH and water condition of soils have drawn academic attention. The remediation mechanisms mainly include liming, precipitation, and sorption effects. However, the molecular mechanisms of microscopic immobilization are unclear. F^ture studies should focus on the long-term stability and improvement of clay minerals in order to obtain a better remediation effect.
基金This work was support by the National Natural Science Foundation of China as an overseas distinguished young scholars award(Grant No.20428707)as a key project(Grant No.20337010)by the Sino-Russia Joint Research Center on Natural Resources and Eco-Environmental Sciences.
文摘Rorippa globosa has been identified as a newly-found Cd-hyperaccumulating species.In the present study,growth responses of Rorippa globosa and its accumulation characteristics of Cd and As were examined under joint stress of Cd and As.The results showed that Cd and As had an antagonistic effect on enhancing the growth of Rorippa globosa plants and Cd uptake and accumulation under the low concentration Cd and As treatments.When the concentra-tion of Cd in the soil was 10 mg/kg and the concentration of As was 50 mg/kg,the highest growing height of the plant was up to 35.9 cm and the dry weight of the shoots was up to 2.2 g/pot,respectively.Meanwhile,the accumulation of Cd in the leaves under the joint stress was higher than that at the same level under single Cd pollution.However,there were synergic adverse effects on plant growth and Cd uptake under the combined pollution from a high concentration of Cd and As.Meanwhile,the accumulation of As in the roots was greater than that in the shoots,the translocation factor(TF)was h0.3 and the bioaccumulation factor(BF)was h0.6,thus showing that Rorippa globosa had an excluding effect on As uptake.These results confirmed that Rorippa globosa had a strong tolerant ability to the joint stress of Cd and As,and the potential for phytoremediation of soils contaminated by Cd and As.
