Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.Ho...Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.However,quantitative assessments of differences in the N derived from rhizodeposition(NdfR)between legumes and gramineous crops are lacking,and comparative studies on their contributions to the subsequent cereals are scarce.In this study,we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide.In addition,pot experiments were conducted to study the differences in the NdfR amounts,distributions and subsequent effects of two major wheat(Triticum aestivum L.)-preceding crops,corn(Zea mays L.)and soybean(Glycine max L.),by the cotton wick-labelling method in the main wheat-producing areas of China.The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93%compared to gramineous crops.In our pot experiment,the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot,respectively,and soybean was also significantly higher than corn,accounting for 76.91 and 84.15%of the total belowground nitrogen of the plants,respectively.Moreover,in different soil particle sizes,NdfR was mainly enriched in the large macro-aggregates(>2 mm),followed by the small macro-aggregates(2–0.25 mm).The amount and proportion of NdfR in the macro-aggregates(>0.25 mm)of soybean were 3.48 and 1.66 times higher than those of corn,respectively,indicating the high utilization potential of soybean NdfR.Regarding the N accumulation of subsequent wheat,the contribution of soybean NdfR to wheat was approximately 3 times that of corn,accounting for 8.37 and 4.04%of the total N uptake of wheat,respectively.In conclusion,soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates.In future field production,legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops,and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.展开更多
Complex permittivity and electrical impedance have been measured along the c-axis in single crystals BaFe_2 As_2,which are the conductors known as the parent compound of 122-type iron superconductor. The resultant rel...Complex permittivity and electrical impedance have been measured along the c-axis in single crystals BaFe_2 As_2,which are the conductors known as the parent compound of 122-type iron superconductor. The resultant relative errors defined in the study indicate the existence of the transformation between complex permittivity and electrical impedance in the conductors, and these two physics quantities possibly reveal different aspects of the consistent superconductivityrelevant physics picture.展开更多
Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron strain(as Rnown as B.1.1.529)was identified in Botswana and South Africa in early November 2021 and was later defined as a new variant of ...Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron strain(as Rnown as B.1.1.529)was identified in Botswana and South Africa in early November 2021 and was later defined as a new variant of concern(VOC)by the World Health Organization on November 26,2021.1,2 To date,the con firmed cases of Omicro n have been reported in more than 38 countries,and the number of cases appears to be rapidly in creasing.SARS-CoV-2 Omicron could give rise to the fourth wave of the COVID-19 epidemic spreading around the world,following the D614G,Beta/Gamma,and Delta VOCs.展开更多
基金financially supported by the National Key Technology Research and Development Program of China(2021YFD1901001-08)the Key Scientific and Technological Project of Henan Provincial Education Department,China(232102111119)。
文摘Nitrogen(N)is a key factor in the positive response of cereal crops that follow leguminous crops when compared to gramineous crops in rotations,with the nonrecyclable rhizosphere-derived N playing an important role.However,quantitative assessments of differences in the N derived from rhizodeposition(NdfR)between legumes and gramineous crops are lacking,and comparative studies on their contributions to the subsequent cereals are scarce.In this study,we conducted a meta-analysis of NdfR from leguminous and gramineous crops based on 34 observations published worldwide.In addition,pot experiments were conducted to study the differences in the NdfR amounts,distributions and subsequent effects of two major wheat(Triticum aestivum L.)-preceding crops,corn(Zea mays L.)and soybean(Glycine max L.),by the cotton wick-labelling method in the main wheat-producing areas of China.The meta-analysis results showed that the NdfR of legumes was significantly greater by 138.93%compared to gramineous crops.In our pot experiment,the NdfR values from corn and soybean were 502.32 and 944.12 mg/pot,respectively,and soybean was also significantly higher than corn,accounting for 76.91 and 84.15%of the total belowground nitrogen of the plants,respectively.Moreover,in different soil particle sizes,NdfR was mainly enriched in the large macro-aggregates(>2 mm),followed by the small macro-aggregates(2–0.25 mm).The amount and proportion of NdfR in the macro-aggregates(>0.25 mm)of soybean were 3.48 and 1.66 times higher than those of corn,respectively,indicating the high utilization potential of soybean NdfR.Regarding the N accumulation of subsequent wheat,the contribution of soybean NdfR to wheat was approximately 3 times that of corn,accounting for 8.37 and 4.04%of the total N uptake of wheat,respectively.In conclusion,soybean NdfR is superior to corn in terms of the quantity and distribution ratio of soil macro-aggregates.In future field production,legume NdfR should be included in the nitrogen pool that can be absorbed and utilized by subsequent crops,and the role and potential of leguminous plants as nitrogen source providers in crop rotation systems should be fully utilized.
基金Project supported by the National Natural Science Foundation of China(Grant No.11004106)the National Basic Research Program of China(Grant No.2015CB946502)+1 种基金the Chinese Academy of Sciences(Grant No.SPRP-B:XDB25000000)the Youth Innovation Promotion Association of Chinese Academy of Sciences
文摘Complex permittivity and electrical impedance have been measured along the c-axis in single crystals BaFe_2 As_2,which are the conductors known as the parent compound of 122-type iron superconductor. The resultant relative errors defined in the study indicate the existence of the transformation between complex permittivity and electrical impedance in the conductors, and these two physics quantities possibly reveal different aspects of the consistent superconductivityrelevant physics picture.
基金This work was supported by the National Special Research Program of China for Important Infectious Diseases(2017ZX10202102 and 2018ZX10302103)to H.Z.National Natural Science Foundation of China(32100743 and 82171825)to X.H.+8 种基金the Special 2019-nCoV Project of the National Key Research and Development Program of China(2020YFC0841400)the Emergency Key Program of Guangzhou Laboratory(EKPG21-24)the Special 2019-nCoV Program of the Natural Science Foundation of China(NSFC)(82041002)the Special Research and Development Program of Guangzhou(202008070010)the Important Key Program of NSFC(81730060)to HZThis work was also supported by National Natural Science Foundation of China⑻971918)Shenzhen Science and Technology Program(Grant No.JSGG20200225150431472 and JCYJ20200109142601702)the Pearl River S&T Nova Program of Guangzhou(201806010118)the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(2021qntd43)to T.P.
文摘Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron strain(as Rnown as B.1.1.529)was identified in Botswana and South Africa in early November 2021 and was later defined as a new variant of concern(VOC)by the World Health Organization on November 26,2021.1,2 To date,the con firmed cases of Omicro n have been reported in more than 38 countries,and the number of cases appears to be rapidly in creasing.SARS-CoV-2 Omicron could give rise to the fourth wave of the COVID-19 epidemic spreading around the world,following the D614G,Beta/Gamma,and Delta VOCs.
