为探索玉米-大豆套作系统中作物对N素吸收的差异特性,揭示减量施N对玉米-大豆套作系统的N高效利用机理。利用15N同位素示踪技术,结合小区套微区多年定位试验,研究了玉米单作(MM)、大豆单作(SS)、玉米-大豆套作(IMS)及不施N(NN)、减量施N...为探索玉米-大豆套作系统中作物对N素吸收的差异特性,揭示减量施N对玉米-大豆套作系统的N高效利用机理。利用15N同位素示踪技术,结合小区套微区多年定位试验,研究了玉米单作(MM)、大豆单作(SS)、玉米-大豆套作(IMS)及不施N(NN)、减量施N(RN:180 kg N/hm2)、常量施N(CN:240 kg N/hm2)下玉米、大豆的生物量、吸N量、N肥利用率及土壤N素含量变化。结果表明,与MM(SS)相比,IMS下玉米茎叶及籽粒的生物量、吸N量降低,15N%丰度及15N吸收量增加,大豆籽粒及植株的生物量、吸N量及15N吸收量显著提高;IMS下玉米、大豆植株的N肥利用率、土壤N贡献率、土壤15N%丰度降低,15N回收率显著增加。施N与不施N相比,显著提高了单、套作下玉米、大豆植株的生物量、吸N量、15N丰度及15N吸收量;RN与CN相比,IMS下,RN的玉米、大豆植株总吸N量提高13.4%和12.4%,N肥利用率提高213.0%和117.5%,土壤总N含量提高12.2%和11.6%,土壤N贡献率降低12.0%和11.2%,玉米植株15N吸收量与15N回收率提高14.4%和52.5%,大豆的则降低57.1%和42.8%,单作与套作的变化规律一致。玉米-大豆套作系统中作物对N素吸收存在数量及形态差异,减量施N有利于玉米-大豆套作系统对N肥的高效吸收与利用,实现作物持续增产与土壤培肥。展开更多
Salt stress is a vital factor limiting nitrogen uptake and cotton growth in arid regions.The mechanisms underlying salt stress tolerance in cotton plants under high soil salinity have not been fully elucidated.Therefo...Salt stress is a vital factor limiting nitrogen uptake and cotton growth in arid regions.The mechanisms underlying salt stress tolerance in cotton plants under high soil salinity have not been fully elucidated.Therefore,the aim of this study was to examine the proportion and mechanism of cotton nitrogen uptake under salt stress using the^(15)N isotope labeling technique.Cotton plants were grown in four undisturbed saline soils(1,3,6 and 9 dS m^(-1)),and the experiment was designed using the ENVIRO-GRO(E-G)model.The results showed that the dry matter of roots,stems and leaves of the cotton parts in slightly saline soil(C2,3 dS m^(-1))was not significant compared with the non-saline soil(C1,1 dS m^(-1)).The cotton fruit grown in low-salinity soil(C2,3 dS m^(-1))had significantly higher dry matter than that grown in the other treatments,implying that cotton plants grown in 3 dS m^(-1)soil have the best nitrogen uptake and salt tolerance.Cotton plants grown in weakly(C3,6 dS m^(-1))and moderately(C4,9 dS m^(-1))saline soils exhibited premature senescence.The distribution of total nitrogen and nitrate content in cotton was the best explanatory variable of total^(15)N recovery,of which cotton^(15)N recovery was between 26.1%and 47.2%,and soil^(15)N recovery was between 7.7%and 14.9%.Our findings provide guidance for further exploitation and utilization of saline soil resources and sustainable development of the agricultural soil ecosystem in arid regions.展开更多
文摘为探索玉米-大豆套作系统中作物对N素吸收的差异特性,揭示减量施N对玉米-大豆套作系统的N高效利用机理。利用15N同位素示踪技术,结合小区套微区多年定位试验,研究了玉米单作(MM)、大豆单作(SS)、玉米-大豆套作(IMS)及不施N(NN)、减量施N(RN:180 kg N/hm2)、常量施N(CN:240 kg N/hm2)下玉米、大豆的生物量、吸N量、N肥利用率及土壤N素含量变化。结果表明,与MM(SS)相比,IMS下玉米茎叶及籽粒的生物量、吸N量降低,15N%丰度及15N吸收量增加,大豆籽粒及植株的生物量、吸N量及15N吸收量显著提高;IMS下玉米、大豆植株的N肥利用率、土壤N贡献率、土壤15N%丰度降低,15N回收率显著增加。施N与不施N相比,显著提高了单、套作下玉米、大豆植株的生物量、吸N量、15N丰度及15N吸收量;RN与CN相比,IMS下,RN的玉米、大豆植株总吸N量提高13.4%和12.4%,N肥利用率提高213.0%和117.5%,土壤总N含量提高12.2%和11.6%,土壤N贡献率降低12.0%和11.2%,玉米植株15N吸收量与15N回收率提高14.4%和52.5%,大豆的则降低57.1%和42.8%,单作与套作的变化规律一致。玉米-大豆套作系统中作物对N素吸收存在数量及形态差异,减量施N有利于玉米-大豆套作系统对N肥的高效吸收与利用,实现作物持续增产与土壤培肥。
基金The work was supported by the National Natural ScienceFoundationof China(51969027,U1803244)Major Scientific and Technological Projects of XPCC in China(2017AA002,2021AB021)+1 种基金China Scholarship Council(201909505014)Shihezi University(CXRC201801,RCZK2018C22).
文摘Salt stress is a vital factor limiting nitrogen uptake and cotton growth in arid regions.The mechanisms underlying salt stress tolerance in cotton plants under high soil salinity have not been fully elucidated.Therefore,the aim of this study was to examine the proportion and mechanism of cotton nitrogen uptake under salt stress using the^(15)N isotope labeling technique.Cotton plants were grown in four undisturbed saline soils(1,3,6 and 9 dS m^(-1)),and the experiment was designed using the ENVIRO-GRO(E-G)model.The results showed that the dry matter of roots,stems and leaves of the cotton parts in slightly saline soil(C2,3 dS m^(-1))was not significant compared with the non-saline soil(C1,1 dS m^(-1)).The cotton fruit grown in low-salinity soil(C2,3 dS m^(-1))had significantly higher dry matter than that grown in the other treatments,implying that cotton plants grown in 3 dS m^(-1)soil have the best nitrogen uptake and salt tolerance.Cotton plants grown in weakly(C3,6 dS m^(-1))and moderately(C4,9 dS m^(-1))saline soils exhibited premature senescence.The distribution of total nitrogen and nitrate content in cotton was the best explanatory variable of total^(15)N recovery,of which cotton^(15)N recovery was between 26.1%and 47.2%,and soil^(15)N recovery was between 7.7%and 14.9%.Our findings provide guidance for further exploitation and utilization of saline soil resources and sustainable development of the agricultural soil ecosystem in arid regions.
