为探索涝渍连续抑制天数指标作为水稻排水标准,通过测坑模拟水稻抽穗开花期涝渍连续动态试验,构建了水稻涝渍连续抑制天数指标(Continuous Stress-Day Index of Water Logging,CSDI)的模型,提出了CSDI和涝害权重系数的求解方法,通过对...为探索涝渍连续抑制天数指标作为水稻排水标准,通过测坑模拟水稻抽穗开花期涝渍连续动态试验,构建了水稻涝渍连续抑制天数指标(Continuous Stress-Day Index of Water Logging,CSDI)的模型,提出了CSDI和涝害权重系数的求解方法,通过对实测数据的分析,建立了水稻相对产量与CSDI的关系模型。研究结果表明:单纯受渍和涝渍连续灾害均会造成水稻不同程度的减产,但涝渍连续灾害减产程度比单纯受渍高;涝害权重系数是一个随涝渍状态变化而变化的状态变量;在涝渍连续情况下,水稻的相对产量与CSDI具有良好的线性关系,涝渍连续抑制天数指标可作为水稻排水设计标准。利用文中CSDI的模型,可制定水稻控制排水策略。展开更多
Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-c...Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-contaminated paddy soil was incubated for 40days of flooding and then for 15 days of drainage,and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated.The addition of ZVI to the flooding process was more conducive to Cd immobilization.Less potential available Cd was detected by adding ZVI before flooding,which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals.Moreover,the reductive dissolution of Fe minerals promoted the release of soil colloids,thereby increasing significantly the surface sites and causing Cd immobilization.Additionally,the addition of ZVI before flooding played a vital role in Cd retention after soil drainage.In contrast,the addition of ZVI in the drainage phase was not conducive to Cd retention,which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces.The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.展开更多
文摘为探索涝渍连续抑制天数指标作为水稻排水标准,通过测坑模拟水稻抽穗开花期涝渍连续动态试验,构建了水稻涝渍连续抑制天数指标(Continuous Stress-Day Index of Water Logging,CSDI)的模型,提出了CSDI和涝害权重系数的求解方法,通过对实测数据的分析,建立了水稻相对产量与CSDI的关系模型。研究结果表明:单纯受渍和涝渍连续灾害均会造成水稻不同程度的减产,但涝渍连续灾害减产程度比单纯受渍高;涝害权重系数是一个随涝渍状态变化而变化的状态变量;在涝渍连续情况下,水稻的相对产量与CSDI具有良好的线性关系,涝渍连续抑制天数指标可作为水稻排水设计标准。利用文中CSDI的模型,可制定水稻控制排水策略。
基金supported by the National Natural Science Foundation of China(Nos.42277034 and 42207249)the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110904)+1 种基金the Guangdong Academy of Sciences(GDAS)Project of Science and Technology Development(No.2022GDASZH-2022010105)the Guangdong Foundation for Program of Science and Technology Research(No.2020B1212060048)。
文摘Zero-valent iron(ZVI)is a promising material for the remediation of Cd-contaminated paddy soils.However,the effects of ZVI added during flooding or drainage processes on cadmium(Cd)retention remain unclear.Herein,Cd-contaminated paddy soil was incubated for 40days of flooding and then for 15 days of drainage,and the underlying mechanisms of Cd immobilization coupled with Fe/S/N redox processes were investigated.The addition of ZVI to the flooding process was more conducive to Cd immobilization.Less potential available Cd was detected by adding ZVI before flooding,which may be due to the increase in paddy soil pH and newly formed secondary Fe minerals.Moreover,the reductive dissolution of Fe minerals promoted the release of soil colloids,thereby increasing significantly the surface sites and causing Cd immobilization.Additionally,the addition of ZVI before flooding played a vital role in Cd retention after soil drainage.In contrast,the addition of ZVI in the drainage phase was not conducive to Cd retention,which might be due to the rapid decrease in soil pH that inhibited Cd adsorption and further immobilization on soil surfaces.The findings of this study demonstrated that Cd availability in paddy soil was largely reduced by adding ZVI during the flooding period and provide a novel insight into the mechanisms of ZVI remediation in Cd-contaminated paddy soils.
