Effects Of Different Intercropping Patterns And Fertilization Treatments On Cd Uptake By Maize

In this study,aimed at the different of Cd uptake and translocation under different accumulators and maize intercropping mode.Meanwhile study the absorption and transport characteristics of agronomic measures of different fertilization regulation to maize and accumulators under intercropping.This paper based on the investigation and screening of different accumulators in the prophase,selected three kinds of accumulators with large biomass and could accumulate Cd,Through the pot experiment to study the difference of Cd uptake and translocation under different accumulators and maize intercropping,therefore selected the most suitable accumulator that intercropping with maize;by studying the effects of different forms of nitrogen fertilizer and different nitrogen application rates to the Cd content and available Cd content of soil,the effect of Cd uptake and transport in maize and accumulator under intercropping mode,in order to achieve the purpose of production and remediation at the same time,to obtain maize grain that conforming the national food safety standards and provide a theoretical basis and technical support for popularizing intercropping mode.The main conclusions of this study are as follows:?1?Intercropping of Amaranthus mangostanus L.,Lolium perenne L.and S.nigrum made the content of Cd in shoots of maize significantly decreased?P<0.05?,and the decrease of Cd content in grain was the most significant.The content of maize grain under intercropping Amaranthus mangostanus L.,Lolium perenne L.and S.nigrum decreased 67.6%,75.7%and 79.9%,respectively.Compared the maize moncropping,the intercropping of Amaranthus mangostanus L.,Lolium perenne L.and S.nigrum made the enrichment factor of maize decreased 49.3%,39.7%,and68.5%,respectively.Compared intercropping Amaranthus mangostanus L.and Lolium perenne L.,under intercropping S.nigrum,the transfer factors of maize decreased by 27.5%and 24.2%,respectively,and the difference reached a significantly level.?2?The content of Cd in the shoots of S.nigrum was:CK<Ca?NO₃?₂<?NH4?₂SO₄.Compared with NO3^--N,under NH₄⁺-N treatment,the Cd content of stems,leaves and grain of S.nigrum increased by 9.43%,22.2%and 8.33%,the difference reached a significant level?P<0.05?;the Cd content of stem,leaf and grain of maize decreased by 26.5%,21.2%and 21.4%,respectively,and the difference reached a significant level.Different forms of nitrogen fertilizer had different effects on the growth of maize and hyperaccumulator S.nigrum and the absorption and transport of heavy metals under intercropping mode.Compared the nitrate nitrogen fertilizer,ammonium nitrogen fertilizer could promote the absorption and transport of Cd by hyperaccumulator S.nigrum,The content of Cd in maize decreased significantly,and the content of Cd in soil decreased significantly,which improved the recovery efficiency of Cd with S.nigrum in contaminated soil.?3?N application will increase the Cd uptake by S.nigrum,and decrease the Cd absorption and translocation of maize instead under intercropping.Under maize and S.nigrum intercropping mode,the high nitrogen application rate of 0.2 g·kg^-1performs better than the N rate of 0.1 g·kg^-1 does.Therefore,relatively high N application rate is recommended for satisfactory bioremediation by Cd-hyperaccumulator S.nigrum and safe production of maize in Cd-contaminated soil,thus achieve the goal of production while remediation at the same time.