Effect Of Different Water Managements On Rice Root Iron Plaque And Cadmium Accumulation

This article researched the effects on the formation of root iron membrane under the three different water managements.Including flooding,intermittent and wetting irrigation,and the effects on rice cadmium stresses,plant height,tiller,yield,Cd accumulation;microbial biomass carbon and nitrogen,soil enzyme activity,root iron plaque,manganese membrane,FRB and forms of cadmium to provide guidance for safety of growing rice.The results showed as follows:1.The formation of root iron membrane shows different tendencies in the three different water managements.Under the flooding irrigation,the formation of root iron membrane shows the tendency of rises first and fall later;Under the intermittent irrigation,rice has more root iron membrane than flooding.Without iron-induced,the growing rate reach 253.70% during the booting stage,the difference between intermittent irrigation and flooding is significance.Under the wetting irrigation,the tendency is decline.2.Compare with the flooding irrigation,intermittent irrigation makes the Iron oxide bacteria number larger.With iron-induced(Fe20),the Iron oxide bacteria number increases 16.67%.And the number of iron-reducing bacteria is smaller.Without iron-induced,it reduced 35.95% during the booting stage.With the increase of cadmium,the number of iron-reducing bacteria shows the tendency of reducing.3.Compare with the flooding irrigation,intermittent irrigation can increase the soil microbial biomass carbon and nitrogen.With iron-induced(Fe20),it increases37.32% and 24.29% during the booting stage.Compare with the intermittent irrigation,wetting irrigation makes the microbial biomass carbon and nitrogen less.The difference is significance.4.Under the different water managements,the iron-induced has little effect on yield and ingredients.More cadmium makes the yield reduced.Without iron-induced,the yield of intermittent irrigation increases 14.83% compared to flooding.5.under the same water management,iron-induced makes the validity of cadmium reduced,and makes the content of acid-soluble cadmium and reducible cadmium.At the same time,it increases the content of oxidable cadmium.6.The Cd accumulation in root,stem and leaf,brown rice of rice was decreased under the induction of iron,while Fe20 and Fe40 treatments reduced the Cd content of Cd1 by 19.70% and 31.86% respectively,the Cd content in stem and leaf decreased by 10.86% and 19.56%,and Cd content in brown rice decreased by 18.51% and33.33%,respectively.When dry and wet alternate irrigation,Fe20 and Fe40 treatments reduced the Cd content of Cd1 by 30.53% and 39.24% respectively,and the Cd content in stems and leaves decreased by 18.75% and 28.12%,and Cd content in brown rice decreased by 10.73% and 15.18% respectively.In wet irrigation,Fe20 and Fe40 treatments reduced the Cd content in the Cd1 by 30.89% and 41.01%,respectively,and the Cd content in the leaves decreased by 18.40% and 29.60%,and the Cd content in brown rice decreased by 17.74% and 24.19%,respectively.