| This thesis studied sample plot by long-term monitoring on red soil upland ecosystems,red soil ecological,experiment station of red earth ecology,Chinese Academy of Sciences,through continuous application of different amounts of pig manure of intensive farms(dosage were 2.5,5.0,7.5,10,15,20,25 t/hm~2,applying a total of three times), and,determined the pH value,bulk density and other basic physical and chemical properties,the contents of Cu,Zn,Cd,Pb and other heavy metals in soil and the growth indexs and contents of heavy metals in different parts of Arachis hypogaea,winter Raphanus and Ixeris.Pig manure of Intensive pig farms had been studied and assessed to accumulation of heavy metals in upland and crops.Preliminary results were as follows: 1 Pig manure of intensive farms affected physical and chemical properties of red soil uplandAs the number and amount of fertilizer increasing,pH value and the density of Topsoil were trend toward lower,but,the content of organic carbon,the density of topsoil and the total nitrogen and phosphorus were increasing trend gradually,the content of organic carbon in Asia topsoil changing no significantly.Successive application of different amounts of pig manure impacted on K element in soil significantly.2 Different application amount of pig manure affected on rudimental accumulation of heavy metals of red soil uplandConcentration of Cu,Zn,Pb,Cd and the other heavy metals in Topsoil increased as the number of fertilizer application of pig manure increasing.Continuous application of pig manure affected Concentration of in topsoil and Pb,Cd prominently.Concentration of Cu,Zn in sub-topsoil increased as the number of fertilizer application of pig manure increasing,but Concentration of Pb,Cd having little changing.The concentration of heavy metals had no significant difference among all experiments.By analyzing between concentration of heavy metals in topsoil and the times of continuous application and amount of cumulating application of pig manure,there were positive correlation significantly between the concentration of Cu,Zn in topsoil and the concentrations and amount of cumulating application of Zn in sub-topsoil,with correlative coefficients. However,the concentrations of Cu,Pb,Cd had little pertinence with amount of cumulating application of pig manure.3 Environmental assessment of the application of pig manure of intensive farms and residual of heavy metals in the red soil upland Pollution index of heavy metals were all more than 1.0 if using the background as evaluation standard.But pollution index of Cu,Zn,Cr,Pb were all more than 0.7 which reaching a value of alert,but only Cd less than 0.7,if using the national soil quality standards evaluation standard.Pollution index of Cu,Zn were high,but less than 0.7 which showed no pollution,if using the second environmental standard as evaluation standard.Most heavy-metals contamination in the soil surface was low potential ecological risk, but Cd element was middling ecological risk,through continuous application of pig manure of three quarters.Potential ecological hazard indexes of heavy metals in soil was Cd＞Cu＞Pb＞Cr＞Zn.Ecological risk indexes(RI) became bigger and bigger with the amount and the frequencies of fertilizer increasing.4 Affect of different applying amount of pig manure of intensive farms on crops and quality evaluation on the edible parts4.1 Application of pig manure impacted on Arachis hypogaea and winter Raphanus,Ixeris biomass prominently.Arachis hypogaea biomass,grain yield,winter Raphanusand and Ixeris biomass of edible parts were all higher than the control experiment.4.2 Different applied amounts of pig manure impacted on the contents of heavy metals in different crops and different parts differently.The contents of Cu aboveground of Ixeris was the highest,following by the root of Ixeris and Arachis hypogaea seeds,the lowest level in the winter Raphanus.The contents of heavy metals in Ixeris and Arachis hypogaea became higher and higher with amounts of fertilizer application increasing,but it was trend toward low in winter Raphanus.When amount of fertilizer application was more than 10t/hm~2,concentrations of Cu in aboveground of Ixeris and Arachis hypogaea seeds were all higher than the maximum permitted concentration in vegetables,but it was lower than the limit concentration in winter Raphanus managed.The most of contents of Zn in these crops were higher than control experiment.The contents of Zn aboveground of Ixeris was the highest,following by the Arachis hypogaea seeds,the lowest content in the winter Raphanus.Concentrations of Zn in Ixeris and Arachis hypogaea seeds were all higher than the maximum permitted concentration.But it was lower than standard values in winter Raphanus.The contents of Pb in winter Raphanus and Arachis hypogaea which were managed by pig manure became higher with amounts of fertilizer application increasing,but it was lower than that in Ixeris and not monitored in Arachis hypogaea seeds.Concentrations of Zn in winter Raphanus and Ixeris were all higher than the maximum permitted concentration. The contents of Cd in Arachis hypogaea which became higher and higher with amounts of fertilizer increasing were all higher than that of control experiment and most of contents in Arachis hypogaea seeds,aboveground and root of Ixeris were higher than that of control experiment,but lower than that of control experiment in winterRaphanus.Concentrations of Cd in edible parts of each crop were all higher than the maximum permitted concentration in vegetables.The concentration of heavy metals was lower than national soil quality two standards,but the accumulation of heavy metals in crops was more than the maximum permitted concentration in food... |
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