秸秆还田对稻田渗漏液DOC含量及土壤Cd活度的影响

通过盆栽试验,研究了秸秆还田对稻田渗漏液DOC含量及重金属污染土壤Cd溶出的影响。结果表明,秸秆还田增加了稻田渗漏液的DOC含量,提高了土壤Cd的活度。稻田渗漏水DOC的浓度随秸秆还田量的增加而增大。秸秆还田增加了Cd随稻田渗漏水的流失,使得稻田土壤Cd全量、有效态Cd量均随秸秆还田量的增加而降低,部分处理降低幅度达显著水平。本试验条件下由于较多的秸秆还田影响了水稻生长,使水稻植株Cd浓度、累积量均随秸秆还田量的增加呈先上升后下降的趋势。秸秆还田0.5%处理的水稻植株Cd浓度、累积量最高,分别为45.10mg·kg-1、1858.1μg·pot-1。

Effect of Wheat Straw Return on DOC in Percolating Water and Cd Activity in Rice Soil

A pot experiment was carried out to study the effect of straw return on dissolved organic carbon（DOC） in percolating water and Cd activity in a polluted rice soil.The results showed that DOC concentration in percolating water in rice soil increased with the increase of the amount of straw returned.After rice harvest,total and effective Cd in the soil decreased（or decreased significantly in some treatments） with the amount of straw added to the soil,due to enhanced loss of Cd through percolating water by addition of wheat straw.Under experimental conditions,with the increase of the amount of straw,Cd concentration and accumulation in rice plants,increased firstly and then decreased.Cd concentration and accumulation in plants in 0.5% straw returning treatment were the highest,which were 45.10 mg·kg-1,1 858.1 μg·pot-1 respectively.Straw returning elevated DOC concentration in percolating water and the activity of soil Cd in rice field.