有机肥-镉-锌交互作用对土壤镉锌形态和小麦生长的影响

 模拟不同镉锌污染与有机肥(猪厩肥)施用水平,进行春小麦盆栽试验,采用Tessier法测试土壤中重金属形态.结果表明,复合污染时在同水平Cd(Zn)污染下,外源Zn(Cd)含量的增加使土壤中有效态Cd(Zn)的含量提高,小麦籽粒中Cd(Zn)含量增加(降低),而小麦籽粒产量均下降,差异极显著.施入猪厩肥降低了土壤中有效态Cd、铁锰氧化物结合态Cd的含量提高了土壤中有效态Zn、碳酸盐态Zn含量;降低了铁锰氧化物结合态Zn的含量.小麦籽粒中Zn含量并没有完全随土壤中有效态Zn增加而增加,在Zn/Cd为100～1000的处理中,施用猪厩肥反而降低了小麦籽粒中Zn含量;除Zn/Cd为100～10的处理中小麦籽粒中Cd含量有所下降外,其余处理中,施用猪厩肥小麦籽粒中Cd含量均有所增加.猪厩肥的施用能显著提高Cd、Zn污染土壤中小麦籽粒产量.

Effects of interaction by organic manure-Cd-Zn on Cd, Zn formation in soil and wheat growth

Simulating different levels of Cd, Zn pollution and organic manure (pig manure) spreading, spring wheat potexperiments were carried out; and formations of the heavy metals in soil were determined by Tessier method. The results showed that: at combined pollution under same Cd(Zn) pollution level, available Cd(Zn) content increased in the soil as the added Zn(Cd) content increased; and contents of Cd(Zn) in grain increased (decreased) while the wheat grain yieldalways decreased. The difference was very marked. Organic manure spreading decreased Cd content of available and iron-manganese oxide form; increased Zn content of the available and carbonate forms; and decreased Zn content of iron-manganese oxide. Zn contents in grain were not increased completely by increasing Zn available contents in soil; on the contrary, pig manure spreading decreased Zn contents in grain at treatments by added Zn/Cd=100~1000; and increased Cd contents in grain at other treatments, except treatments by added Zn/Cd=100~10. Pig manure markedly increased wheat grain yield in soil polluted by Cd, Zn.