水分管理方式对水稻在Cd污染土壤上生长及其吸收Cd的影响

通过水稻盆栽试验,研究了Cd污染土壤上旱作、不同生育期烤田和全生育期淹水等不同水分管理方式对水稻生长及其吸收Cd的影响.结果表明,旱作栽培对水稻生长发育影响较大,水稻产量较低,与全生育期淹水栽培相比,产量下降了28.74%.全生育期淹水栽培具有一定的产量水平,但不是最高,分蘖期和灌浆期烤田比其产量提高14.58%和10.27%.在全生育期淹水栽培方式下,水稻糙米中Cd含量最低,旱作和不同生育期烤田,水稻籽粒中Cd的含量会增加,其中水稻旱作的增加最多,达166.31%,而灌浆乳熟期增加较少.研究表明,被Cd在一定程度上污染的土壤上种植水稻,采用旱作方式应慎重,以避免水稻旱作所带来的粮食品质的安全风险.

Effects of water control on rice growth and its intake of cadmium on Cd contaminated soil

The present article is aimed at reporting the authors' pot rice-growing experiments in hoping to investigate the effects of different ways of water control on rice yields and its intake of Cd,that is,continuous flooding,dry cultivation and mid-way drainage in different growing stages.The results of our experiments indicate that dry cultivation brings about remarkable effects on the rice growth and brings about the lowest yields.Compared with the continuous flooding,dry cultivation tends to decrease the rice yields by 28.74%.On the other hand,continuous flooding tends to bring about relatively higher yields,but not the highest.Drainage at tillering and filling periods could increase the rice yields more remarkably than continuous flooding,that is,by 14.58% vs.10.27%.The content of Cd in brown rice proves the least with the continuous flooding,while the dry cultivation and midseason drainage in different growing stages tend to increase its content in brown rice,which appears most obviously with dry cultivation.In our experiments,dry cultivation has brought about an increase of Cd content as high as by 166.31%.On the other hand,the influence on Cd content in brown rice with the mid-way drainage proves weakest.Thus,it can be concluded that continuous flooding is the most favorable to be chosen as a cultivation method on Cd contaminated soil,with the drainage cultivation following.In addition,dry cultivation is also likely to affect rice growth with an obvious increase of the Cd content,for which it is unfavorable to be chosen on Cd contaminated soil.