摘要
菜稻菜轮作模式是由广东省农业科学院提出的一种高效利用并能改善土壤环境的耕作模式。为探讨菜稻菜模式对农田土壤重金属的影响,以蔬菜连作、水稻连作作为对照,在东莞市开展大田试验,研究菜稻菜模式下土壤Cd各赋存形态的分布特征、变化规律以及农作物可食部分对Cd含量的影响。结果表明,菜稻菜轮作和蔬菜连作对Cd全量及赋存形态无明显影响,水稻连作处理能降低耕层土壤Cd全量、可交换态、可氧化态、残渣态含量;土壤中Cd大多以活性较高的形态存在,各赋存形态的含量高低顺序为可交换态>可还原态>可氧化态>残渣态,土壤中Cd可还原态能与可氧化态、残渣态进行相互转化;水稻对Cd的富集能力要远高于蔬菜,在推广菜稻菜模式时要慎重考虑水稻Cd的超标风险。
Rice-Vegetable Rotation regime （RVRr）,which has been proposed by Guangdong Academy of Agricultural Sciences,was a highly effective farming model and advance soil environment.We carried out a field experiment in Dongguan to explore the impacts of RVRr on heavy metal cadmium （Cd）in farmland soil.In comparison with Vegetable Continuous Cropping regime（VCCr）and Rice Continuous Cropping regime（RCCr）,we aimed to get the distributional characteristics and migration rules of various Cd occurrence modes in soil,as well as accumulative laws of Cd in edible parts of crops under RVRr.The results showed that RVRr and VCCr had no significant influence on the contents of total Cd and its various occurrence modes.However,RCCr could significantly reduce the contents of exchangeable,oxidizable,residual form and the total Cd in soil.Cd was dominated in the high activity fractions in soil,and followed the order of exchangeable＞reducible＞oxidizable＞residual.Additionally,reducible form could transform with oxidizable and residual form.Rice had more cumulative capacity of Cd than vegetables,so that the risk of excessive Cd in rice should be carefully considered before extending RVRr.
出处
《热带作物学报》
CSCD
北大核心
2014年第7期1272-1277,共6页
Chinese Journal of Tropical Crops
基金
广东省科技攻关项目(No.2011B030900012)
广东省农业科学院院长基金项目(No.201120
201418)
惠州市科技计划项目产学研专项(No.20110804)
关键词
菜稻菜轮作
蔬菜连作
水稻连作
镉
赋存形态
Rice-vegetable rotation regime
Vegetable continuous cropping regime
Rice continuous cropping regime
Cadmium
Form distribution
