摘要
广西壮族自治区是我国水稻的主要产区之一。由于碳酸盐岩广泛出露,土壤Cd和As的高含量往往由地质高背景引起。有机Si肥料是一种新型的Si肥,可有效降低植物中重金属积累,但以前的研究主要集中在盆栽实验,对田间小区实验和大田实验效果了解甚少。本研究通过为期1年(2个生长季节)的田间小区水分管理和有机Si施用实验以及大田Si肥施用实验,探究不同农艺措施对Cd、As共污染阻控能力。结果表明,早稻大米中的Cd浓度(0.33±0.04~0.43±0.11 mg·kg^(-1))明显低于晚稻(0.77±0.02~1.27±0.13mg·kg^(-1)),而籽粒中As浓度(0.44±0.01~0.49±0.06 mg·kg^(-1))明显高于晚稻(0.10±0.01~0.10±0.02 mg·kg^(-1))。Si肥施用能有效降低水稻Cd积累,但对As的阻控效果不显著。另外,晒田会导致晚稻籽粒中Cd浓度升高22%。大田实验进一步证实了Si肥的施用可以使早稻中Cd浓度降低56%,晚稻降低53%。因而,稻田全生育期淹水,同时施加Si肥,可以有效阻控水稻对Cd的积累。
Guangxi is one of the main rice-producing areas in China.Due to the karst geomorphology,paddy field in Guangxi is often contaminated by cadmium(Cd)and arsenic(As),which are generally considered to be mainly of geological origin.Organic silicon(Si)fertilizer,a new type of silicon fertilizer,can effectively reduce the accumulation of heavy metals in plants.As our knowledge about Cd or As mitigation by Si fertilizer was mainly based on results from pot experiments,little is known about the effects of Si fertilizer in plot and field conditions.In this study,both plot experiment and field experiment were carried out to investigate the mediating effects of Si fertilization on Cd and As accumulation in rice in the two growing seasons of one year.The dual effects of water management and organic Si application were also explored in the plot experiment.The results showed that Cd concentration in early rice(0.33±0.04-0.43±0.11 mg·kg^(-1))was significantly lower than that in late rice(0.77±0.02-1.27±0.13 mg·kg^(-1)),while the As concentration in grains(0.44±0.01-0.49±0.06 mg·kg^(-1))in early rice was significantly higher than that in late rice(0.10±0.01-0.10±0.02 mg·kg^(-1)).The application of Si fertilizer substantially reduced Cd accumulation in rice,but did not affect As accumulation.Field drying increased Cd concentration in late rice grains by 22%.Results from the field experiment further confirmed that the application of Si fertilizer reduced Cd concentration in early rice by56%and late rice by 53%.Therefore,the accumulation of Cd in rice can be effectively controlled by flooding in the whole growing period and by applying Si fertilizer.
作者
姚保民
王树卿
李刚
孙国新
YAO Bao-min;WANG Shu-qing;LI Gang;SUN Guo-xin(State Key Laboratory of Urban and Regional Ecology,Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;University of Chinese Academy of Sciences,Beijing 100049,China;Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,Fujian,China;Ningbo Research Center for Urban Environment,Chinese Academy of Sciences,Ningbo 315800,Zhejiang,China)
出处
《生态学杂志》
CAS
CSCD
北大核心
2021年第8期2348-2356,共9页
Chinese Journal of Ecology
基金
国家重点研发计划(2017YFD0800303)资助。
关键词
Si肥
镉砷复合污染
水稻
田间实验
silicon fertilizer
cadmium and arsenic compound pollution
rice
field experiment
