| 引用本文: | 葛颖,马进川,邹平,等.镉轻度污染稻田水分管理对水稻镉积累和镉生物有效性的影响[J].灌溉排水学报,0,():-. |
| Geying,MA Jin-chuan,ZOU Ping,et al.镉轻度污染稻田水分管理对水稻镉积累和镉生物有效性的影响[J].灌溉排水学报,0,():-. |
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| 摘要: |
| 【目的】为研究镉轻度污染农田水稻不同生育期水分管理对水稻镉积累和土壤镉生物有效性的影响，【方法】采用盆栽试验，分别设置水稻全生育期湿润灌溉（CK），全生育期淹水（T1），和拔节期（T2）、孕穗期（T3）、抽穗扬花期（T4）、灌浆乳熟期（T5）以及蜡熟期（T6）开始淹水7个处理，对水稻不同器官镉积累差异以及土壤氧化还原电位、根际土壤溶液水溶性镉含量变化进行研究。【结果】相关分析表明土壤氧化还原电位与水溶性Cd呈极显著正相关（p<0.01），淹水后土壤的氧化还原电位显著降低，土壤还原性增强，淹水时间越长的处理氧化还原电位越低，其中T1处理最低可降至-159.78 mV，淹水后根际土壤溶液中水溶性Cd也迅速下降，T3处理下降最多，为78.2%。不同水分管理模式下水稻糙米镉含量均未超过食品安全国家标准规定的限量值（GB2762-2017）。与CK处理相比，T1处理降低稻米镉含量达76.9%，而水稻产量明显下降，减产19.2%；T6处理明显抑制镉从水稻根系向地上部分转移，增加根系镉质量占比15.2%；T6处理降低水稻茎秆的镉积累，降低茎秆镉质量占比13.0%；淹水通过抑制镉从水稻叶片向谷物的转移来降低稻米镉积累，与对照相比，T5处理最高增加叶片镉质量占比5.0%，T3处理最高降低谷物镉质量占比4.3%。【结论】综合考虑水稻产量、稻米镉含量和田间农事操作习惯，镉轻度污染稻田推荐的水分调控方式为抽穗扬花期淹水至收获前一周。 |
| 关键词: 水分管理;水稻生育期;镉; 氧化还原电位;孔隙水;水溶性Cd |
| DOI： |
| 分类号:S511; X53 |
| 基金项目:浙江省重点研发项目(2018C03047,2015C03020)；浙江省自然科学基金项目(LY17D010010)；湖州市公益性应用研究项目(2017GY16) |
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| Effects of water management in lightly Cd-polluted rice fields on Cd accumulation in rice plant and cadmium bioavailability |
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Geying,MA Jin-chuan,ZOU Ping,et al
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1.School of Environmental and Resource Sciences, Zhejiang A＆F University;2.Institute of Environment, Resource, Soil and Fertilizer, Zhejiang Academy of Agricultural Sciences;3.Agriculture and Rural Affairs Bureau of Changxing County;4.Agriculture and Rural Affairs Bureau, Liandu District, Lishui City;5.Agricultural Technology Extension Center of Keqiao District, Shaoxing City
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| Abstract: |
| 【Objective】In order to study the effect of water management in lightly cadmium(Cd)-polluted rice fields on the accumulation of Cd in rice plant and soil cadmium bioavailability, 【Method】a pot experiment was conducted，including 7 treatments: Long-term moist irrigation at the whole growth stage of rice (CK)，flooding at the whole growth stage of rice (T1), flooding from stem elongation(jointing)(T2), panicle initiation to booting (T3), heading and flowering (T4), milk grain (T5) and dough grain (T6) stages. All the treatments were drained for a week before harvest. The differences of Cd accumulation in different rice organs and changes in the redox potential of soil and water-soluble Cd concentration in rhizosphere soil solution were investigated. 【Result】Correlation analysis showed that the redox potential and water-soluble Cd of soil solution had extremely significantly positive correlation (p<0.01). After flooding, the redox potential of the soil decreased significantly，and the reduction of the soil was enhanced. The longer the flooding time, the lower the redox potential, T1 treatment could drop to -159.78 mV at the lowest, the water-soluble Cd in the rhizosphere soil solution also dropped rapidly after flooding, T3 treatment reduced by the most, which was 78.2%. The results showed that the cadmium concentration in rice unpolished under different water management treatments did not exceed the limit value specified in the national food safety standard (GB2762-2017). Compared with CK treatment, T1 treatment reduced Cd concentration in rice by 76.9%, while rice yield was significantly reduced by 19.2%; T6 treatment significantly inhibited the transfer of Cd from roots to above-ground parts of rice, increasing the proportion of Cd mass in roots by 15.2%; T6 treatment reduced the accumulation of Cd mass in rice stems by 13.0%; flooding inhibited the transfer of Cd from leaves to rice grain parts to reduce the accumulation of Cd in rice grain, compared with CK treatment, T5 treatment increased the proportion of Cd mass in leaves by 5.0% while T3 treatment reduced the proportion of Cd mass in grain by 4.3%.【Conclusion】Taking rice yield, rice Cd concentration and field practices into consideration, the recommended water management for lightly Cd-contaminated rice fields was flooding from heading and flowering stage to one week before rice harvest. |
| Key words: water management; rice growth stage; cadmium; redox potential; soil pore water; water-soluble Cd |
