| 引用本文: | 周靖,栾雅珺,王流通, 等.不同水肥管理稻田土壤铬生物有效性及吸收富集特征[J].灌溉排水学报,2022,41(2):35-43. |
| ZHOU Jing,LUAN Yajun,WANG Liutong, et al..不同水肥管理稻田土壤铬生物有效性及吸收富集特征[J].灌溉排水学报,2022,41(2):35-43. |
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| 摘要: |
| 【目的】探究不同水肥管理对土壤铬生物有效性的影响及水稻吸收富集特征。【方法】试验地为8 a长期定位水肥管理水稻田，灌溉处理设常规灌溉（F）、控制灌溉（C）2种灌溉模式，施肥处理设为施用常规化肥（F）、有机肥（OF）2种施肥模式，分析了不同水肥管理下稻田土壤pH值、土壤铬量及形态分布、水稻根系和稻谷铬量的差异。【结果】①与常规灌溉处理和常规施肥处理相比，控制灌溉处理和有机肥处理均显著降低了土壤pH值。②与FF处理相比，COF处理增加了土壤可交换态、可还原态和可氧化态铬量和比例，各形态铬量分别增加了54.31%、43.06%和39.33%；减少了残渣态铬量和比例，残渣态铬量减少了2.84%；提高了重金属铬从根到稻谷的转运系数；增加了水稻植株根部和稻谷铬量，分别较FF处理增加了46.31%和59.43%。③在相同灌溉条件下，不同施肥处理土壤pH值和可交换态、可还原态铬量显著负相关；而在相同施肥条件下，不同灌溉处理间土壤pH值和可交换态、可还原态铬量之间不存在明显相关性。【结论】对比常规肥，施用有机肥给节水灌溉稻田带入了外源重金属铬，并显著增强了土壤铬生物有效性，促进了水稻植株吸收富集铬，威胁水稻安全生产；对比常规灌溉，控制灌溉对土壤铬生物有效性影响不大。 |
| 关键词: 灌溉；有机肥；稻田；铬；生物有效性 |
| DOI：10.13522/j.cnki.ggps.2021400 |
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| The Impact of Irrigation and Fertilization on Bioavailability of Chromium and Its Absorption and Enrichment in Paddy Rice |
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ZHOU Jing, LUAN Yajun, WANG Liutong, et al.
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1. College of Agricultural Science and Engineering, Hohai University, Nanjing 210098, China;
2. State Key Laboratory of Hydrology-water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China;
3.Taihu Basin Authority of Ministry of Water Resources, Shanghai 200434, China
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| Abstract: |
| 【Background and objective】Sewage irrigation and extensive use of chemical fertilizers have resulted in soil pollution by heavy metals in many countries including China, threatening food safety and security. Understanding the impact of agronomic managements on bioavailability of heavy metals and their adsorption by crops is hence important to mitigate their impact on food production. Taking chromium in paddy soil as an example, this paper investigated how irrigation and fertigation combined to mediate its uptake by paddy rice.【Method】The experiment was conducted on a site that has been contaminated by chromium for eight years. We compared two irrigations: conventional irrigation (F) and controlled irrigation (C). In each irrigation, there were two fertilization treatments: conventional chemical fertilization (F) and organic fertilization (OF). In each treatment, we measured pH and chromium in different forms in the soil, as well as chromium content in roots, shoots and rice grains.【Result】Compared with conventional irrigation and chemical fertilization, controlled irrigation and organic fertilization significantly reduced soil pH. Compared with F+F, C+OF increased the content and proportion of exchangeable, reducible and oxidizable chromium in soil by 54.31%, 43.06%, and 39.33%, respectively, while reducing the content and proportion of residual chromium by 2.84%. Improved fertilization and irrigation also enhanced the transfer coefficient of chromium from below-ground to above-ground, and increased chromium content in the roots and grain by 46.31% and 59.43% respectively, compared to F+F. Under the same irrigation, soil pH was negatively correlated with the exchangeable and reducible chromium content, and the difference in the impact between different fertilizations was significant. Under the same fertilization, different irrigations did not show noticeable impact on the correlation between soil pH and exchangeable and reducible chromium.【Conclusion】Compared with conventional fertilization, organic fertilization brought exogenous chromium into the soil thereby significantly enhancing its bioavailability and absorption and enrichment by the rice. Compared with conventional irrigation, controlled irrigation did not show noticeable effect on chromium bioavailability. |
| Key words: irrigation; organic fertilization; paddy field; chromium; bioavailability |
