Journal of Soil Science and Plant Nutrition ( IF 3.9 ) Pub Date : 2021-09-07 , DOI: 10.1007/s42729-021-00601-1 Linfeng Li 1, 2, 3 , YiChun Li 1, 2, 3 , Yanhong Wang 1, 2, 3 , Mingdeng Tang 1, 2, 3 , Shaoying Ai 1, 2, 3
Combining different technologies to improve remediation efficiency is essential for remediating metal-contaminated farmland soils. In situ immobilization and irrigation management have been widely used in the Cd-polluted paddies. However, the interaction between soil amendment and irrigation management and its influence on Cd transportation in the root-soil system is poorly understood. A pot experiment was conducted to investigate the effects of a novel silicon-rich amendment (SR) on Cd behavior in the soil, the radial oxygen loss (ROL) and formation of Fe/Mn plaque on the root surface, and the accumulation of elements in the rice under continuous flooding (CF) and alternate wetting and drying (AWD) irrigations. SR addition under CF irrigation had the lowest Cd concentration in brown rice (0.18 ± 0.04 mg kg−1) among treatments. The CF + SR treatment induced lower Eh and higher pH and led to more exchangeable Cd converted into Fe/Mn oxides and residual fractions, reducing Cd bioavailability in the soil. Moreover, CF irrigation induced Fe/Mn plaque formation, and SR addition further promoted the Fe/Mn plaque formation by enhancing ROL from the roots, strengthening the barrier effects of plaques for Cd uptaking. Besides, the CF + SR application increased the Fe and Ca concentrations in the rice roots to compete with Cd for uptaking and translocation and suppressed Cd accumulation in rice. The findings suggested that the simultaneous use of Si-rich amendment with continuous flooding irrigation is a potentially highly efficient remediation strategy for safe rice production in Cd-polluted paddies.
中文翻译:
富硅修正结合灌溉管理减少糙米中镉的积累
结合不同技术提高修复效率对于修复受金属污染的农田土壤至关重要。就地固定和灌溉管理已广泛应用于镉污染的稻田。然而,土壤改良剂和灌溉管理之间的相互作用及其对根 - 土壤系统中 Cd 运输的影响知之甚少。盆栽试验研究了新型富硅改良剂 (SR) 对土壤中 Cd 行为、径向氧损失 (ROL) 和根表面 Fe/Mn 斑块形成以及元素积累的影响在连续洪水 (CF) 和交替干湿 (AWD) 灌溉下的水稻中。CF 灌溉下的 SR 添加在糙米中具有最低的 Cd 浓度(0.18 ± 0.04 mg kg -1) 之间的治疗。CF + SR 处理导致较低的 Eh 和较高的 pH 值,并导致更多可交换的 Cd 转化为 Fe/Mn 氧化物和残留部分,从而降低了土壤中 Cd 的生物有效性。此外,CF灌溉诱导了Fe/Mn斑块的形成,SR添加通过增强根部的ROL,加强斑块对Cd吸收的屏障作用,进一步促进了Fe/Mn斑块的形成。此外,CF + SR 施用增加了水稻根部的 Fe 和 Ca 浓度,与 Cd 竞争吸收和转运,抑制了水稻中 Cd 的积累。研究结果表明,同时使用富硅改良剂和连续漫灌是一种潜在的高效修复策略,可在 Cd 污染的稻田中安全水稻生产。