Abstract：
Reclaimed water irrigation has emerged as a critical alternative in agricultural regions facing water scarcity. However, soil pollution with microplastics (MPs) greatly increases the exposure risk and toxic effects of reclaimed water contaminations, such as phthalate esters (PAEs). A field experiment consisting of soil column pots evaluated the feasibility of using PAEs-contaminated water to irrigate oats (Avena sativa L.) in drought seasons. Three irrigation regimens based on soil matric potential thresholds (-10 kPa, -30 kPa, -50 kPa) explored the impact of PAE-contaminated water on oat physiology and environmental pollution in soil with and without MPs contamination. The results showed that treating oats at the SMP of -30 kPa boosted shoot biomass by 3.1%-14.0% compared to the drought condition at -50 kPa, and the root biomass of oats was significantly increased. The physiological metrics of oats indicated that irrigation at -50 kPa induced drought stress and oxidative damage in oats, particularly during the milk stage. Different irrigation treatments influenced the accumulation of PAEs in plants, soil, and leachate. The ratios of leachate to irrigation water in -10 kPa treatment with and without MPs addition were 1.18% and 4.48%, respectively, which aggravated the accumulation of pollutants in deep soil layers and may cause groundwater pollution. MPs pollution in soil increased the content of PAEs in the harvested oats and reduced the transport and accumulation of PAEs in deep soil layers (20-50 cm) and leachate. The coupling of PAEs in irrigation water with soil MPs pollution may exacerbate plant damage. However, the damage can be minimized under the scheduled irrigation at -30 kPa which could balance crop yield and potential risks.
摘要：
再生水灌溉已成为面临水资源短缺的农业地区的重要替代方案。然而,微塑料（MPs）的土壤污染大大增加了再生水污染物的暴露风险和毒性作用，如邻苯二甲酸酯(PAEs)。由土壤柱盆组成的田间试验评估了在干旱季节使用受PAEs污染的水灌溉燕麦（AvenasativaL.）的可行性。基于土壤基质电位阈值的三种灌溉方案(-10kPa，-30kPa,-50kPa）探讨了受PAE污染的水对有和没有MPs污染的土壤中燕麦生理和环境污染的影响。结果表明，与-50kPa的干旱条件相比，在-30kPa的SMP条件下处理燕麦可将芽生物量提高3.1％-14.0％，燕麦根系生物量显著增加。燕麦的生理指标表明，在-50kPa下灌溉会引起燕麦的干旱胁迫和氧化损伤，尤其是在牛奶阶段。不同灌溉处理影响PAEs在植物体内的积累,土壤,和渗滤液。在-10kPa处理中，在添加和不添加MPs的情况下，渗滤液与灌溉水的比率分别为1.18％和4.48％，分别,这加剧了污染物在深层土壤中的积累，并可能造成地下水污染。土壤中的MPs污染增加了收获的燕麦中PAEs的含量，并减少了PAEs在深层（20-50cm）和渗滤液中的迁移和积累。灌溉水中PAEs与土壤MPs污染的耦合可能会加剧植物的危害。然而,在-30kPa的预定灌溉下，可以将损害降至最低，这可以平衡作物产量和潜在风险。
