徐洋洋,张兴,左西宇,等. 再生水灌溉对土壤表层大孔隙的影响[J]. 农业工程学报,2023,39(23):113-122. DOI: 10.11975/j.issn.1002-6819.202305030
    引用本文: 徐洋洋,张兴,左西宇,等. 再生水灌溉对土壤表层大孔隙的影响[J]. 农业工程学报,2023,39(23):113-122. DOI: 10.11975/j.issn.1002-6819.202305030
    XU Yangyang, ZHANG Xing, ZUO Xiyu, et al. Effects of reclaimed water irrigation with different water quality on surface soil macro-pores[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2023, 39(23): 113-122. DOI: 10.11975/j.issn.1002-6819.202305030
    Citation: XU Yangyang, ZHANG Xing, ZUO Xiyu, et al. Effects of reclaimed water irrigation with different water quality on surface soil macro-pores[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2023, 39(23): 113-122. DOI: 10.11975/j.issn.1002-6819.202305030

    再生水灌溉对土壤表层大孔隙的影响

    Effects of reclaimed water irrigation with different water quality on surface soil macro-pores

    • 摘要: 再生水是农业灌溉重要的水资源,但作为灌溉用水,因其所富含的营养物质含量和有害物质浓度不同,其对土壤基本物理性质及土壤内部孔隙的影响也存在一定差异,为探明不同水质再生水灌溉下土壤的退化情况,该研究进行了为期1.5a的室外大田灌溉试验,对比4种不同水质(W1:预处理后的生活污水,W2:再生水1,W3:再生水2,W4:自来水)灌溉后土壤的多项基本理化性质的变化情况,包括:pH值、电导率(electrical conductivity,EC)、钠吸附比(sodium adsorption ratio, SAR)及土壤大孔隙和大孔隙结构等。结果表明:1)再生水灌溉1.5a后与淡水灌溉相比,土壤SAR和Na+含量等理化指标均有一定提高,但除SAR及pH值指标有显著提高外,其他指标变化差异并不显著(P<0.05)不同水质再生水短期灌溉均不会造成表层土壤盐碱化。2)再生水灌溉后土壤的总孔隙度变化并不显著,但不同水质再生水灌溉显著增加了表层土壤的大孔隙度和大孔隙连通性(P<0.05),较W4处理,W1、W2和W3处理的大孔隙度(等效孔隙直径D>50 μm)分别增加了120.76%、131.23%和49.69%,连通孔隙占比和连通性指数也均有所增加,但再生水灌溉也显著堵塞土壤内微小孔隙,进而影响土壤水力性质。3)土壤孔隙网络模型结果表明,再生水灌溉后土壤连通性出现了明显改善,孔隙间的连接通道数量显著提高,孔隙网络发育更加复杂,土壤透气性有所增强。综上所述,短期再生水灌溉并不会导致土壤的严重退化,但从长远灌溉发展的角度看,W1水质处理对土壤是有害的,而适当的调低水质标准,对土壤的负面影响并不显著,甚至在一定程度上改善了土壤的通气性。

       

      Abstract: Reclaimed water plays a crucial role in the water resource of agricultural irrigation. Reclaimed water is the high demands for the sustainable water usage in the field. A comprehensive analysis is also required to elucidate the relationship between reclaimed water and soil dynamics in the short- and long-term implications. However, there are great variations in the physical properties and internal pores within soil during irrigation, due to the different concentrations of nutrients and harmful substances. Previous exploration has been focused mainly on the impacts of reclaimed water on soil health and structure merit. In this study, a 1.5-year outdoor experiment of field irrigation was conducted to explore the degradation of soil under reclaimed water irrigation with different water quality. The surface soil of 0-20 cm depth was set as the focus layer of soil after water irrigation, in order to constitute the primary rooting zone for the major crops, such as winter wheat and summer maize. A systematic investigation was then performed on the structure parameters of soil pores in the surface soil layer (0-20 cm). The soil's physical and chemical properties were compared (pH: potential of hydrogen, EC: electrical conductivity, SAR: sodium adsorption ratio, soil macropore, and macropore structure) after irrigation with the reclaimed water of different water quality (W1: pretreated domestic sewage, W2: reclaimed water 1, W3: reclaimed water 2, and W4: tap water). The results showed that: 1) The physical and chemical indexes (such as SAR and Na+ content) in soil increased after 1.5 years of reclaimed water irrigation, compared with the fresh water. But the SAR and pH indicators were significantly improved, whereas, there was no change in the rest. No salinization of surface soil was found in the short-term irrigation of reclaimed water with different water quality. 2) The total porosity of soil remained constant (P<0.05) after reclaimed water irrigation. The macro-porosity and macropore connectivity (equivalent pore diameter D>50 μm) of surface soil was improved by 120.76%,131.23% and 49.69%, respectively, in the W1, W2, and W3 treatment, compared with the W4. The proportion of connected pores and connectivity index also increased. But reclaimed water irrigation significantly blocked the tiny pores in the soil, leading to the soil's hydraulic properties. 3) The soil connectivity was improved after reclaimed water irrigation. The number of connecting channels between pores also increased for the more complex pore network and the soil aeration. In summary, the short-term reclaimed water irrigation cannot lead to the serious soil degradation. However W1 treatment was harmful to the soil from the perspective of long-term irrigation. The soil aeration was then improved to reduce the standards of water quality for a better impact on the soil.

       

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