氨化秸秆还田对土壤孔隙结构的影响

【目的】土壤孔隙性质是土壤结构性的反映,直接影响着土壤的肥力和水分有效性。定量研究氨化秸秆还田对土壤不同大小等级孔隙数量和孔隙分布的影响,可以为土壤培肥提供科学依据。【方法】采用室内试验方法,设置氨化秸秆加入量为土壤总质量的 0(CK)、 0.384%(S1)、 0.575%(S2)、 0.767%(S3)4个处理,室内培养。在培养0、60、120和180 d,取样测定土壤水分特征曲线(SWRC)数据,利用双指数土壤水分特征曲线模型(DE模型,Double-exponential water retention equation),分析氨化秸秆对土壤剩余孔隙、基质孔隙和结构孔隙的影响; 基于DE模型的微分函数,探究不同氨化秸秆处理对土壤孔隙分布的影响。【结果】不同处理的土壤水分特征曲线SWRC实测值和DE模型模拟值之间的均方根误差介于0.0036和0.0041 cm3/cm3之间,R2介于0.998和0.999之间,土壤含水量模拟值和实测值非常接近1 ∶1,表明DE模型可以准确反映添加氨化秸秆后土壤含水量随吸力的变化规律,较准确地估算土壤不同大小等级孔隙数量变化。培养120 d内,氨化秸秆对土壤剩余孔隙、基质孔隙和结构孔隙影响不显著; 培养180 d时,各处理土壤结构孔隙度表现出随着氨化秸秆添加量的增加而增加的趋势; 此时S3对土壤剩余孔隙影响不显著,显著减小了土壤的基质孔隙度(P0.05),极显著地增加了土壤的结构孔隙度(P 0.01)。在孔隙分布中,氨化秸秆促进了土壤已有孔隙向较大孔隙的发育,显著增加了土壤结构孔隙分布数量; 随着氨化秸秆添加量的增加,土壤结构孔隙的分布数量越大,且峰值出现的越早。氨化秸秆增加了土壤中有机质含量; 土壤结构孔隙和总孔隙均与有机质含量呈显著的正相关关系(P 0.05); 有机质可以黏结团聚土壤的矿物颗粒,有效地促进了土壤结构孔隙的发育; 氨化秸秆对土壤孔隙的影响随着时间的进行越来越明显。【结论】氨化秸秆增加了土壤中有机质含量,促进了土壤孔隙结构的发育,增加了土壤的结构孔隙度和总孔隙度,这对改良和培肥土壤、改善土壤耕性具有重要意义。     

Descriptive field symbols for inped soil macropores

Abstract

A short hand notation for depicting inped soil macropores is presented. By utilizing symbols for macropore diameter, facial shape, pore length, inped shape and pore orientation; it is possible to quickly portray inped field macropores. Circles, ellipses, and triangles of differing dimensions are used to symbolize round, elliptical, and irregular facial shaped pores of different diameters. The pore length and orientation are symbolized by line length and line direction. The inped shapes (spherical, tubular, and elongated) are respectively represented by one line, two parallel lines, or three parallel lines within or intersecting the pore shape symbols. Field application of this methodology saves time and is valuable when numerous inped pores need to be depicted.     

基于土壤导气率的燥红土孔隙结构及弯曲连通性研究

土壤气体传输高度依赖土壤孔隙结构,导气率的获取简单、快速、高效,且对土壤结构破坏小,利用PL-300土壤空气传导性测量系统分别对不同含水率、不同容重条件下的原状土与扰动土进行导气率测量,展开针对土壤孔隙结构与弯曲连通性的讨论。结果表明:(1)原状土样本孔隙弯曲连通性随气相饱和度增加而增加的程度较扰动土样本显著,两者相对导气率与饱和度的关系曲线变化走势差异不大,表明即便饱和度一样的条件下,孔隙弯曲连通程度仍然不同;(2)原状土导气率依赖于大孔隙的存在,扰动土导气率不仅依赖于孔隙连通的程度,还取决于孔隙弯曲程度。基于土壤导气率对土壤孔隙结构及弯曲连通性的讨论,在建立气体传输模型时应考虑孔隙尺寸分布对导气率的影响,就原状土与扰动土不同的弯曲连通系数加以区分与讨论,为进一步揭示土壤气体传输的内在机制提供参考。     

Verformungsverhalten künstlicher Makroporen unter variierenden Druck‐ und Bodenfeuchtebedingungen

Structural deformation of artificial macropores under varying load and soil moisture In the present study, the stability and deformation behavior of artificial macropores under varying load and soil moisture levels was investigated by means of X‐ray computed tomography (CT). The results should be a reference for similar studies on soil samples from field trials. The soil tested was a well structured humic silt loam with a bulk density of 1 g cm^—3. Round‐shaped pores of vertical and 45 degree angle orientation were drilled into the samples with a plastic needle (∅︁ 5 mm). These samples were compacted in an uniaxial compression device at four different moisture levels and four pressure stages each. Stepwise CT imaging and its 3‐dimensional reconstruction enabled us to study systematically the mode and intensity of pore deformation. As a result four different deformation stages could be identified in dependence from load, soil moisture, and pore orientation. The deformation stage ”︁stable” was characterized by mostly unaffected pore dimensions and shapes. Increasing load and/or moisture content led to prominent bottle necks within the pores which was named ”︁structure deformation”. Due to the shape and size of these bottle necks it seems to be most likely that still intact aggregates were moved into the inner pore space, reducing the mean cross sectional areas. The deformation stage ”︁total deformation” appeared with further increase of load and/or moisture. The aggregated structure disappeared while the inner roughness of the pores became smoother again. This represents a viscoplastic deformation. Cross sectional areas, pore lengths, and volumes significantly decreased. The stage ”︁extinction” was finally reached at water contents around the liquid limit, where the pore structure was completely lost, at least on CT resolution level. The deformation stages could be attributed to load stages depending from pore orientation. Unexpectedly, all pores kept their originally round shape over all stages until extinction.     

生物炭对沙质土水分蒸发和导水率的影响

Biochar, as a kind of soil amendment, has important effects on soil water retention. In this research, 4 different kinds of biochars were used to investigate the influences of biochar addition on hydraulic properties and water evaporation in a sandy soil from Hebei Province, China. Biochar had strong absorption ability in the sandy soil. The ratio of water content in the biochar to that in the sandy soil was less than the corresponding ratio of porosity. Because of the different hydraulic properties between the sandy soil and the biochar, the saturated hydraulic conductivity of the sandy soil gradually decreased with the increasing biochar addition. The biochar with larger pore volume and average pore diameter had better water retention. More water was retained in the sandy soils when the biochar was added in a single layer, but not when the biochar was uniformly mixed with soil. Particle size of the added biochar had a significant influence on the hydraulic properties of the mixture of sand and biochar. Grinding the biochar into powder destroyed the pore structure, which simultaneously reduced the water absorption ability and hydraulic conductivity of the biochar. For this reason, adding biochar powder to the sandy soil would not decrease the water evaporation loss of the soil itself.     

Spatial variability of water retention parameters and saturated hydraulic conductivity in a calcareous Inceptisols (Khuzestan province of Iran) under sugarcane cropping

The objective of this study was to quantify inherent spatial variability and spatial cross-correlation of the van Genuchten retention parameters and saturated hydraulic conductivity (K_s) of surface and subsurface layers in a calcareous Inceptisols (Khuzestan province, Iran) under sugarcane cropping. Measurements were performed on 100-cm³ undisturbed soil cores collected at 94 locations along a 30-m-long transect with horizontal sampling distance intervals of 0.3 and 1 m at soil depths of 0–40 and 40–80 cm, respectively. Spatial variability was investigated using conventional statistics and geostatistical techniques. Coefficient of variation (CV) varied from 8.2% (for shape parameter, n at 40–80 cm depth) to 256.7% (for K_s at 0–40 cm depth). The n parameter and saturated water content, θ_s, showed a small-scale spatial heterogeneity with a maximum CV of 11.3% for the first depth and 9.2% for the second depth. Most of the hydraulic parameters at both depths showed a spatial structure and convex experimental semivariograms with dominant spherical models with the influence range of 3.2–41 m. In most cases, the extent of spatial correlation scales of cross-semivariograms for pairs of cross-correlated hydraulic variables was found to be different with reference to those relating to the direct semivariograms of correlated variables.     

微波真空冷冻干燥时怀山药的微CT孔道分布

局部温度过高的问题限制了微波真空冷冻干燥（microwave freeze drying,MFD）技术在果蔬干燥中的广泛应用。发展传热传质理论是解决MFD局部温度过高问题的根本途径。数值模拟是研究传热传质机理的重要方法,并有望解决MFD中局部温度过高的问题。利用详细的孔径和孔隙分布建立结构模型对数值模拟至关重要。该研究以怀山药为样品,利用微CT（X-ray micro-computed tomography）技术分析不同干燥仓压力（100、200、300 Pa）和微波加载量（0.5、1.0、1.5、2.0 W/g）时孔隙和孔隙分布的变化。结果表明,干燥仓内的低压环境更倾向于形成小孔隙,干燥仓内压力的变化对外层的孔隙大小和分布无明显影响,但对内层的孔隙大小和分布有明显影响。微波加载量对内、外层的孔隙大小和分布均有显著影响。研究结果将为解决MFD中局部温度过高问题的数值计算研究提供试验支持。     

坡面径流泥沙计算中需解决的认识问题

基于土壤侵蚀规律的研究特点，特别是坡面水蚀动力过程的研究需要，对以往传统的坡面径流泥沙计算方法进行的分析发现，传统的计算方法误将土壤中的孔隙水当作坡面径流，从而导致误将坡面的侵蚀对象及搬运物当作坡面的侵蚀动力，为进一步分析坡面水蚀动力机制带来了困难。在上述分析基础之上，提出了坡面径流泥沙的计算方法，并与传统方法进行了计算误差分析。结果表明，两种方法的计算误差随含沙量的增加而增大。当土壤容重为１．２ｔ／ｍ３时，若含沙量达３００ｋｇ／ｍ３，径流量计算误差大于２０％，含沙量计算误差接近２０％。     

松散土样和填装土柱及紧实程度对土壤有机碳矿化的影响

土壤有机碳（SOC）矿化一般通过培养松散土样来测定,但是松散土样与原状土的结构存在很大差异,二者之间SOC矿化的关系尚不明确;通过填装土柱可以获得接近田间状态的土壤样品,但填装的紧实程度会改变土壤孔隙结构,因此可能影响SOC矿化。本研究首先以施用不同量有机肥的红壤为研究对象,设置松散土样和填装土柱两个处理,采用室内培养法比较二者之间SOC矿化的差异;然后选择其中一种土壤填装土柱,设置四个紧实程度处理,分别为1.1（BD1.1）、1.3（BD1.3）、1.5（BD1.5）和1.7 g?cm-3（BD1.7）,利用X射线显微CT（Computed Tomography, CT）成像技术分析土壤孔隙结构,分析紧实程度对土壤孔隙结构及SOC矿化的影响。结果表明,松散土样与填装土柱的SOC矿化量有显著差异,培养结束时（第57天）,松散土样的有机碳累积矿化量约是填装土柱的4倍。紧实程度增加较大程度地降低了土壤的总孔隙度和大孔隙度,降低比例分别为12.9% ~ 17.4%和18.7% ~ 88.5%;并且使充气孔隙度从63.6%下降到了8.2%,而充水孔隙度从36.4%增加到了91.8%。填装土柱的SOC矿化量随紧实程度增加呈先增加后降低的趋势,培养结束时（第28天）,BD1.5的SOC矿化量最高。回归分析的结果表明,SOC矿化量与总孔隙度、大孔隙度（>16 μm）、充水孔隙度（Water-filled pore space, WFPS）或充气孔隙度（Air-filled pore space, AFPS）之间存在显著的非线性关系。当总孔隙度或大孔隙度低于46%或3.7%时,SOC矿化量随孔隙度增加而增加;反之,SOC矿化量随孔隙度增加而降低。SOC矿化量与WFPS或APFS之间的关系呈现出类似的规律,当WFPS为66%或AFPS为34%时,SOC矿化量最高。以上结果说明,通过培养松散土样测定SOC矿化将会高估田间SOC的矿化潜力;紧实程度的变化会改变土壤的孔隙结构进而影响填装土柱的SOC矿化;SOC矿化量与孔隙度之间存在显著的非线性关系。     

地貌演替序列特征对土壤生物群动态的季节效应

Numerous studies have been devoted to the physical-chemical weathering processes leading to the creation of unique soil formations having their own history that induce soil-biotic diversity. However, the extent to which unique geomorphic formations influence soil biotic seasonal variation is not clear. Our aim was to define seasonal variations of soil biota in soils of different-aged terraces of the Makhtesh Ramon anticline erosional cirque in southern Israel. The strong effect of Makhtesh Ramon (Ramon Crater) erosional fluvial terrace age initiated by climatic changes during the Late Pleistocene–Early Holocene period on seasonal variations in both soil properties and the abundance and composition of soil biota were demonstrated. However, age dependence was not constant and values for observed soil properties and microbial activity were negligible between younger and older terraces for certain seasons, while free-living nematodes along with bacteria-feeding group were strongly dependent on the geomorphic features of the ages throughout the study period.     

Effects of porous clay ceramic rates on aeration porosity characteristics in a structurally degraded soil under greenhouse vegetable production

Soil structure degradation in greenhouse vegetable fields reduces vegetable production. Increasing aeration porosity is the key to ameliorating soil structure degradation. Thus, we tested the effect of a porous material, porous clay ceramic(PLC), on the amelioration of soil structure degradation under greenhouse vegetable production. A 6-month pot experiment was conducted with four PLC application levels based on volume, i.e., 0%(control), 5%(1 P), 10%(2 P), and15%(3 P) using Brassica chinensis as the test plant. At the end of the experiment, soil columns were sampled, and the aeration pore network was reconstructed using X-ray computed tomography(CT). The degree of anisotropy(DA), fractal dimension(FD), connectivity, aeration porosity, pores distribution, and shape of soil aeration pores and plant biomass were determined. The DA, FD, and connectivity did not significantly differ as the PLC application rate increased.Nonetheless, aeration porosity significantly linearly increased. The efficiency of PLC at enhancing soil aeration porosity was 0.18% per Mg ha~(-1). The increase in aeration porosity was mainly due to the increase in pores 2 000 μm, which was characterized by irregular pores. Changes in aeration porosity enhanced the production of B. chinensis. The efficiency of PLC at increasing the plant fresh weight was 0.60%, 3.06%, and 2.12% per 1% application rate of PLC for the 1 P, 2 P, and 3 P treatments, respectively. These results indicated that PLC is a highly efficient soil amendment that improves soil structure degradation by improving soil aeration under greenhouse conditions. Based on vegetable biomass, a 10% application rate of PLC was recommended.     

Nitrate Evolution in Soil,Leaching Water,and Lettuce Plant Crops using Different Fertilization Strategies

The aim of this study was to investigate the effects of different fertilizing strategies applied during three successive cycles on lettuce growth and the nitrate evolution in the soil, leaching water, and the lettuce plant itself. Four fertilization treatments were compared: integrated production fertilization (IP), organic fertilization (ORG), slow-release N fertilizers (SRF), and plant-associative bacteria (PAB). The nitrate content of the pore water and leachate decreased toward harvesting time in each crop cycle. The accumulation of residual nitrates in the soil decreased in each successive cycle in all treatments. The greatest lettuce head weight was achieved by ORG and SRF in the first cycle and by IP in the third cycle; IP and SRF produced the greatest nitrate content in lettuce leaves, especially in the second and third cycles. The nitrate content of leaves fell in the last cycle, as nitrate levels in soil and in leaching fell in all treatments.     

Size Distribution of Dispersed and Aggregated Particles and of Soil Pores in 12 Danish Soils

Abstract

Soil texture, aggregates in different size classes and water retention at several water potentials were measured in the top layers of 12 Danish soils. Size frequency curves of dispersed and aggregated soil particles and of soil pores were calculated using numerical differentiation of sum curves, which were obtained from measured data through interpolation procedures. Soils which originated from water sediments had narrow peaks with approximately lognormal distribution of dispersed soil particles and of soil pores, reflecting the sorting action of the water. Moraine soils appeared to have broad and flat frequency curves of dispersed soil particles, some of which were bimodal or skewed. These soils exhibited a typical bimodal size distribution of soil pores. Degree of aggregation was determined primarily by the soil content of clay, 10% or more creating stable macroaggregates of 2–6 mm diameter. A comparison of the frequency curves for soil pore size to a generalized four-parameter mathematical expression relating matric potential and volumetric water content revealed that the model fitted the empirical data reasonably well for the well-sorted water-sedimented soils, while in the case of the bimodal pore size soils a deviation of differing magnitude was observed. From the investigation it is recommended that in most cases, quantities of particles and pores in soil should be related to size with frequency rather than cumulative expressions.     

孔隙空间对聚苯乙烯胶体滞留与释放的影响

为加深孔隙空间对胶体运移影响的认识,在不同pH与离子强度下,研究了胶体在经酸洗或水洗后的玻璃珠或石英砂中的迁移行为。结果表明:粒径相同的玻璃珠与石英砂(0.45~0.60mm)相比,形状一致的玻璃珠形成的孔隙空间(孔隙率0.38)小于石英砂(0.45)。酸洗与水洗后的玻璃珠表面成分变化不大(0~0.6%),经酸洗的介质后能提供更多有利吸附位点。在高pH(10)环境下,石英砂经酸洗或水洗后,胶体滞留量增大(72.1%和69.2%)。提高溶液pH到10后出现的胶体吸附增加,是颗粒接触点、非流动区或低流速区和涡流区滞留等孔隙空间滞留机制引起的,用DLVO理论无法解释。在离子强度为0.001mol/L或0.05mol/L环境下,酸洗石英砂中胶体滞留量比酸洗玻璃珠的分别高16.3%和28.0%,表明介质孔隙空间增大可加强颗粒接触点、非流动区或低流速区和涡流区滞留,然而优先流能够削弱孔隙空间滞留机制对胶体的滞留。此外,超纯水解吸时仅使少量胶体(3.9%)从玻璃珠与石英砂介质的孔隙涡流区中解吸出来,表明涡流区对胶体的保留不是胶体滞留在介质中的主要机制。     

Conservation Agriculture Had a Poor Impact on the Soil Porosity of Veneto Low‐lying Plain Silty Soils after a 5‐year Transition Period

Conservation agriculture practices have been proposed as a set of techniques for improving soil structure properties and related ecosystem services. This study compared conservation agriculture (CA) practices (no‐tillage, cover crop and residue retention) and conventional intensive tillage system in order to evaluate their effects on total porosity, pore size distribution, pore architecture and morphology. The experiment was set up in 2010 on four farms of the low‐lying Veneto Region plain characterized by silty soils. Almost hundred soil samples were collected in 2015 at four depths down to 50‐cm layer and investigated for porosity from micrometre (0·0074 μm) to macrometre (2·5 mm) by coupling mercury intrusion porosimetry and X‐ray computed microtomography (μCT). Indices of soil morphology and architecture were derived by analysing 3D images and mercury intrusion porosimetry pore size curves. Results suggested that silty soils of Veneto plain are microstructured because much (82%) of the porosity ranged between 0·0074 and 30 μm. CA practices positively influenced the ultramicroporosity class (0·1–5 μm) (1·86E‐01 vs 1·67E‐01 μm³ μm⁻³) that is strictly linked to soil organic carbon stabilization while no effects were observed in X‐ray μCT porosity domain (> 26 μm). Silty soils of Veneto plain showed a slow reaction to CA because of the poor aggregate stability and low soil organic carbon. However, the positive response of the ultramicropore fraction indicates that a virtuous cycle was initiated between soil organic carbon and porosity, hopefully leading to well‐developed macropore systems and, in turn, enhanced soil functions and ecosystem services. Copyright © 2017 John Wiley & Sons, Ltd.     

Evaluation of Differential Pore-Volume Distribution (DPVD) Patterns of Porous Clinoptilolite Fractions

Analysis of differential pore-volume distribution (DPVD) patterns of a commercial Clinoptilolite has been conducted experimentally using an analyzer by measuring the N₂ adsorption isotherm. The commercial material was fractionated by sieving through sequential sieves: <125 µ (Z8; fine), 125–250 µ (Z9; medium), and >250 µ (Z10; coarse). The DPVD of the fractions were calculated from the hysteresis loop according to the adsorption and desorption curves of Dollimore-Heal (DH) model. The adsorption cycle had produced dissimilar differential pore volume distribution patterns. For the 10-nm pore width, fine and medium fractions had a maximum pore volume up to 0.0016 cm³/g nm, while the coarse fraction had a little greater value up to 0.002 cm³/g nm. Moreover, the medium fraction had too many hills and valleys in the DPVD. However, the desorption cycle–based DH analysis did not show any marked variation in the DPVD pattern.     

Simple and Rapid Laboratory Method for Rewetting Dry Soil for Incubations

Soil microbial activity is greatly affected by soil water content. Determining the appropriate moisture content to rewet soils that have been dried in preparation for laboratory incubations to determine microbial activity can be laborious and time-consuming. The most common methods used achieve sufficient moisture content for peak microbial respiration are gravimetric water content, soil matric potential, or percentage of water-filled pore space (WFPS). Alternatively, a fast, simple, and accurate way to ensure that a given soil receives the appropriate amount of water for peak soil microbial respiration is to rely on natural capillary action for rewetting the dry soil. The capillary method is related to the gravimetric method for water uptake and has a strong correlation with WFPS. A microbial respiration test was conducted to compare rewetting methods. The 24-h carbon dioxide (CO₂) / carbon (C) results were very similar and strongly correlated using the gravimetric method and the capillary method for rewetting dried soil.     

Effects of organic carbon and clay contents on structure-related properties of arable soils with high clay content

Understanding of factors governing soil structural features is necessary for managing key processes affecting crop productivity and environmental impacts of agriculture, for example, soil water balance, aeration, and root penetration. Organic matter is known to act as a major binding agent in soil aggregation and thus constitutes a central pillar in soil structure formation. However, knowledge of the structural role of organic matter or carbon (OC) in soils highly rich in clay-sized particles (<0.002 mm) is limited. In this study, the effects of clay and OC contents on aggregate stability, water holding capacity, near-saturated hydraulic conductivity, total porosity, and pore size distribution were assessed in cultivated fields with high clay content located in private crop production farms in southern Finland. Significant positive correlations were found between OC content and proportion of water stable aggregates and specific pore sizes from the range of 30 μm up to 1 mm diameter determined by image analysis. Porosities on a smaller size range derived from water retention measurements likewise showed a positive correlation with OC in <0.2 μm sizes. On the range of 0.2–1 μm, a negative relationship was observed, which induced a negative effect of OC on soil plant available water reserves. In line with the positive correlation between OC and larger soil pores, free water, representing the amount of water that can be drained by gravity, exhibited a positive relationship with OC suggesting that OC content can enhance aeration of soils with high clay content. Compared to OC, clay content tended to have an adverse effect on soil structural properties. Clay correlated negatively with pores larger than 30 μm, free water content, and extrapolated field saturated hydraulic conductivity. Further, our imaging results showed how saturated hydraulic conductivity was controlled by pore morphology, and there was a power law relationship between the conductivity and critical pore diameter. $K\propto d_c^2$ in agreement with the percolation theory. Overall, the structural impacts and hydrological implications of OC and clay in heavy clay soils vary by pore size ranges and their emergent practical impacts are thus not straightforward.     

再生水灌溉对土壤表层大孔隙的影响

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。