岷江上游森林土壤大孔隙特征及其对水分出流速率的影响

大孔隙是森林土壤中常见的现象 ,对土壤壤中流的产生有重要的影响。但由于大孔隙研究方法的不成熟 ,各种方法得到的大孔隙半径范围并不一致。一般认为田间持水量和饱和含水量之间的土壤孔隙为大孔隙 ,利用水分穿透曲线和 Poiseuille方程研究了岷江上游不同植被下土壤的大孔隙状况 ,这种方法一方面与传统的研究方法相衔接 ,另一方面所得到的大孔隙与土壤水分运动有关 ,反映了土壤大孔隙的研究目的 ,因而是一种相对合理的研究方法。岷江上游几种主要植被下土壤大孔隙半径主要集中于 0 .3～ 2 .4 mm之间 ,平均在 0 .4 8～ 1.17mm之间 ,均值为 0 .84 mm,均方差为 0 .2 2 6 ;且随着剖面的发育表现出上部土层多 ,下部土层少的特点。同时 ,半径在 2 .4～ 1.4 m m之间的特大孔隙较少 ,<1.0 m m的小孔隙较多。大孔隙的平均半径对于水分出流速率有重要的影响 ,特别是半径 >1.4 mm的孔隙数量影响最大 ,虽然其数量仅占大孔隙数量的 5 %以下 ,但决定了稳定出流速率 70 %的变异。大孔隙所占过水断面的最高比例为 2 1.2 2 % ,最低为 2 .6 % ;在大孔隙所占过水断面的比例小于 2 0 %的条件下 ,稳定出流速率随大孔隙的增多而增大     

秦岭火地塘林区土壤大孔隙分布特征及对导水性能的影响

大孔隙广泛分布于森林土壤中,是定量研究与土壤水分运动有关的重要因素,其研究可深化森林涵养水源机理的认识。基于田间持水量到饱和含水量之间的土壤孔隙作为大孔隙的标准,利用土壤水分穿透曲线和Poiseulle方程研究了秦岭火地塘林区森林土壤大孔隙分布特征及其对土壤饱和导水率的影响。结果表明,林区土壤大孔隙当量孔径主要分布在0.3—3.8 mm之间;当量孔径1.5 mm的大孔隙密度较小,其数量仅占大孔隙总数量的5.37%;各当量孔径的大孔隙密度随土层分布基本呈现为上层大、下层小的特点,且垂直分布差异显著,其与有机质含量分布有极显著的相关性。0—60 cm土层大孔隙平均面积比顺序为:针阔混交林油松林落叶阔叶林华山松林。不同当量孔径的大孔隙密度与饱和导水率呈显著正相关关系,当量孔径大于1.5 mm的大孔隙密度决定了饱和导水率84%的变异;大孔隙率平均在1.6%—13.3%之间,当其小于5%时,饱和导水率随着大孔隙率增大而增大。     

Ecosystem wicks: Woodland trees enhance water infiltration in a fragmented agricultural landscape in eastern Australia

Abstract Since European settlement, Eucalyptus box woodlands have been substantially modified by agricultural practices, and in many areas in southern Australia are now restricted to scattered or clumped trees. We report here on a study to examine the impact of trees on water flow (infiltration) in an agricultural landscape with substantial areas of extant native vegetation. We examined infiltration through coarse‐ and fine‐textured soils within four landscape strata, the zones below Eucalyptus melliodora and Callitris glaucophylla canopies, the intertree zone dominated by perennial grasses and a landscape homogenized by cultivation and dominated by annual crops. We measured sorptivity, the early phase of water flow, and steady‐state infiltration with disc permeameters at two supply potentials. These different potentials enabled us to separate infiltration into (i) flow through large (biopores) and small pores and (ii) flow through small pores only where biopores are prevented from conducting water. On the fine‐textured soils, both sorptivity and steady‐state infiltration were significantly greater (approximately fivefold) under the timbered strata compared with the grassy slopes or cultivation. Differences were attributable to the greater proportion of macropores below the tree canopies compared with the nontimbered strata. The lack of a significant difference on the coarse‐textured soils, despite their macropore status, was attributed to differences in surface litter and plant cover, which would maintain continuous macropores at the surface and thus conduct large amounts of water. The tendency of slopes covered by cryptogamic crusts and grasses to shed run‐off and for the trees to absorb substantial quantities of water reinforced the important ecological service provided by trees, which moderates large run‐off events and captures small amounts of water leaking from the grassy patches. In the absence of these ‘ecosystem wicks’, run‐off would find its way into regional groundwater and contribute to rising salinity.     

植被发育玄武岩斜坡土体大孔隙尺寸及其主要影响因素

极端异常气候诱发植被发育斜坡发生滑坡灾害的数量逐年攀升,土体大孔隙产生的优先流对其有重要影响.本文结合水分穿透曲线和Poiseulle方程对马卡山植被发育玄武岩斜坡土体大孔隙的半径范围、数量、平均体积进行估算,分析了该区土体大孔隙分布情况及其主要影响因素.结果表明：研究区域主要植被下土体大孔隙半径在0.3~1.8 mm,主要集中在0.5~1.2 mm,1.4~1.8 mm的大半径孔隙相对较少, 而＜1.4 mm的小半径孔隙较多.随着剖面发育,大孔隙表现为上部土层多、下部土层少的特点.大孔隙平均体积决定了稳定出流速率84.7%的变异.在影响大孔隙平均体积大小的诸多因素中,植被根系质量密度与其呈线性关系,相关系数为0.70,土壤有机质含量与其呈线性关系,相关系数为0.64.     

长白山北坡两种类型森林土壤的大孔隙特征

运用亮蓝溶液染色示踪法和图像分析技术,对长白山北坡棕色针叶林土和暗棕色森林土大孔隙特征及分布进行研究,探讨影响2种类型土壤大孔隙形成的因素．结果表明：由水平剖面染色面积随土层深度的变化情况,可间接得出大孔隙在垂直土壤剖面上的变化规律;随着土层深度的增加,2种土壤的染色面积均呈减少趋势;在24h内,棕色针叶林土较暗棕色森林土大孔隙流的运移深度多10～20cm,且其大孔隙流路径多,相同面积上,前者达6条,后者只有1条;大孔隙流的存在可以使水分在土壤中的运移速度增加2～3倍;生物因素是2种土壤大孔隙形成的主要因素,由土壤动物运动形成的大孔隙数量较多,直径多为2～4mm．     

三峡库区森林土壤大孔隙特征及对饱和导水率的影响

土壤大孔隙是土体内孔径较大能优先传导水分的根孔、洞穴或裂隙,大孔隙内优先流的产生是土壤水分运动研究由均衡走向非均衡的标志。利用原状土柱的水分穿透试验,对三峡库区山地不同林型覆盖下土壤的大孔隙结构进行了研究,分析了温性阔叶林棕壤、针阔混交林黄棕壤、暖性针叶林黄壤及弃耕草地剖面内大孔隙的剖面分布特征及其对土壤饱和导水率的影响。结果表明:研究区内森林土壤的大孔隙当量孔径在0.3—3 mm之间,占土壤总体积的0.15%—4.72%。大孔隙中孔径0.3—0.6 mm的大孔隙密度最大,占大孔隙总数量的72.2%—90.4%;而孔径1 mm的孔隙仅占大孔隙总数量的1.26%—8.55%。土壤大孔隙密度和大孔隙面积比的顺序为:温性阔叶林棕壤针阔混交林黄棕壤针叶林黄壤弃耕坡地。各孔径段的大孔隙密度在不同样点均呈现A层-B层-C层逐渐减小的趋势,大孔隙密度与有机质含量呈显著正相关关系。土壤饱和导水率与不同孔径大孔隙的密度、面积比均成显著正相关关系,孔径1mm的大孔隙仅占大孔隙总数量的1.26%—8.55%,但决定了饱和导水率84.7%的变异。此外,森林土壤饱和导水率与各土壤层的有机质含量成显著正相关关系,有机质的增多有利于改善土壤的入渗性能。     

Microbiological and chemical properties of soil associated with macropores at different depths in a red-duplex soil in NSW Australia

Some agricultural soils in South Eastern Australia with duplex profiles have subsoils with high bulk density, which may limit root penetration, water uptake and crop yield. In these soils, a large proportion (up to 80%) of plant roots maybe preferentially located within the macropores or in the soil within 1–10 mm of the macropores, a zone defined as the macropore sheath (MPS). The chemical and microbiological properties of MPS soil manually dissected from a 1–3 mm wide region surrounding the macropores was compared with that of adjacent bulk soil (>10 mm from macropores) at 4 soil depths (0–20 cm, 20–40 cm, 40–60 cm and 60–80 cm). Compared to the bulk soil, the MPS soil had higher organic C, total N, bicarbonate-extractable P, Ca⁺, Cu, Fe and Mn and supported higher populations of bacteria, fungi, actinomycetes, Pseudomonas spp., Bacillus spp., cellulolytic bacteria, cellulolytic fungi, nitrifying bacteria and the root pathogen Pythium.In addition, analysis of carbon substrate utilization patterns showed the microbial community associated with the MPS soil to have higher metabolic activity and greater functional diversity than the microbial community associated with the bulk soil at all soil depths. Phospholipid fatty acids associated with bacteria and fungi were also shown to be present in higher relative amounts in the MPS soil compared to the bulk soil. Whilst populations of microbial functional groups in the MPS and the bulk soil declined with increasing soil depth, the differentiation between the two soils in microbiological properties occurred at all soil depths. Soil aggregates (< 0.5 mm diameter) associated with plant roots located within macropores were found to support a microbial community that was quantitatively and functionally different to that in the MPS soil and the bulk soil at all soil depths. The microbial community associated with these soil aggregates thus represented a third recognizable environment for plant roots and microorganisms in the subsoil.     

Influence of arbuscular mycorrhizae on heavy metal (Zn and Pb) uptake and growth of Lygeum spartum and Anthyllis cytisoides

The hypothesis tested in this paper is that, because the freshest water occurs in the largest soil pores (macropores), plants of low to moderate transpiration rate can survive in salinized soil because they preferentially extract water from macropores. The hypothesis predicts that a plant growing in a macroporous soil should have greater growth under a given salinity treatment than a similar plant growing in a soil with the same mineralogy but without macropores. This hypothesis was tested by growing bell pepper (Capsicum annuum) in the greenhouse in pots filled with either a commercial fritted clay (a highly macroporous soil) or the same clay ground to a finer texture and sieved to remove macropores and produce a microporous soil. The pots sat in pans filled with salt water. Half of the pots were irrigated once a day with fresh water and the other half received no fresh water. Plants growing in the macroporous soil had greater growth for a given salinity treatment than the plants growing in the microporous soil under both the irrigated and non-irrigated conditions. Under the irrigated condition for the highest salinity treatment, the non-reproductive fresh weight per plant, total dry weight per plant and fruit fresh weight per plant was 114 g, 12 g and 50 g, respectively, for the macroporous soil and 47 g, 4.5 g and 5 g, respectively, for the microporous soil. The results of this study provide evidence to suggest that a better understanding of what constitutes a good structure in a saline soil may aid us in our efforts to improve the management of saline soils. We suggest that it may be possible to increase the agricultural production on salinized land by no-tillage agriculture which preserves macroporosity. Possible obstacles could be the tendency of field saline-sodic soils to swell and the unavailability of relatively fresh irrigation water in areas with saline soils.     

四面山阔叶林土壤大孔隙特征与优先流的关系

为研究土壤大孔隙数量、分布特征与优先流发生之间的关系,在使用亮蓝染色法划分林地优先流发生区域基础上,利用穿透曲线理论方法,对重庆四面山典型亚热带阔叶林土壤剖面染色和未染色区域内的土壤大孔隙进行了量化分析.结果表明：研究林地土壤剖面内大孔隙半径多在0.3～3.0 mm,大孔隙率为6.3%～10.5%,随着土壤深度的增加,大孔隙呈现出聚集态的分布特征.各孔径范围内,染色区域的土壤大孔隙数量较未染色区域高出约1个数量级.半径＞0.3 mm,尤其是半径＞1.5 mm的大孔隙数量,是影响林地优先流发生的主要通道.森林土壤0.3～3.0 mm孔径范围内,大孔隙数量与其对应的土壤水分稳定出流速率呈显著的正相关关系,其中在0.7～1.5 mm和1.5～3.0 mm孔径范围内大孔隙数量与稳定出流速率相关程度最大,相关系数分别为0.842和0.879.发生优先流的染色区内大孔隙联通状况优于未染色区,两区中1.5～3.0 mm孔径范围内的联通大孔隙数量差异最大,相差78.3%.染色区内大孔隙数量随土壤深度的增加逐渐减少,“漏斗”状的孔隙分布特征可以形成有效的水压梯度,有利于水分优先运移.     

壤中流和土壤解冻深度对黑土坡面融雪侵蚀的影响

融雪侵蚀是东北黑土区土壤流失的一种重要形式,而目前有关壤中流和土壤解冻深度对融雪径流侵蚀的影响研究较少。本研究采用室内模拟试验,设计两个融雪径流量(1和4 L·min^-1)和两个土壤解冻深度(5和10 cm),以及有、无壤中流处理,分析壤中流和土壤解冻深度对黑土区坡面融雪侵蚀的影响。结果表明: 1)壤中流处理下坡面融雪径流深度和侵蚀量分别是无壤中流处理的1.1～1.2倍和1.3～1.9倍。两个融雪径流量下,当土壤解冻深度由5 cm增加到10 cm时,无壤中流处理下坡面融雪径流深度和侵蚀量分别增加10.0%～13.5%和15.4%～37.1%;而有壤中流处理下坡面融雪径流深度增加6.5%～8.5%,融雪侵蚀量则无显著变化。2)坡面细沟发育受壤中流、土壤解冻深度和融雪径流量的综合影响,各处理下细沟侵蚀量占坡面融雪侵蚀量的72%以上。3)壤中流发生使坡面径流流速和径流剪切力分别增加20.3%～23.2%和37.0%～51.3%,Darcy-Weisbach阻力系数减少9.0%～21.4%,从而增加了坡面融雪侵蚀量;且壤中流发生促进了坡面细沟发育,其细沟侵蚀量较无壤中流处理增加43.6%～69.9%,也导致坡面融雪侵蚀量增加。无壤中流条件下,土壤解冻深度加剧坡面融雪侵蚀的主要原因是随着土壤解冻深度的增加,坡面径流侵蚀能力和可蚀性物质来源增加,导致融雪径流侵蚀量增加。此外,土壤解冻深度对壤中流条件下细沟形态发育也有明显的影响,土壤解冻深度为5 cm时,细沟横向加宽作用显著;而土壤解冻深度为10 cm时,细沟下切侵蚀作用更显著。本研究加深了对黑土区融雪侵蚀机理的认识,可为水蚀模型的研发提供理论指导。     

Effect of soil acidity, soil strength and macropores on root growth and morphology of perennial grass species differing in acid-soil resistance

It is unclear whether roots of acid-soil resistant plants have significant advantages, compared with acid-soil sensitive genotypes, when growing in high-strength, acid soils or in acid soils where macropores may allow the effects of soil acidity and strength to be avoided. The responses of root growth and morphology to soil acidity, soil strength and macropores by seedlings of five perennial grass genotypes differing in acid-soil resistance were determined, and the interaction of soil acidity and strength for growth and morphology of roots was investigated. Soil acidity and strength altered root length and architecture, root hair development, and deformed the root tip, especially in acid-soil sensitive genotypes. Root length was restricted to some extent by soil acidity in all genotypes, but the adverse impact of soil acidity on root growth by acid-soil resistant genotypes was greater at high levels of soil strength. Roots reacted to soil acidity when growing in macropores, but elongation through high-strength soil was improved. Soil strength can confound the effect of acidity on root growth, with the sensitivity of acid-resistant genotypes being greater in high-strength soils. This highlights the need to select for genotypes that resist both acidity and high soil strength.     

Effect of Watering and Soil Moisture on Mercury Emissions from Soils

This paper presents data from experiments that measured Mercury (Hg) flux as a function of water addition and subsequent soil drying, and maintenance of soil water content over time utilizing small dynamic gas exchange chambers and large mesocosms. When soil surfaces were dry and water was added at an amount less than that necessary to saturate the soil an immediate large (relative to dry soil flux) release of Hg occurred. Diel Hg emissions from soils, unenriched (0.02 μg g⁻¹) and enriched (3 μg g⁻¹) in Hg and wet below saturation, were significantly elevated above that occurring from dry soils (2–5 times depending on soil water content) for weeks to months. Enhancement of emissions from wet soils in direct sunlight were greater than that from soils shaded or in the dark suggesting that a synergism exists between soil moisture and light. When soils were watered to saturation Hg emissions were suppressed or remained the same depending on the degree of saturation. It is hypothesized that the addition of soil water in amounts less than that necessary to saturate the soil surface results in an immediate release of elemental Hg from soil surface as the more polar water molecule out competes Hg for binding sites. As the water moves into the soil, Hg adsorbed to soil particles is desorbed into soil gas and dissolved in the soil water. The process of evaporation facilitates movement of Hg as mass flow to the soil surface where it is made available for subsequent release. The latter is hypothesized to be an important process by which Hg is recharged at the soil–air interface.     

Vegetation patterns in relation to micro-scale landforms in hilly land regions

Spatial structures of landforms as constants affecting vegetation patterns are discussed based on analyses of hilly land regions, mostly in the vicinity of Sendai, northeast Japan. The lower part of a hillslope is characterized by relatively active processes of soil erosion, landslides and slope failure. It supports a plant community different from that on the upper part of the hillslope. These two parts are termed the lower hillslope and the upper hillslope, respectively. The upper hillslope consists of valley heads with no stream water nor stream channels. Since a valley head is comprised of several micro-scale landform units, an upper hillslope can be subdivided into these landform units. Plant communities vary in their species compositions and structures as well as in some other ecological characteristics paralleling changes in their respective micro-scale landform units. However, the variations in species composition within upper hillslopes are not as extreme as those between the upper and lower hillslopes. xx]Papers presented at the Vth INTECOL Congress at YOKO-hama 1990.     

黄土丘陵沟壑区植被对不同空间尺度水沙关系的影响

根据晋西离石试验站的观测结果和相关文献的数据,研究了黄土丘陵沟壑区植被对坡面小区、全坡面、小流域及中大流域4个空间尺度水沙关系的影响。对梁峁坡坡面小区言,由于植被提高了土壤抗蚀性,因此植被不仅通过减水来减沙,也通过改变水沙关系来减沙。但在全坡面尺度,土壤侵蚀以沟蚀为主,由于植被措施难以改变沟道的各种水利参数,也难以有效控制切沟沟壁的重力侵蚀,导致水流进入沟道后仍然可以获取充足的泥沙,因此认为植被不会改变全坡面尺度的水沙关系。同样对于各级流域,由于植被措施难以改变沟道的输沙能力和黄土丘陵沟壑区流域泥沙来源充沛的特点,因此植被措施也不会改变其水沙关系,植被的减沙效应仅通过减水来实现。对离石试验站的一对水土保持对比沟的研究表明,即使在沟道已有茂密植被生长的情况下,高含沙水流的输沙能力也没有改变,这使得两者的水沙关系统计上可以认为完全一致。由于大流域水沙关系主要取决于沟道或河道的特性,而植被等坡面措施很难改变沟道或河道特性,因此认为流域尺度越大,植被越难以改变其水沙关系。     

黄土塬区土地利用方式对土壤大孔隙特征的影响

土壤导水率及大孔隙数量是决定降雨-入渗的重要参数,对模拟土壤水分及溶质运移、建立流域水文模型具有重要意义.为确定黄土区土地利用方式对土壤大孔隙特征的影响,本文通过Hood入渗仪及土壤水分特征曲线,比较了该区刺槐林地、草地、小麦地、苹果林地土壤导水率、大孔隙度和大孔隙连通性的差异.结果表明: 研究区刺槐林地、草地、小麦地、苹果林地的平均饱和导水率分别为58.60×10^-6、54.90×10^-6、35.30×10^-6、23.40×10^-6 m·s^-1,存在显著性差异.不同土地利用方式下的单位面积有效大孔隙数目、大孔隙度及大孔隙连通性均依次为:刺槐林地≈草地>小麦地>苹果林地.植被恢复通过植物根系穿插、土壤动物活动等形成大孔隙,可显著提高土壤入渗性能.黄土区应坚持林草植被恢复措施.     

The influence of ants on soil and water losses from an orange orchard in eastern Spain

Herbicide applications have greatly reduced plant cover, and increased soil erosion on a new orange orchard planted on valley slopes in eastern Spain. This has increased the importance of soil fauna, such as ants, in regulating soil erosion processes. Ants increase water infiltration rates by forming soil macropores during nest construction, but new soil brought to the surface by ant activity could increase the sediments available for erosion. Simulated rainfall experiments were conducted on 20 paired plots (20 with ant activity and 20 controls) to study the impact of ants on surface water flow and sediment movement in an intensively managed orange orchard near Valencia, Spain. Simulated rainfall was applied to each plot at a rate of 55 mm/h on a 0.25 m² area for 1 h. We found a reduction of soil bulk density, an increase in soil organic matter, and an increase in macropore flow in ant‐affected soils, as compared to soil without ant activity. These ant‐induced soil changes increased water infiltration rates and runoff discharge. However, the fresh, unconsolidated soil brought to the surface during nest construction resulted in greater soil loss on two plots than their ant‐free controls. Ants can be an important factor in soil erosion processes when surface vegetation is removed by intensive herbicide use.     

连栽桉树人工林土壤大孔隙特征及其对饱和导水率的影响

速生人工林多代连栽容易导致土地水源涵养能力下降。土壤大孔隙以优先流的形式补充地下水,是定量研究土壤水分运动的重要指标。以连栽1-4代桉树人工纯林为研究对象（记录为Ⅰ、Ⅱ、Ⅲ、Ⅳ）,采用水分穿透曲线法,绘制水分穿透曲线,结合Poiseulle方程计算出大孔隙数量、半径及饱和导水率等指标,对土壤大孔隙特征及其对饱和导水率的影响进行研究。结果表明：（1）桉树人工林土壤的出流速率总体表现先匀速增加后趋于稳定,稳定出流速率总体表现为I > II > III > IV。（2）大孔隙半径范围在0.3-1.5 mm,主要集中于0.4-0.6 mm,随土层深度增加显著减小（P<0.05）。大孔隙数量范围在3.56×10⁴-4.81×10⁵个/m²。随着连栽代次的增加,大孔隙孔径范围变小,同一孔径范围的大孔隙数量减少。土壤容重与大孔隙特征呈极显著负相关关系;有机质含量与大孔隙特征呈极显著正相关关系。（3）各样地土壤饱和导水率范围在0.41-4.50 mm/min,并随着连栽代次增加而降低。将大孔隙的总数量、平均体积与土壤饱和导水率进行线性拟合,拟合方程为：y=ax+b=,（R²>0.66）。综上,随着桉树人工林连栽代次的增加,土壤大孔隙孔径范围缩小、同等半径的大孔隙数量减少,饱和导水率降低,土壤入渗及导水性能减弱,容易造成水土流失。     

Distribution of cutin and suberin biomarkers under forest trees with different root systems

Background and aims

The rhizosphere, the soil immediately surrounding roots, provides a critical bridge for water and nutrient uptake. The rhizosphere is influenced by various forms of root–soil interactions of which mechanical deformation due to root growth and its effects on the hydraulics of the rhizosphere are the least studied. In this work, we focus on developing new experimental and numerical tools to assess these changes.

Methods

This study combines X-ray micro-tomography (XMT) with coupled numerical simulation of fluid and soil deformation in the rhizosphere. The study provides a new set of tools to mechanistically investigate root-induced rhizosphere compaction and its effect on root water uptake. The numerical simulator was tested on highly deformable soil to document its ability to handle a large degree of strain.

Results

Our experimental results indicate that measured rhizosphere compaction by roots via localized soil compaction increased the simulated water flow to the roots by 27 % as compared to an uncompacted fine-textured soil of low bulk density characteristic of seed beds or forest topsoils. This increased water flow primarily occurred due to local deformation of the soil aggregates as seen in the XMT images, which increased hydraulic conductivity of the soil. Further simulated root growth and deformation beyond that observed in the XMT images led to water uptake enhancement of ~50 % beyond that due to root diameter increase alone and demonstrated the positive benefits of root compaction in low density soils.

Conclusions

The development of numerical models to quantify the coupling of root driven compaction and fluid flow provides new tools to improve the understanding of plant water uptake, nutrient availability and agricultural efficiency. This study demonstrated that plants, particularly during early growth in highly deformable low density soils, are involved in active mechanical management of their surroundings. These modeling approaches may now be used to quantify compaction and root growth impacts in a wide range of soils.     

Ponded infiltration into soil with biopores — field experiment and modeling

Preferential movement of water in macropores plays an important role when the process of ponded infiltration in natural porous systems is studied. For example, the detailed knowledge of water flow through macropores is of a major importance when predicting runoff responses to rainfall events. The main objectives of this study are to detect preferential movement of water in Chernozem soil and to employ numerical modeling to describe the variably saturated flow during a field ponded infiltration experiment. The infiltration experiment was performed at the Macov experimental station (Calcari-Haplic Chernozem in Danubian Lowland, Slovakia). The experiment involved single ring ponded infiltration. At the quasi steady state phase of the experiment dye tracer was added to the infiltrating water. Then the soil profile was excavated and the penetration pattern of the applied tracer was recorded. The abundance of biopores as a product of fauna and flora was found. To quantify the preferential flow effects during the infiltration experiment, three-dimensional axisymmetric simulations were carried out by a two-dimensional dual-continuum numerical model. The water flow simulations based on measured hydraulic characteristics without consideration of preferential flow effects failed to describe the infiltration experiment adequately. The 3D axisymmetric simulation based on dual-permeability approach provided relatively realistic space-time distribution of soil water pressure below the infiltration ring.