ASSESSMENT OF THE SIMPLIFIED FALLING HEAD TECHNIQUE TO MEASURE THE FIELD SATURATED SOIL HYDRAULIC CONDUCTIVITY

The Simplified Falling Head (SFH) technique to measure field saturated soil hydraulic conductivity, Kfs, has received little testing or comparison with other techniques. Different experiments were carried out to i) determine the effect of ring size on the measured conductivity; ii) compare the SFH and Pressure Infiltrometer (PI) techniques in a clay loam soil; and iii) assess the indirect approach to estimate the * parameter used in the SFH methodology. Sampling a relatively large number of sites allowed to detect a statistically significant relationship between the Kfs values obtained with rings differing in diameter (0.15 and 0.30 m, respectively). This relationship suggested that a measurement carried out with a small ring contains enough information to make an approximate prediction of the Kfs value that would be obtained at the same site with a larger ring. The SFH and PI techniques yielded similar means but substantially different coefficients of variation (much higher for the SFH technique). The two methods should be considered complementary, being usable to determine Kfs at the beginning (SFH) and at a later stage (PI) of a ponding infiltration process. Using * values directly measured by the tension infiltrometer or indirectly estimated on the basis of a general description of soil characteristics did not modify significantly the Kfs predictions obtained with the SFH technique. In conclusion, this investigation gave support to the use of the SFH technique for a rapid and reasonably simple determination of, at least, the order of magnitude of Kfs

Evaluation of soil physical quality under different soil land uses in a small Sicilian watershed

Sustainability of extensive rain fed agriculture needs assessment of land use effects on soil physical and hydraulic properties. Several soil physical quality indices were determined for four adjacent areas in a small Sicilian watershed, that were characterized by a different land use, namely cropland (C), olive grove (O), grassland (G) and eucalyptus plantation (E). Soil texture was similar for the considered areas, even if the no-tilled soils (G and E) showed a higher clay content in the top layer (0-20 cm) than in the lower layer (20-40 cm). The bulk density of the top layer ranged between 1.20-1.43 g cm-3 (C < G < O < E), with significant differences between C and E. In the lower layer, it ranged between 1.16-1.43 g cm-3 (C < O < E < G), with bulk density of C that was significantly smaller than that of the other land uses. The organic matter content was generally low and comparable for the different areas (in average 1.6%). The near-saturated soil hydraulic conductivity values were significantly higher for no-tilled (G, E) than tilled soils (C, O), whereas the opposite result was found for smaller degrees of saturation. The Dexter’s soil quality index assumed similar values in both the top (0.024-0.047) and the lower layer (0.024-0.040), with the higher values associated to tilled soils. According to existing guidelines, the soil physical quality of the selected areas was generally poor independently of the land use. However, the cropland showed a better quality than the other land uses

Water transmission properties of a sandy-loam soil estimated with Beerkan runs differing by the infiltration time criterion

The Beerkan method consists of a ponded infiltration experiment from a single ring inserted a small depth into the soil. Fixed, small volumes of water are repeatedly poured into the ring to maintain a quasi-zero head on the soil surface. According to the standard Beerkan infiltration run, a new water volume is poured on the infiltration surface when the previously applied volume has completely infiltrated and the soil surface is entirely exposed to air (ta criterion). However, water could also be applied when the soil exposition to air begins (to criterion) or half the soil surface is exposed to air (tm criterion). The effect of the infiltration time criterion on determination of the water transmission properties of a sandy-loam soil was tested. As compared with the standard ta criterion, the two alternative criteria (to, tm) yielded higher and/or more variable estimates of soil water transmission properties. The saturated soil hydraulic conductivity, Ks, was the most sensitive property to the infiltration time criterion. However, statistically significant differences for Ks were not practically substantial since they did not exceed a factor of 1.7. Infiltration time effects likely occurred due to differences between ponding depth of water, soil water pressure head gradient, air entrapment and soil mechanical disturbance. The standard ta criterion was suggested for performing a Beerkan experiment in the field since it appears to yield the most reliable estimates of a mean value. However, the to criterion could be considered in dual permeability soils to maintain macropores active. Factors that could appear minor in the context of an experiment can have statistically relevant effects on water transmission properties

Influence of the pressure head sequence on the soil hydraulic conductivity determined with tension infiltrometer

An increasing and a decreasing sequence of pressure head, h0, values were applied with the tension infiltrometer (TI) to determine the corresponding hydraulic conductivity, K0. The pressure head sequence is expected to influence the K0 results given the hysteretic nature of the hydraulic conductivity relationship. The objective of this study was to evaluate the influence of the selected pressure head sequence on the hydraulic conductivity of a sandy loam soil measured by a multipotential TI experiment. Twenty experiments were carried out by applying h0 values varying between -150 and +5 mm (site A). The h0 values ranged from -150 to -10 mm in another 20 spots (site B). Both wetting and drying values of K0 corresponding to h0 = -150, -75, and -30 mm were calculated for each experiment using the measured steady-state flow rates. At both sites, higher K0 results were obtained with the descending h0 sequence than with the ascending one. The deviations between the two sequences were more noticeable in site A (deviations by a factor ranging from 2.1 to 3.3, depending on h0) than in site B (deviations by a factor ranging from 1.0 to 2.2), and the values decreased as h0 increased. For most of the considered type of site/pressure head combinations, the differences between the K0 results were statistically significant (P = 0.05). In all cases, the coefficients of variation of the K0 data obtained with the two sequences differed at most by a factor of 1.2, suggesting that the applied h0 sequence did not affect appreciably the relative variability of the K0 results. It was concluded that the dependence of the K0 estimates on both the pressure head sequence (ascending or descending) and the highest value of h0 used within a descending sequence experiment may be neglected for a rough hydraulic characterization of the selected area. However, both factors should be maintained constant in order to obtain truly comparable K0 data from different experiments

Infiltration Measurements for Soil Hydraulic Characterization

This book summarises the main results of many contributions from researchers worldwide who have used the water infiltration process to characterize soil in the field. Determining soil hydrodynamic properties is essential to interpret and simulate the hydrological processes of economic and environmental interest. This book can be used as a guide to soil hydraulic characterization and in addition it gives a complete description of the treated techniques, including an outline of the most significant research results, with the main points that still needing development and improvement

Artificial Neural Networks for Predicting the Water Retention Curve of Sicilian Agricultural Soils

Modeling soil-water regime and solute transport in the vadose zone is strategic for estimating agricultural productivity and optimizing irrigation water management. Direct measurements of soil hydraulic properties, i.e., the water retention curve and the hydraulic conductivity function, are often expensive and time-consuming, and represent a major obstacle to the application of simulation models. As a result, there is a great interest in developing pedotransfer functions (PTFs) that predict the soil hydraulic properties from more easily measured and/or routinely surveyed soil data, such as particle size distribution, bulk density (ρb), and soil organic carbon content (OC). In this study, application of PTFs was carried out for 359 Sicilian soils by implementing five different artificial neural networks (ANNs) to estimate the parameter of the van Genuchten (vG) model for water retention curves. The raw data used to train the ANNs were soil texture, ρb, OC, and porosity. The ANNs were evaluated in their ability to predict both the vG parameters, on the basis of the normalized root-mean-square errors (NRMSE) and normalized mean absolute errors (NMAE), and the water retention data. The Akaike's information criterion (AIC) test was also used to assess the most efficient network. Results confirmed the high predictive performance of ANNs with four input parameters (clay, sand, and silt fractions, and OC) in simulating soil water retention data, with a prediction accuracy characterized by MAE = 0.026 and RMSE = 0.069. The AIC efficiency criterion indicated that the most efficient ANN model was trained with a relatively low number of input nodes

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

The lateral saturated hydraulic conductivity, Ks,l, is the soil property that mostly governs subsurface flow in hillslopes. Determinations of Ks,lat the hillslope scale are expected to yield valuable information for interpreting and modeling hydrological processes since soil heterogeneities are functionally averaged in this case. However, these data are rare since the experiments are quite difficult and costly. In this investigation, that was carried out in Sardinia (Italy), large-scale determinations of Ks,lwere done in two adjacent hillslopes covered by a Mediterranean maquis and grass, respectively, with the following objectives: i) to evaluate the effect of land use change on Ks,l, and ii) to compare estimates of Ks,lobtained under natural and artificial rainfall conditions. Higher Ks,lvalues were obtained under the maquis than in the grassed soil since the soil macropore network was better connected in the maquis soil. The lateral conductivity increased sharply close to the soil surface. The sharp increase of Ks,lstarted at a larger depth for the maquis soil than the grassed one. The Ks,lvalues estimated during artificial rainfall experiments agreed with those obtained during the natural rainfall periods. For the grassed site, it was possible to detect a stabilization of Ks,lin the upper soil layer, suggesting that flow transport capacity of the soil pore system did not increase indefinitely. This study highlighted the importance of the experimental determination of Ks,lat the hillslope scale for subsurface modeling, and also as a benchmark for developing appropriate sampling methodologies based on near-point estimation of Ks,l

Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil

[EN] Saturated soil hydraulic conductivity, K-s, data collected by ponding infiltrometer methods and usual experimental procedures could be unusable for interpreting field hydrological processes and particularly rainfall infiltration. The K-s values determined by an infiltrometer experiment carried out by applying water at a relatively large distance from the soil surface could however be more appropriate to explain surface runoff generation phenomena during intense rainfall events. In this study, a link between rainfall simulation and ponding infiltrometer experiments was established for a sandy-loam soil. The height of water pouring for the infiltrometer run was chosen, establishing a similarity between the gravitational potential energy of the applied water, E-p, and the rainfall kinetic energy, E-k. To test the soundness of this procedure, the soil was sampled with the Beerkan estimation of soil transfer parameters procedure of soil hydraulic characterization and two heights of water pouring (0.03m, i.e., usual procedure, and 0.34m, yielding E-p=E-k). Then, a comparison between experimental steady-state infiltration rates, i(sR), measured with rainfall simulation experiments determining runoff production and K-s values for the two water pouring heights was carried out in order to discriminate between theoretically possible (i(sR)K(s)) and impossible (i(sR)3.0.co;2-vCerdà, A. (1999). Seasonal and spatial variations in infiltration rates in badland surfaces under Mediterranean climatic conditions. Water Resources Research, 35(1), 319-328. doi:10.1029/98wr01659Cerdà, A. (2000). Aggregate stability against water forces under different climates on agriculture land and scrubland in southern Bolivia. Soil and Tillage Research, 57(3), 159-166. doi:10.1016/s0167-1987(00)00155-0Cerdà, A. (2001). Effects of rock fragment cover on soil infiltration, interrill runoff and erosion. European Journal of Soil Science, 52(1), 59-68. doi:10.1046/j.1365-2389.2001.00354.xCerdà, A., & Doerr, S. H. (2007). Soil wettability, runoff and erodibility of major dry-Mediterranean land use types on calcareous soils. Hydrological Processes, 21(17), 2325-2336. doi:10.1002/hyp.6755Cerdà, A., Ibáñez, S., & Calvo, A. (1997). Design and operation of a small and portable rainfall simulator for rugged terrain. Soil Technology, 11(2), 163-170. doi:10.1016/s0933-3630(96)00135-3Di Prima, S. (2015). Automated single ring infiltrometer with a low-cost microcontroller circuit. Computers and Electronics in Agriculture, 118, 390-395. doi:10.1016/j.compag.2015.09.022Di Prima, S., Lassabatere, L., Bagarello, V., Iovino, M., & Angulo-Jaramillo, R. (2016). Testing a new automated single ring infiltrometer for Beerkan infiltration experiments. Geoderma, 262, 20-34. doi:10.1016/j.geoderma.2015.08.006Diodato, N., Verstraeten, G., & Bellocchi, G. (2012). DECADAL MODELLING OF RAINFALL EROSIVITY IN BELGIUM. Land Degradation & Development, 25(6), 511-519. doi:10.1002/ldr.2168Gee GW Bauder JW 1986 Particle-size analysis SSSA Book Series 383 411Haverkamp, R., Ross, P. J., Smettem, K. R. J., & Parlange, J. Y. (1994). Three-dimensional analysis of infiltration from the disc infiltrometer: 2. Physically based infiltration equation. Water Resources Research, 30(11), 2931-2935. doi:10.1029/94wr01788Iovino, M., Castellini, M., Bagarello, V., & Giordano, G. (2013). Using Static and Dynamic Indicators to Evaluate Soil Physical Quality in a Sicilian Area. Land Degradation & Development, 27(2), 200-210. doi:10.1002/ldr.2263Iserloh, T., Ries, J. B., Arnáez, J., Boix-Fayos, C., Butzen, V., Cerdà, A., … Wirtz, S. (2013). European small portable rainfall simulators: A comparison of rainfall characteristics. CATENA, 110, 100-112. doi:10.1016/j.catena.2013.05.013Iserloh, T., Ries, J. B., Cerdà, A., Echeverría, M. T., Fister, W., Geißler, C., … Seeger, M. (2013). Comparative measurements with seven rainfall simulators on uniform bare fallow land. Zeitschrift für Geomorphologie, Supplementary Issues, 57(1), 11-26. doi:10.1127/0372-8854/2012/s-00085Keesstra, S., Pereira, P., Novara, A., Brevik, E. C., Azorin-Molina, C., Parras-Alcántara, L., … Cerdà, A. (2016). Effects of soil management techniques on soil water erosion in apricot orchards. Science of The Total Environment, 551-552, 357-366. doi:10.1016/j.scitotenv.2016.01.182B. A. King, & D. L. Bjorneberg. (2012). Transient Soil Surface Sealing and Infiltration Model for Bare Soil under Droplet Impact. Transactions of the ASABE, 55(3), 937-945. doi:10.13031/2013.41525Lado, M., Paz, A., & Ben-Hur, M. (2004). Organic Matter and Aggregate-Size Interactions in Saturated Hydraulic Conductivity. Soil Science Society of America Journal, 68(1), 234-242. doi:10.2136/sssaj2004.2340Lassabatere, L., Angulo-Jaramillo, R., Goutaland, D., Letellier, L., Gaudet, J. P., Winiarski, T., & Delolme, C. (2010). Effect of the settlement of sediments on water infiltration in two urban infiltration basins. Geoderma, 156(3-4), 316-325. doi:10.1016/j.geoderma.2010.02.031Lassabatère, L., Angulo-Jaramillo, R., Soria Ugalde, J. M., Cuenca, R., Braud, I., & Haverkamp, R. (2006). Beerkan Estimation of Soil Transfer Parameters through Infiltration Experiments-BEST. Soil Science Society of America Journal, 70(2), 521-532. doi:10.2136/sssaj2005.0026Lassabatere, L., Angulo-Jaramillo, R., Soria-Ugalde, J. M., Šimůnek, J., & Haverkamp, R. (2009). Numerical evaluation of a set of analytical infiltration equations. Water Resources Research, 45(12). doi:10.1029/2009wr007941Lassabatere, L., Yilmaz, D., Peyrard, X., Peyneau, P. E., Lenoir, T., Šimůnek, J., & Angulo-Jaramillo, R. (2014). New Analytical Model for Cumulative Infiltration into Dual-Permeability Soils. Vadose Zone Journal, 13(12), vzj2013.10.0181. doi:10.2136/vzj2013.10.0181Lassu, T., Seeger, M., Peters, P., & Keesstra, S. D. (2015). The Wageningen Rainfall Simulator: Set-up and Calibration of an Indoor Nozzle-Type Rainfall Simulator for Soil Erosion Studies. Land Degradation & Development, 26(6), 604-612. doi:10.1002/ldr.2360BISSONNAIS, Y. (1996). Aggregate stability and assessment of soil crustability and erodibility: I. Theory and methodology. European Journal of Soil Science, 47(4), 425-437. doi:10.1111/j.1365-2389.1996.tb01843.xLi, X.-Y., González, A., & Solé-Benet, A. (2005). Laboratory methods for the estimation of infiltration rate of soil crusts in the Tabernas Desert badlands. CATENA, 60(3), 255-266. doi:10.1016/j.catena.2004.12.004Lilliefors, H. W. (1967). On the Kolmogorov-Smirnov Test for Normality with Mean and Variance Unknown. Journal of the American Statistical Association, 62(318), 399-402. doi:10.1080/01621459.1967.10482916Liu, H., Lei, T. W., Zhao, J., Yuan, C. P., Fan, Y. T., & Qu, L. Q. (2011). Effects of rainfall intensity and antecedent soil water content on soil infiltrability under rainfall conditions using the run off-on-out method. Journal of Hydrology, 396(1-2), 24-32. doi:10.1016/j.jhydrol.2010.10.028Mualem, Y., Assouline, S., & Rohdenburg, H. (1990). Rainfall induced soil seal (A) A critical review of observations and models. CATENA, 17(2), 185-203. doi:10.1016/0341-8162(90)90008-2Mubarak, I., Angulo-Jaramillo, R., Mailhol, J. C., Ruelle, P., Khaledian, M., & Vauclin, M. (2010). Spatial analysis of soil surface hydraulic properties: Is infiltration method dependent? Agricultural Water Management, 97(10), 1517-1526. doi:10.1016/j.agwat.2010.05.005Nunes, A. N., Lourenço, L., Vieira, A., & Bento-Gonçalves, A. (2014). Precipitation and Erosivity in Southern Portugal: Seasonal Variability and Trends (1950-2008). Land Degradation & Development, 27(2), 211-222. doi:10.1002/ldr.2265Prosdocimi, M., Jordán, A., Tarolli, P., Keesstra, S., Novara, A., & Cerdà, A. (2016). The immediate effectiveness of barley straw mulch in reducing soil erodibility and surface runoff generation in Mediterranean vineyards. Science of The Total Environment, 547, 323-330. doi:10.1016/j.scitotenv.2015.12.076Reynolds, W. D., Bowman, B. T., Brunke, R. R., Drury, C. F., & Tan, C. S. (2000). Comparison of Tension Infiltrometer, Pressure Infiltrometer, and Soil Core Estimates of Saturated Hydraulic Conductivity. Soil Science Society of America Journal, 64(2), 478-484. doi:10.2136/sssaj2000.642478xRockström, J., Jansson, P.-E., & Barron, J. (1998). Seasonal rainfall partitioning under runon and runoff conditions on sandy soil in Niger. On-farm measurements and water balance modelling. Journal of Hydrology, 210(1-4), 68-92. doi:10.1016/s0022-1694(98)00176-0Shainberg, I., & Singer, M. J. (1988). Drop Impact Energy-Soil Exchangeable Sodium Percentage Interactions in Seal Formation. Soil Science Society of America Journal, 52(5), 1449-1452. doi:10.2136/sssaj1988.03615995005200050046xShaver, T. M., Peterson, G. A., Ahuja, L. R., & Westfall, D. G. (2013). Soil sorptivity enhancement with crop residue accumulation in semiarid dryland no-till agroecosystems. Geoderma, 192, 254-258. doi:10.1016/j.geoderma.2012.08.014Somaratne, N. M., & Smettem, K. R. J. (1993). Effect of cultivation and raindrop impact on the surface hydraulic properties of an Alfisol under wheat. Soil and Tillage Research, 26(2), 115-125. doi:10.1016/0167-1987(93)90038-qSouza, E. S., Antonino, A. C. D., Heck, R. J., Montenegro, S. M. G. L., Lima, J. R. S., Sampaio, E. V. S. B., … Vauclin, M. (2014). Effect of crusting on the physical and hydraulic properties of a soil cropped with Castor beans (Ricinus communis L.) in the northeastern region of Brazil. Soil and Tillage Research, 141, 55-61. doi:10.1016/j.still.2014.04.004Tricker, A. S. (1979). The design of a portable rainfall simulator infiltrometer. Journal of Hydrology, 41(1-2), 143-147. doi:10.1016/0022-1694(79)90111-2Turner, R. K., van den Bergh, J. C. J. M., Söderqvist, T., Barendregt, A., van der Straaten, J., Maltby, E., & van Ierland, E. C. (2000). Ecological-economic analysis of wetlands: scientific integration for management and policy. Ecological Economics, 35(1), 7-23. doi:10.1016/s0921-8009(00)00164-6Van De Giesen, N. C., Stomph, T. J., & de Ridder, N. (2000). Scale effects of Hortonian overland flow and rainfall-runoff dynamics in a West African catena landscape. Hydrological Processes, 14(1), 165-175. doi:10.1002/(sici)1099-1085(200001)14:13.0.co;2-1Vandervaere, J.-P., Vauclin, M., Haverkamp, R., Peugeot, C., Thony, J.-L., & Gilfedder, M. (1998). PREDICTION OF CRUST-INDUCED SURFACE RUNOFF WITH DISC INFILTROMETER DATA. Soil Science, 163(1), 9-21. doi:10.1097/00010694-199801000-00003White, I., Sully, M. J., & Melville, M. D. (1989). Use and Hydrological Robustness of Time-to-Incipient-Ponding. Soil Science Society of America Journal, 53(5), 1343-1346. doi:10.2136/sssaj1989.03615995005300050007xXu, X., Kiely, G., & Lewis, C. (2009). Estimation and analysis of soil hydraulic properties through infiltration experiments: comparison of BEST and DL fitting methods. Soil Use and Management, 25(4), 354-361. doi:10.1111/j.1475-2743.2009.00218.xYilmaz, D., Lassabatere, L., Angulo-Jaramillo, R., Deneele, D., & Legret, M. (2010). Hydrodynamic Characterization of Basic Oxygen Furnace Slag through an Adapted BEST Method. Vadose Zone Journal, 9(1), 107. doi:10.2136/vzj2009.0039YOUNGS, E. G. (1987). Estimating hydraulic conductivity values from ring infiltrometer measurements. Journal of Soil Science, 38(4), 623-632. doi:10.1111/j.1365-2389.1987.tb02159.xZimmermann, A., Schinn, D. S., Francke, T., Elsenbeer, H., & Zimmermann, B. (2013). Uncovering patterns of near-surface saturated hydraulic conductivity in an overland flow-controlled landscape. Geoderma, 195-196, 1-11. doi:10.1016/j.geoderma.2012.11.00

BEST-2K Method for Characterizing Dual-Permeability Unsaturated Soils with Ponded and Tension Infiltrometers

This study presents a new method (BEST-2K) that extends the existing BEST methods for use in characterizing the water retention and hydraulic conductivity functions of matrix and fast-flow regions in dual-permeability soils. BEST-2K requires input information from two water infiltration experiments that are performed under ponded (Beerkan) and unsaturated (tension infiltrometer) conditions at the surface. Other required inputs include water content measurements and the traditional BEST inputs (particle size distribution and bulk density). In this study, first, a flowchart of the BEST-2K method was developed and illustrated with analytically generated data for a synthetic dual-permeability soil. Next, a sensitivity analysis was performed to assess the accuracy of BEST-2K and its sensitivity to the quality of the inputs (water contents and cumulative infiltrations, and the prior estimation of the volume ratio occupied by the fast-flow region). Lastly, BEST-2K was applied to real experimental data to characterize three soils that are prone to preferential flow. BEST-2K was found to be a particularly useful tool that combines experimental and modeling approaches for characterizing dual-permeability soils and, more generally, soils prone to preferential flows