Assessing the effect of soil crack dynamics on hydraulic properties of agricultural soil from reduced tillage and conventional tillage fields, Wallonia-Belgium

2020 ◽  
Author(s):  
Njaka Andriamanantena Ralaizafisoloarivony
Keyword(s):  
Agricultural Soil ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Crack Formation ◽  
Cultural Practices ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Soil Hydraulic Properties ◽  
Disturbed Soil ◽  
Micro Cracks

<p>Crack formation and development have been a general concern in agricultural science. Cracks contribute to soil aeration, aggregate formation, and easy root penetration. However, cracks facilitated water evaporation, accelerated soil desiccation, allowed deep infiltration of pesticides/pollutants through preferential flow, and polluted the shallow water-table in Belgium.  From many years, farmers reported the presence of cracks in their field; however, few studies investigated cracks formation from agricultural soil under different cultural practices. This research investigated the effect of cultural practices (conventional and reduced tillage) on crack formation and on soil hydraulic properties.</p><p> </p><p>Soils were collected right from the agricultural field and processed (in laboratory) under evaporation experiment on a small drying chamber. Ceramic-IR-emitter heated the chamber while sensors (PT1000, DHT22) measured the temperature and relative humidity. Digital camera took photos of the soil surface at 30min interval. Balance and tensiometer commanded by a datalogger (CR800), recorded the soil hydraulic properties (water suction, water retention, evaporation rate etc.). Cracks were monitored and extracted using image analysis performed by ImageJ and PCAS software. The soil water retention curve (SWRC) was fitted with the bimodal models of Durner (1994) and Seki (2007). The output data were analysed statistically using appropriate software. Three treatments were considered including: disturbed soil, conventional tillage and reduced tillage.  </p><p> </p><p>The results showed higher cracks formation on disturbed soil > reduced-tillage > conventional-tillage due to loose of soil cohesion, soil organic content, soil aggregation, biological activities, and soil porosity. Crack formed at low matrix suction for reduce tillage, but higher tension for conventional tillage and disturbed soil. The soil evaporation rate was also greater in reduced-tillage > conventional tillage > disturbed soil. The effect of cracks affected the SWRC for reduced tillage and disturbed soil. The result suspected the presence of pre-installing (or micro)cracks in the reduced-tillage samples. Future study is needed to assess the presence of pre-(micro)-cracks in soil using X-ray microtomography. </p>

scholarly journals Assessing Soil Crack Dynamics and Water Evaporation during Dryings of Agricultural Soil from Reduced Tillage and Conventional Tillage Fields

Proceedings ◽  
2020 ◽  
Vol 30 (1) ◽  
pp. 59
Author(s):  
Njaka Ralaizafisoloarivony ◽  
Aurore Degré ◽  
Benoit Mercatoris ◽  
Angélique Leonard ◽  
Dominique Toye ◽  
...  
Keyword(s):  
Evaporation Rate ◽  
Crack Formation ◽  
Conventional Tillage ◽  
Small Samples ◽  
Water Evaporation ◽  
Reduced Tillage ◽  
Soil Matrix ◽  
Disturbed Soil ◽  
Micro Cracks ◽  
Crack Dynamics

Crack formation and development have been a general concern in agricultural science. Cracks contribute to soil aeration, aggregate formation, and easy root penetration. However, cracks accelerate soil desiccation, allow deep infiltration of pesticides/pollutants through preferential flow, and pollute the shallow water table in Belgium. Cracks have mostly been studied in pure clay or in high-clay-content soil (Vertisol). Yet, in Wallonia, cracks were also present on silt–loam soil (Luvisol). This study tried to cover this gap by analysing crack dynamics and evaporation process, during drying kinetics of the Luvisol. Soils were collected directly from the agricultural field and processed on a small drying chamber in which an evaporation test took place. A ceramic IR emitter heated the chamber while sensors (DHT22) measured the temperature and relative humidity. A digital camera took photos of the soil surface at 30-min intervals. A balance and tensiometer were linked to a datalogger (CR800), and recorded the soil hydraulic properties (evaporation rate, etc.). Cracks were assessed from small samples (~5 cm × 1cm thick) and big samples (~20 cm size × 1.6 cm thick). Three treatments were considered, including disturbed soil, conventional tillage and reduced tillage. For big samples, results showed higher crack formation on disturbed soil > reduced tillage > conventional tillage, due to loose soil cohesion, soil organic content, soil aggregation, biological activities, and soil porosity. The soil evaporation rate was also greater in disturbed soil > reduced tillage > conventional tillage. Cracks opening exposed a large quantity of soil water to the atmosphere without it passing through the soil matrix. For small samples, the repetitive drying experiments increased cracks’ length and width, especially for the dense samples. The results indicated the presence of pre-existing (or micro-) cracks in the soil samples. Future study is needed to assess the presence of pre- (micro-) cracks in soil using X-ray microtomography.

Effect of Cultural Practices on Weed Control and Crop Response in Imidazolinone-Tolerant Rice

2006 ◽  
Vol 20 (1) ◽  
pp. 249-254 ◽  
Author(s):  
Ronald J. Levy ◽  
Jason A. Bond ◽  
Eric P. Webster ◽  
James L. Griffin ◽  
Steven D. Linscombe
Keyword(s):  
Weed Control ◽  
Seed Weight ◽  
Cultural Practices ◽  
Field Research ◽  
Conventional Tillage ◽  
Reduced Tillage ◽  
Red Rice ◽  
Crop Response ◽  
Tillage Systems ◽  
Seed Harvest

Field research was conducted for 3 yr to evaluate crop response and weed control under conventional and reduced tillage in drill- and water-seeded imidazolinone-tolerant (IT) rice culture. Imazethapyr was applied at 70 g ai/ha PRE followed by (fb) imazethapyr at 70 g/ha applied POST to three- to four-leaf rice or at 105 g/ha PRE fb 70 g/ha POST. In both conventional and reduced tillage systems, imazethapyr applied PRE fb POST at 70 g ai/ha controlled red rice, barnyardgrass, Amazon sprangletop, and rice flatsedge 87 to 99% 35 d after POST treatment (DAT). At 35 DAT, Indian jointvetch control with sequential applications of imazethapyr was as high as 70% in water-seeded rice but no more than 54% in drill-seeded rice. Tillage, seeding method, and imazethapyr rate had no effect on days to 50% heading, seeds per panicle, seed weight per panicle, or percentage of seed harvest. However, a reduction of 27% in days to 50% heading, 80% in seeds per panicle, 84% in seed weight per panicle, and 100% in percentage seed harvest index occurred when imazethapyr was not applied because of weed interference. Culm number was reduced 28%, and culm weight 32% under reduced tillage compared with conventional tillage. With sequential applications of imazethapyr at 70 g/ha, rice yield was 63% greater when rice was water-seeded compared with drill-seeded. No differences in tillage systems for weed control, days to 50% heading, seed number, seed weight per panicle, percent seed, panicle height, lodging, or yield were observed. Results of these experiments demonstrate imazethapyr will effectively control weeds in both water- and drill-seeded rice and that reduced tillage can be used without negatively affecting rice production.

Predicting water retention curves of fine texture soils from particle size distribution

2020 ◽  
Author(s):  
Joseph Pollacco ◽  
Jesús Fernández-Gálvez ◽  
Sam Carrick
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Pore Space ◽  
Water Retention Curve ◽  
Soil Hydraulic Properties ◽  
Retention Curve ◽  
Soil Particles

<p>Indirect methods for estimating soil hydraulic properties from particle size distribution have been developed due to the difficulty in accurately determining soil hydraulic properties, and the fact that particle size distribution is one piece of basic soil physical information normally available. The similarity of the functions describing the cumulative distribution of particle size and pore size in the soil has been the basis for relating particle size distribution and the water retention function in the soil. Empirical and semi-physical models have been proposed, but these are based on strong assumptions that are not always valid. For example, soil particles are normally assumed to be spherical, with constant density regardless of their size; and the soil pore space has been described by an assembly of capillary tubes, or the pore space in the soil matrix is assumed to be arranged in a similar way regardless of particle size. However, in a natural soil the geometry of the pores may vary with the size of the particles, leading to a variable relation between particle radius and pore radius.</p><p> </p><p>The current work is based on the hypothesis that the geometry of the pore size and the void ratio depends on the size of the soil particles, and that a physically based model can be generalised to predict the water retention curve from particle size distribution. The rearrangement of the soil particles is considered by introducing a mixing function that modulates the cumulative particle size distribution, while the total porosity is constrained by the saturated water content.</p><p> </p><p>The model performance is evaluated by comparing the soil water retention curve derived from laboratory measurements with a mean Nash–Sutcliffe model efficiency a value of 0.92 and a standard deviation of 0.08. The model is valid for all soil types, not just those with a marginal clay fraction.</p>

Surface hydraulic properties of a red earth under continuous cropping with different management practices

Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 13 ◽  
Author(s):  
KY Chan ◽  
DP Heenan
Keyword(s):  
Hydraulic Conductivity ◽  
Hydraulic Properties ◽  
Management Practices ◽  
Conventional Tillage ◽  
Wagga Wagga ◽  
Continuous Cropping ◽  
Soil Hydraulic Properties ◽  
Earthworm Population ◽  
Red Earth ◽  
Water Repellence

Differences in surface soil hydraulic properties after 10 years of different tillage (direct drilled (DD) versus conventional tillage (CT)) and stubble management practices (stubble retained (SR) versus stubble burnt (SB)) were measured in a lupin/wheat rotation on a red earth at Wagga Wagga, NSW. Sorptivity and hydraulic conductivity measurements using a disk permeameter under negative matric potential (-40 mrn) was complicated by water repellence found under SR as compared to SB treatments. Using water, K-40 of SR/DD was only 40% of SB/CT. However, using a wetting agent instead of water increased K-40 of SR/DD by >400% but did not significantly change that of SB/CT such that K-40 was similar for the two treatments. Despite similar bulk density, hydraulic conductivity under ponded infiltration of SR/DD was 4.1 times that of SB/CT. Differences in hydraulic conductivity between -40 mm and under ponded conditions suggest the presence of significantly more transmitting macropores >1.5 mm in diameter under direct drilling. Dye infiltration results indicated that tillage significantly reduced the number of transmitting macropores (>1 mm) even though the total number of macropores remained similar amongst the different treatments. 65% of the macropores were transmitting under SR/DD compared to 1% under SB/CT. A significant correlation (r2=0.82**) was found between transmitting pores (>1.0 mm) and the earthworm population. Tillage but not stubble burning significantly reduced earthworm population.

Impact of plant roots and soil organisms on soil micromorphology and hydraulic properties

Biologia ◽  
2006 ◽  
Vol 61 (19) ◽  
Author(s):  
Radka Kodešová ◽  
Vít Kodeš ◽  
Anna Žigová ◽  
Jiří Šimůnek
Keyword(s):  
Pore Structure ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Water Retention Curve ◽  
Soil Organisms ◽  
Soil Hydraulic Properties ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
The Impact

AbstractA soil micromorphological study was performed to demonstrate the impact of soil organisms on soil pore structure. Two examples are shown here. First, the influence of earthworms, enchytraeids and moles on the pore structure of a Greyic Phaeozem is demonstrated by comparing two soil samples taken from the same depth of the soil profile that either were affected or not affected by these organisms. The detected image porosity of the organism-affected soil sample was 5 times larger then the porosity of the not-affected sample. The second example shows macropores created by roots and soil microorganisms in a Haplic Luvisol and subsequently affected by clay coatings. Their presence was reflected in the soil water retention curve, which displayed multiple S-shaped features as obtained from the water balance carried out for the multi-step outflow experiment. The dual permeability models implemented in HYDRUS-1D was applied to obtain parameters characterizing multimodal soil hydraulic properties using the numerical inversion of the multi-step outflow experiment.

scholarly journals Assessing the cover crop effect on soil hydraulic properties by inverse modelling in a 10-year field trial

2018 ◽  
Author(s):  
José Luis Gabriel ◽  
Miguel Quemada ◽  
Diana Martín-Lammerding ◽  
Marnik Vanclooster
Keyword(s):  
Soil Water ◽  
Cover Crop ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Soil Hydraulic Properties ◽  
Cover Cropping ◽  
Term Change ◽  
Soil Hydraulic ◽  
The Impact

Abstract. Cover cropping in agriculture is expected to enhance many agricultural and ecosystems functions and services. Yet, few studies are available allowing to evaluate the impact of cover cropping on the long term change of soil hydrologic functions. We assessed the long term change of the soil hydraulic properties due to cover cropping by means of a 10-year field experiment. We monitored continuously soil water content in non cover cropped and cover cropped fields by means of capacitance probes. We subsequently determined the hydraulic properties by inverting the soil hydrological model WAVE, using the time series of the 10 year monitoring data in the object function. We observed two main impacts, each having their own time dynamics. First, we observed an initial compaction as a result of the minimum tillage. This initial negative effect was followed by a more positive cover crop effect. The positive cover crop effect consisted in an increase of the soil micro- and macro-porosity, improving the structure. This resulted in a larger soil water retention capacity. This latter improvement was mainly observed below 20 cm, and mostly in the soil layer between 40 and 80 cm depth. This study shows that the expected cover crop competition for water with the main crop can be compensated by an improvement of the water retention in the intermediate layers of the soil profile. This may enhance the hydrologic functions of agricultural soils in arid and semiarid regions which often are constrained by water stress.

scholarly journals A global data set of soil hydraulic properties and sub-grid variability of soil water retention and hydraulic conductivity curves

2017 ◽  
Vol 9 (2) ◽  
pp. 529-543 ◽  
Author(s):  
Carsten Montzka ◽  
Michael Herbst ◽  
Lutz Weihermüller ◽  
Anne Verhoef ◽  
Harry Vereecken
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Texture ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Climate Models ◽  
Hydraulic Parameters ◽  
Soil Hydraulic Properties ◽  
Soil Water Retention ◽  
Data Set ◽  
Global Data

Abstract. Agroecosystem models, regional and global climate models, and numerical weather prediction models require adequate parameterization of soil hydraulic properties. These properties are fundamental for describing and predicting water and energy exchange processes at the transition zone between solid earth and atmosphere, and regulate evapotranspiration, infiltration and runoff generation. Hydraulic parameters describing the soil water retention (WRC) and hydraulic conductivity (HCC) curves are typically derived from soil texture via pedotransfer functions (PTFs). Resampling of those parameters for specific model grids is typically performed by different aggregation approaches such a spatial averaging and the use of dominant textural properties or soil classes. These aggregation approaches introduce uncertainty, bias and parameter inconsistencies throughout spatial scales due to nonlinear relationships between hydraulic parameters and soil texture. Therefore, we present a method to scale hydraulic parameters to individual model grids and provide a global data set that overcomes the mentioned problems. The approach is based on Miller–Miller scaling in the relaxed form by Warrick, that fits the parameters of the WRC through all sub-grid WRCs to provide an effective parameterization for the grid cell at model resolution; at the same time it preserves the information of sub-grid variability of the water retention curve by deriving local scaling parameters. Based on the Mualem–van Genuchten approach we also derive the unsaturated hydraulic conductivity from the water retention functions, thereby assuming that the local parameters are also valid for this function. In addition, via the Warrick scaling parameter λ, information on global sub-grid scaling variance is given that enables modellers to improve dynamical downscaling of (regional) climate models or to perturb hydraulic parameters for model ensemble output generation. The present analysis is based on the ROSETTA PTF of Schaap et al. (2001) applied to the SoilGrids1km data set of Hengl et al. (2014). The example data set is provided at a global resolution of 0.25° at https://doi.org/10.1594/PANGAEA.870605.

Measurement of soil hydraulic properties of structured and repacked soils

2021 ◽  
Author(s):  
Urša Pečan ◽  
Luka Žvokelj ◽  
Jure Ferlin ◽  
Vesna Zupanc ◽  
Marina Pintar
Keyword(s):  
Soil Water ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Soil Samples ◽  
Measuring System ◽  
Soil Hydraulic Properties ◽  
Soil Water Retention ◽  
Undisturbed Soil ◽  
Soil Hydraulic ◽  
Low Tension

<p>Soil hydraulic properties provide important information about soil behavior under unsaturated and saturated conditions. Often sampling of undisturbed soils is not possible and soil samples have to be repacked for laboratory analysis. The HYPROP® measuring system (METERgroup, Munich, Germany) is a convenient method for determination of soil water retention characteristics and unsaturated hydraulic conductivity of undisturbed soil samples. It measures the matric potential of the saturated and drying soil sample using two tensiometers placed at different depths. Although the tensiometers are based on a new design that theoretically withstands cavitation at higher tension values, they are still considered to operate in the low tension range. Since soil water retention properties in the low tension range are strongly influenced by soil structure and pore size distribution, we were interested in the changes in hydraulic properties when measured on disturbed and then repacked samples, and undisturbed soil samples. Therefore, we investigated the soil hydraulic properties of three different soil types using the evaporation method on undisturbed and repacked samples. The results provide important insights for the interpretation of the results when the collection of undisturbed samples is not possible, and for designing laboratory experiments with repacked soils.</p>

scholarly journals Further tests of the HYPROP evaporation method for estimating the unsaturated soil hydraulic properties

2018 ◽  
Vol 66 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Camila R. Bezerra-Coelho ◽  
Luwen Zhuang ◽  
Maria C. Barbosa ◽  
Miguel Alfaro Soto ◽  
Martinus Th. van Genuchten
Keyword(s):  
Hydraulic Conductivity ◽  
Unsaturated Soil ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Measurement Techniques ◽  
Richards Equation ◽  
Water Retention Curve ◽  
Soil Hydraulic Properties ◽  
Evaporation Method ◽  
Soil Hydraulic

AbstractMany soil, hydrologic and environmental applications require information about the unsaturated soil hydraulic properties. The evaporation method has long been used for estimating the drying branches of the soil hydraulic functions. An increasingly popular version of the evaporation method is the semi-automated HYPROP©measurement system (HMS) commercialized by Decagon Devices (Pullman, WA) and UMS AG (München, Germany). Several studies were previously carried out to test the HMS methodology by using the Richards equation and the van-Genuchten-Mualem (VG) or Kosugi-Mualem soil hydraulic functions to obtain synthetic data for use in the HMS analysis, and then to compare results against the original hydraulic properties. Using HYDRUS-1D, we carried out independent tests of the HYPROP system as applied to the VG functions for a broad range of soil textures. Our results closely agreed with previous findings. Accurate estimates were especially obtained for the soil water retention curve and its parameters, at least over the range of available retention measurements. We also successfully tested a dual-porosity soil, as well as an extremely coarse medium with a very high van Genuchtennvalue. The latter case gave excellent results for water retention, but failed for the hydraulic conductivity. In many cases, especially for soils with intermediate and highnvalues, an independent estimate of the saturated hydraulic conductivity should be obtained. Overall, the HMS methodology performed extremely well and as such constitutes a much-needed addition to current soil hydraulic measurement techniques.

Testing an infiltrometer methodology to investigate water impact effects on both soil sealing and hydraulic properties of a loam soil under conventional tillage and no-tillage

2020 ◽  
Author(s):  
Mirko Castellini ◽  
Simone Di Prima ◽  
Anna Maria Stellacci ◽  
Massimo Iovino ◽  
Vincenzo Bagarello
Keyword(s):  
Hydraulic Conductivity ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Soil Management ◽  
Water Retention Curve ◽  
Soil Hydraulic Properties ◽  
Retention Curve ◽  
Soil Sealing ◽  
Loam Soil ◽  
Soil Hydraulic

<p>Testing new experimental procedures to assess the effects of the drops impact on the soil sealing formation is a main topic in soil hydrology.</p><p>In this field investigation, the methodological approach proposed first by Bagarello et al. (2014) was extended to account for a greater soil infiltration surface (i.e., about 3.5 times higher), a higher range and number of heights of water pouring and to evaluate the different impact on soil management. For this purpose, the effects of three water pouring heights (low, L=3 cm; medium, M=100 cm; high, H=200 cm) on both no-tilled (NT) and conventionally tilled (CT) loam soil were investigated by Beerkan infiltration runs and using the BEST-procedure of data analysis to estimate the soil hydraulic properties.</p><p>Final infiltration rate decreased when perturbing runs (i.e., M and H) were carried out as compared with the non-perturbing (L) ones (by a factor of 1.5-3.1 under NT and 3.4-4.4 under CT). Similarly, the water retention scale parameter, h<sub>g</sub>, increased (i.e., higher in absolute terms) by a factor 1.6-1.8 under NT and by a factor 1.7 under CT. Saturated hydraulic conductivity, K<sub>s</sub>, changed significantly as a function of the increase of water pouring height; regardless of the soil management, perturbing runs caused a reduction in soil permeability by a factor 5 or 6. Effects on hydraulic functions (i.e., soil water retention curve and hydraulic conductivity function), obtained with the BEST-Steady algorithm, were also highlighted. For instance, differences in water retention curve at fixed soil pressure head values (i.e., field capacity, FC, and permanent wilting point, PWP) due to perturbing and non-perturbing runs, were estimated as higher under NT (3.8%) than CT (3.4%) for FC, and equal to 2.1% or 1.6% for PWP.</p><p>Main results of this investigation confirm that a recently tilled loamy soil, without vegetation cover, can be less resilient as compared to a no-tilled one, and that tested water pouring heights methodology looks promising to mimic effects of high energy rainfall events and to quantify the soil sealing effects under alternative management of the soil.</p><p><strong>Acknowledgments</strong></p><p>The work was supported by the project “STRATEGA, Sperimentazione e TRAsferimento di TEcniche innovative di aGricoltura conservativA”, funded by Regione Puglia–Dipartimento Agricoltura, Sviluppo Rurale ed Ambientale, CUP: B36J14001230007.</p><p><strong> </strong><strong>References</strong></p><p>Bagarello, V., Castellini, M., Di Prima, S., Iovino, M. 2014. Soil hydraulic properties determined by infiltration experiments and different heights of water pouring. Geoderma, 213, 492–501. https://doi.org/10.1016/j.geoderma.2013.08.032</p>

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