scholarly journals CONDUTIVIDADE HIDRÁULICA E DRENAGEM INTERNA EM LATOSSOLO CULTIVADO COM CAFÉ ADUBADO COM ELEVADAS DOSES DE NITROGÊNIO

Irriga ◽  
2018 ◽  
Vol 23 (4) ◽  
pp. 835-843
Author(s):  
Mateus de Paula Gomes ◽  
Genelício Cruzoé Rocha ◽  
José Adinan Souza ◽  
Carlos Henriques Silva Rezende
Keyword(s):  
Hydraulic Conductivity ◽  
Additional Treatment ◽  
Water Retention Curve ◽  
Internal Drainage ◽  
Soil Drainage ◽  
High Nitrogen ◽  
Retention Curve ◽  
Unsaturated Hydraulic Conductivity ◽  
High Doses ◽  
E Mail

CONDUTIVIDADE HIDRÁULICA E DRENAGEM INTERNA EM LATOSSOLO CULTIVADO COM CAFÉ ADUBADO COM ELEVADAS DOSES DE NITROGÊNIO     MATEUS DE PAULA GOMES1; GENELÍCIO CRUSOÉ ROCHA2; JOSÉ ADINAN SOUZA3 E CARLOS HENRIQUES SILVA REZENDE1   1 Departamento de Solos - Universidade Federal de Viçosa - Avenida Peter Henry Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brasil. E-mail: [email protected] 2 Departamento de Solos - Universidade Federal de Viçosa - Avenida Peter Henry Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brasil. E-mail: [email protected] 3 Departamento de Solos - Universidade Federal de Viçosa - Avenida Peter Henry Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brasil. E-mail: [email protected] 4 Departamento de Solos - Universidade Federal de Viçosa - Avenida Peter Henry Rolfs, s/n, Campus Universitário, 36570-900 Viçosa, MG, Brasil. E-mail: [email protected]     1 RESUMO   O uso de altas doses de fertilizantes favorece o desenvolvimento vegetal e dos microrganismos do solo que podem modificar o processo de drenagem interna. O objetivo deste estudo foi avaliar a drenagem interna e a condutividade hidráulica de um Latossolo cultivado com café fertilizado com doses elevadas de nitrogênio. O delineamento experimental foi o de blocos casualizados, em esquema fatorial (3 × 2) + 1, sendo três doses de nitrogênio, duas formas de ureia e um tratamento adicional sem aplicação nitrogenada. A condutividade hidráulica não saturada foi obtida em laboratório por meio da curva de retenção de água no solo e no campo por meio do Mini Disk Infiltrometer. Os resultados foram submetidos à análise de variância e foram ajustados modelos de regressão para o efeito das doses de N na condutividade hidráulica do solo. Observou-se que acúmulos na precipitação acarretam em aumentos lineares na drenagem interna do solo. O aumento da dose de nitrogênio não influenciou na condutividade hidráulica saturada e não-saturada, nem na drenagem interna.   Palavras-chave: água no solo, estrutura do solo, fluxo de água.     GOMES, M. P.; ROCHA, G. C.; SOUZA, J. A.; REZENDE, C. H. S. HYDRAULIC CONDUCTIVITY AND INTERNAL DRAINAGE IN A LATOSOIL CULTIVATED WITH COFFEE FERTILIZED IN HIGH NITROGEN DOSES     2 ABSTRACT   The use of high doses of fertilizers favors plant development and soil microorganisms that can modify the internal drainage process. The objective of this study was to evaluate the internal drainage and hydraulic conductivity of an Oxisol cultivated with coffee fertilized in high nitrogen doses. The experimental design was based on randomized blocks, in a factorial scheme (3 × 2) 1, with three nitrogen doses, two urea forms and one additional treatment with no nitrogen application. The unsaturated hydraulic conductivity was obtained in the laboratory by means of the water retention curve in the soil and in the field, through the Mini Disk Infiltrometer. The results were submitted to a variance analysis and regression models were adjusted for the effect of N doses on soil hydraulic conductivity. It was possible to observe that accumulations in precipitation lead to linear increases in internal soil drainage. Increasing the nitrogen dose did not influence neither the saturated and unsaturated hydraulic conductivity nor the internal drainage.   Keywords: soil water, soil structure, water flow.

scholarly journals Simultaneous Determination of Water Retention Curve and Unsaturated Hydraulic Conductivity of Substrates Using a Steady-state Laboratory Method

HortScience ◽  
2010 ◽  
Vol 45 (7) ◽  
pp. 1106-1112 ◽  
Author(s):  
Paraskevi A. Londra
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Hydraulic Conductivity ◽  
Water Retention ◽  
Water Pressure ◽  
Pressure Head ◽  
Laboratory Method ◽  
Water Retention Curve ◽  
Retention Curve ◽  
Unsaturated Hydraulic Conductivity

For effective irrigation and fertilization management, the knowledge of substrate hydraulic properties is essential. In this study, a steady-state laboratory method was used to determine simultaneously the water retention curve, θ(h), and unsaturated hydraulic conductivity as a function of volumetric water content, K(θ), and water pressure head, K(h), of five substrates used widely in horticulture. The substrates examined were pure peat, 75/25 peat/perlite, 50/50 peat/perlite, 50/50 coir/perlite, and pure perlite. The experimental retention curve results showed that in the case of peat and its mixtures with perlite, there is a hysteresis between drying and wetting branches of the retention curve. Whereas in the case of coir/perlite and perlite, the phenomenon of hysteresis was less pronounced. The increase of perlite proportion in the peat/perlite mixtures led to a decrease of total porosity and water-holding capacity and an increase of air space. Study of the K(θ) and K(h) experimental data showed that the hysteresis phenomenon of K(θ) was negligible compared with the K(h) data for all substrates examined. Within a narrow range of water pressure head (0 to –70 cm H2O) that occurs between two successive irrigations, a sharp decrease of the unsaturated hydraulic conductivity was observed. The comparison of the K(θ) experimental data between the peat-based substrate mixtures and the coir-based substrate mixture showed that for water contents lower than 0.40 m3·m−3, the hydraulic conductivity of the 50/50 coir/perlite mixture was greater. The comparison between experimental water retention curves and predictions using Brooks-Corey and van Genuchten models showed a high correlation (0.992 ≤ R2 ≤ 1) for both models for all substrates examined. On the other hand, in the case of unsaturated hydraulic conductivity, the comparison showed a relatively good correlation (0.951 ≤ R2 ≤ 0.981) for the van Genuchten-Mualem model for all substrates used except perlite and a significant deviation (0.436 ≤ R2 ≤ 0.872) for the Brooks-Corey model for all substrates used.

scholarly journals Effect of Chia Seed Mucilage on the Rhizosphere Hydraulic Characteristics

2021 ◽  
Vol 13 (6) ◽  
pp. 3303
Author(s):  
Faisal Hayat ◽  
Mohanned Abdalla ◽  
Muhammad Usman Munir
Keyword(s):  
Hydraulic Conductivity ◽  
Hydraulic Properties ◽  
Water Retention ◽  
Numerical Models ◽  
Chemical Properties ◽  
Water Retention Curve ◽  
Soil Drying ◽  
Retention Curve ◽  
Unsaturated Hydraulic Conductivity ◽  
Chia Seed

The rhizosphere is one of the major components in the soil–plant–atmosphere continuum which controls the flow of water from the soil into roots. Plant roots release mucilage in the rhizosphere which is capable of altering the physio-chemical properties of this region. Here, we showed how mucilage impacted on rhizosphere hydraulic properties, using simple experiments. An artificial rhizosphere, treated or not with mucilage, was placed in a soil sample and suction was applied to mimic the negative pressure in plant xylem. The measured water contents and matric potential were coupled with numerical models to estimate the water retention curve and hydraulic conductivity. A slower loss of water was observed in the treated scenario which resulted in an increase in water retention. Moreover, a slightly lower hydraulic conductivity was initially observed in the treated scenario (8.44 × 10−4 cm s−1) compared to the controlled one in saturated soil. Over soil drying, a relatively higher unsaturated hydraulic conductivity was observed. In summary, we demonstrated that mucilage altered the rhizosphere hydraulic properties and enhanced the unsaturated hydraulic conductivity. These findings improve our understanding of how plants capture more water, and postulate that mucilage secretion could be an optimal trait for plant survival during soil drying.

scholarly journals ANÁLISE COMPARATIVA DA CARACTERIZAÇÃO FÍSICO –HÍDRICA DE UM LATOSSOLO VERMELHO DISTRÓFICO IN SITU E EM LABORATÓRIO

Irriga ◽  
2005 ◽  
Vol 10 (1) ◽  
pp. 1-19 ◽  
Author(s):  
Polyanna Mara de Oliveira ◽  
Antônio Marciano da Silva ◽  
Gilberto Coelho ◽  
Ricardo Augusto da Silva
Keyword(s):  
Hydraulic Conductivity ◽  
Field Capacity ◽  
Field Conditions ◽  
Water Retention Curve ◽  
Moisture Determination ◽  
Internal Drainage ◽  
Retention Curve ◽  
Laboratory Conditions ◽  
Field And Laboratory Conditions

ANÁLISE COMPARATIVA DA CARACTERIZAÇÃO FÍSICO –HÍDRICA DE UM LATOSSOLO VERMELHO DISTRÓFICO IN SITU E EM LABORATÓRIO  Polyanna Mara de Oliveira; Antônio Marciano da Silva; Gilberto Coelho; Ricardo Augusto da SilvaDepartamento de Engenharia, Universidade Federal de Lavras ,Caixa Postal 37, CEP 37200-000, , Lavras, MG,  [email protected]  1 RESUMO Neste trabalho estudaram-se métodos para a estimativa da umidade representativa da capacidade de campo e da condutividade hidráulica não saturada para o Latossolo Vermelho Distrófico, trabalhando com dois métodos, o de perfil instantâneo (HILLEL et al., 1972) e o método empírico de Mualem (1976). Em laboratório foram realizadas a análise granulométrica, densidade do solo, porosidade (macro e microporosidade) e a curva característica de retenção, e em campo, determinaram-se a umidade na capacidade de campo e a condutividade hidráulica. Os resultados encontrados permitem afirmar que a caracterização físico-hídrica do solo em condições de campo mostrou-se mais precisa e confiável em relação às determinações de laboratório sendo que a estimativa da condutividade hidráulica mostrou-se mais consistente com outros atributos do solo e mais representativa da realidade do que aquela baseada em análises laboratoriais. Embora a metodologia de Mualem (1976) possa ser aplicada desde a umidade de saturação até o ponto de murcha permanente, a mesma não mostrou sensibilidade para registrar a influência da macroporosidade sobre a condutividade hidráulica do solo. A estimativa da umidade na capacidade de campo “in situ” ratifica também a melhor performance do método de campo em relação ao laboratorial. UNITERMOS: condutividade hidráulica, capacidade de campo, curva de retenção de água, drenagem interna do solo, atributos físicos do solo.  OLIVEIRA, P. M. de; SILVA, A. M. da; COELHO, G.; SILVA, R. A. COMPARATIVE ANALYSE OF THE PHYSICAL AND WATER CHARACTERIZATION IN FIELD AND LABORATORY CONDITIONS OF DISTROFIC RED LATOSSOL  2 ABSTRACT The aim of this work was to study methods to determine significant moisture for field capacity and non-saturated hydraulic conductivity in dystrophic latossol soil using two methods: internal drainage method (Hillel et al., 1972) and empiric method (Mualem, 1976). Granulometric analysis, soil density, porosity (macro and micro porosity) and characteristic retention curve were determined in laboratory; moisture for field capacity and hydraulic conductivity were determined in field conditions. The results showed that physical and hydraulic soil characterization in field conditions is more accurate and reliable than in lab conditions; hydraulic conductivity determination infield conditions was more consistent with other soil attributes and more realistic than the one based on laboratory conditions. Although Mualem’s method (1979) may be used for saturation moisture as well as for permanent internal drainage, it has not presented the same sensitivity to determine the influence of macro porosity on soil hydraulic conductivity. Moisture determination for field capacity under field conditions also corroborates better performance for field methods than laboratory ones.  KEYWORDS: hydraulic conductivity, field capacity, water retention curve, soil internal drainage, soil physical properties 

Weighting the differential water capacity to account for declining hydraulic conductivity in a drying coarse-textured soil

Soil Research ◽  
2015 ◽  
Vol 53 (4) ◽  
pp. 386 ◽  
Author(s):  
C. D. Grant ◽  
P. H. Groenevelt
Keyword(s):  
Hydraulic Conductivity ◽  
Water Availability ◽  
Water Retention ◽  
Water Retention Curve ◽  
Weighting Coefficient ◽  
Evaporative Demand ◽  
Retention Curve ◽  
Water Capacity ◽  
Unsaturated Hydraulic Conductivity ◽  
Starting Point

Water availability to plants growing in coarse-textured soils during a drying cycle relies on the declining abilities of the soil to release water (differential water capacity) and to deliver it to the plant (unsaturated hydraulic conductivity) under varying evaporative demand. In this context, the availability of water can be quantified using the concept of the integral water capacity, IWC, in which the differential water capacity is weighted by means of a restrictive hydraulic function before integrating. We argue here that the diffusivity is an appropriate component of the restrictive hydraulic function, which leads to the employment of the so-called ‘matric flux potential’ (which we propose to re-name as the ‘matric flux transform’). As the starting point to apply the diffusivity function, we choose the inflection point of the water-retention curve drawn on semi-log paper, which, for the Groenevelt–Grant equation, occurs at a matric head, h, of precisely k0 metres. An illustrative example of the procedures is provided for a coarse-textured soil, which reveals that the restrictive function may not be sufficiently restrictive for all cases. We therefore apply an additional weighting coefficient to account for varying sensitivity of different plants to hydraulic restrictions.

scholarly journals Effect of fine particles on the hydraulic behavior of interlayer soil in railway substructure

2014 ◽  
Vol 51 (7) ◽  
pp. 735-746 ◽  
Author(s):  
Trong Vinh Duong ◽  
Yu-Jun Cui ◽  
Anh Minh Tang ◽  
Jean-Claude Dupla ◽  
Nicolas Calon
Keyword(s):  
Hydraulic Conductivity ◽  
Water Content ◽  
Fine Particles ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Retention Curve ◽  
Hydraulic Behavior ◽  
Unsaturated Hydraulic Conductivity ◽  
Railway Substructure

The conventional railway substructure in France was built by emplacing ballast directly on subgrade. Over years of operation, the interpenetration of ballast and subgrade created a soil layer between them. Under different conditions, this naturally formed layer, namely interlayer, can contain different quantities of fine particles, becoming more or less sensitive to changes in water content. As the water content changes are governed by the hydraulic behavior of the interlayer soil, assessing the influence of fine particle content on the hydraulic behavior of interlayer soil is of importance. To this end, the hydraulic behavior of an interlayer soil taken from Sénissiat (near Lyon, France) was investigated using two infiltration columns, a large-scale column equipped with tensiometers and a time domain reflectometer (TDR) for suction and volumetric water content measurements, respectively, and a smaller column equipped with high-capacity tensiometers only. Different fines contents were considered and wetting–drying cycles were applied to the soil specimens. The hydraulic conductivity was determined by applying the instantaneous profile method. The results obtained showed that (i) hysteresis exists for both the soil water retention curve and the hydraulic conductivity changes with suction; (ii) the effect of wetting–drying cycles is insignificant; (iii) adding 10% fine particles to the natural interlayer soil gives rise to changes in the soil water retention curve but does not induce significant changes in hydraulic conductivity; (iv) the unsaturated hydraulic conductivity of interlayer soil with 10% fine particles added is close to that of soil sieved at 2 mm, suggesting that the unsaturated hydraulic conductivity of interlayer soil is mainly governed by fine particles through the suction effect. By contrast, in a saturated state, the value for the interlayer soil with 10% fine particles added was found to be higher, suggesting that in this case the hydraulic conductivity is mainly governed by the water transfer through macropores.

Predicting the unsaturated hydraulic conductivity of granular soils from basic geotechnical properties using the modified Kovács (MK) model and statistical models

2006 ◽  
Vol 43 (8) ◽  
pp. 773-787 ◽  
Author(s):  
M Mbonimpa ◽  
M Aubertin ◽  
B Bussière
Keyword(s):  
Hydraulic Conductivity ◽  
Statistical Models ◽  
Unsaturated Soils ◽  
Water Retention ◽  
Geotechnical Properties ◽  
Water Retention Curve ◽  
Granular Soils ◽  
Retention Curve ◽  
Unsaturated Hydraulic Conductivity ◽  
Preliminary Validation

The water retention curve (WRC) is often used to define the relative hydraulic conductivity, kr, of unsaturated soils. In this paper, the authors propose the use of the modified Kovács (MK) model, developed to predict the WRC using basic geotechnical properties, combined with some existing statistical models to estimate the kr function. The proposed equations are implemented in MATLAB®. After a preliminary validation based on comparisons with existing solutions, predictive results are presented for granular soils. These indicate a relatively good agreement with experimental results from drainage tests taken from the literature. A discussion follows on the advantages and limitations of the proposed approach.Key words: water retention curve, unsaturated hydraulic conductivity, predictive models, granular soils.

scholarly journals A numerical study on the effect of salinity on stability of an unsaturated railway embankment under rainfall

2020 ◽  
Vol 195 ◽  
pp. 01004
Author(s):  
Ali Kolahdooz ◽  
Hamed Sadeghi ◽  
Mohammad Mehdi Ahmadi
Keyword(s):  
Hydraulic Conductivity ◽  
Soil Water ◽  
Water Retention ◽  
Numerical Study ◽  
Water Retention Curve ◽  
Soil Water Retention Curve ◽  
Soil Water Retention ◽  
Unsaturated Hydraulic Conductivity ◽  
Influence Of Water ◽  
Dispersive Soils

Dispersive soils, as one of the main categories of problematic soils, can be found in some parts of the earth, such as the eastern-south of Iran, nearby the Gulf of Oman. One of the most important factors enhancing the dispersive potential is the existence of dissolved salts in the soil water. The main objective of this study is to explore the influence of water salinity on the instability of a railway embankment due to rainfall infiltration. In order to achieve this goal, the embankment resting on a dispersive stratum is numerically modeled and subjected to transient infiltration flow. The effect of dispersion is simplified through variations in the soil-water retention curve with salinity. The measured water retention curves revealed that by omitting the natural salinity in the soil-water, the retention capability of the soil decreases; therefore, the unsaturated hydraulic conductivity of the soil stratum will significantly decline. According to the extensive decrease in the hydraulic conductivity of the desalinated materials, the rainfall cannot infiltrate in the embankment and the rainfall mostly runs off. However, in the saline embankment, the infiltration decreases the soil suction; and consequently, the factor of safety of the railway embankment decreases.

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