Pressure-Plate Apparatus for Measuring Moisture Sorption and Transmission by Soils

Richards, L. A.; Fireman, Milton

doi:10.1097/00010694-194312000-00001

Cited by 199 publications

(110 citation statements)

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“…The soil water-holding capacity was determined in a tension table and Richards' extractor device (Richards and Fireman, 1943), which allowed for the construction of a water-retention curve and determination of soil water potential (ψ w ). During the first 45 DAE, plants received water daily to maintain the ψ w at -13 kPa (300 mL of water per L of soil), which represents a fraction of available water (FAW) of 0.9.…”

Section: Methodsmentioning

confidence: 99%

Water restriction and physiological traits in soybean genotypes contrasting for nitrogen fixation drought tolerance

Cerezini

Fagotti

Pípolo

et al. 2017

Sci. agric. (Piracicaba, Braz.)

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Biological nitrogen fixation (BNF) is essential to the economic viability of the soybean [Glycine max (L.) Merrill] crop in Brazil, but drought may impair the BNF processes. We evaluated physiological traits of nitrogen fixation drought-tolerant (NFDT) (R01-581F, R01-416F and R02-1325) and drought-susceptible (CD 215 and BRS 317) genotypes of soybean subjected to drought or regular water supply between 45 and 55 days after emergence, in an experiment under greenhouse conditions in pots containing non-sterile soil. R01-581F had more stable photosynthetic and transpiration rates, and higher intercellular CO 2 levels under drought. Drought reduced the chlorophyll concentration in all genotypes, but with less intensity in R01-581F and R02-1325. The NFDT genotypes generally showed higher concentrations of N, K and Mn in shoots, irrespective of the water condition. Exposure to drought increased total soluble sugars in nodules in all genotypes, as well as the concentrations of ureides in leaves and nodules, whereas ureides in petioles increased only in the susceptible genotypes. Drought negatively affected photosynthetic and BNF attributes; however, R01-581F showed the best performance, with potential for use in breeding programs aiming at drought-tolerant varieties.

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Section: Methodsmentioning

confidence: 99%

Water restriction and physiological traits in soybean genotypes contrasting for nitrogen fixation drought tolerance

Cerezini

Fagotti

Pípolo

et al. 2017

Sci. agric. (Piracicaba, Braz.)

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“…The samples were collected from soil horizons A (0−0.17 m), B (0.17−0.50 m), Bt1 (0.50−0.80 m), and Bt2 (0.80−1.20 m). Table 1 presents the soil physical attributes, which were determined according to methods recommended in the literature (RICHARDS; FIREMAN, 1943;FLINT;FLINT, 2002;GEE;GROSSMAN;REINSCH, 2002). The physical analyses were conducted at the Laboratory of Soil Physics, of the Federal University of Reconcavo of Bahia.…”

Section: Methodsmentioning

confidence: 99%

Models for moisture estimation in different horizons of yellow argisol using TDR

Almeida

Souza

Paz

et al. 2017

SCA

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The determination of soil moisture is very important because it is the property with the most influence on the dielectric constant of the medium. Time-domain reflectometry (TDR) is an indirect technique used to estimate the water content of the soil (θ) based on its dielectric constant (Ka). Like any other technique, it has advantages and disadvantages. Among the major disadvantages is the need for calibration, which requires consideration of the soil characteristics. This study aimed to perform the calibration of a TDR100 device to estimate the volumetric water content of four horizons of a Yellow Argisol. Calibration was performed under laboratory conditions using disturbed soil samples contained in PVC columns. The three rods of the handcrafted probes were vertically installed in the soil columns. Weight measurements with digital scales and daily readings of the dielectric constant with the TDR device were taken. For all soil horizons evaluated, the best fits between the dielectric constant and the volumetric water content were related to the cubic polynomial model. The Ledieu model overestimated by approximately 68 % the volumetric water content in the A and AB horizons, and underestimating by 69 % in Bt2, in relation to volumetric water content obtained by gravimetry. The underestimation by linear, Topp, Roth, and Malicki models ranged from 50 % to 85 % for all horizons. Key words: Apparent dielectric constant. Soil water content. TDR calibration. ResumoA reflectometria no domínio do tempo (Time Domain Reflectometry, TDR) é uma técnica indireta usada para estimar o conteúdo de água do solo (θ) em função da constante dielétrica (Ka). As vantagens do uso desta técnica são, no entanto, requer calibração específica para cada tipo de solo. Neste estudo objetivou-se realizar a calibração de modelos para estimar a umidade volumétrica de quatro horizontes de um Argissolo Amarelo com uso da TDR. A calibração foi realizada em condições de laboratório utilizando amostras deformadas do solo em estudo, acondicionadas em colunas de PVC. As sondas fabricadas artesanalmente com três hastes foram instaladas verticalmente nas colunas de solo. Foram realizadas pesagens com balança de precisão e leituras diárias da constante dielétrica com o equipamento TDR. Os modelos polinomial cúbico e linear foram os que apresentaram melhor ajuste aos dados de umidade observados. Os modelos de Topp et al. (1980), Ledieu et al. (1986), Malicki et al. (1996) e Roth et al. (1990 superestimaram em aproximadamente 15% as médias de umidade nos horizontes A e AB e subestimam em aproximadamente 18% no Bt2. No horizonte Bt1 todos os modelos foram semelhantes entre si. Palavras-chave: Constante dielétrica aparente. Conteúdo de água no solo. Calibração de TDR.

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“…Using disturbed samples minimises the difficulties of establishing optimum contact between the plate and the sample, thus eliminating measurement variations caused by structural differences in the samples and allowing for the extrapolation of results to samples with similar textures (Lal, 1979). Richards & Fireman (1943) dissented from this approach in tests of dry and wet samples whose structure was disturbed either manually or by sieving. Yet, in our research disturbed samples were used, based on previous studies for the same area (Cancela, 2004;Martínez, 2008).…”

Section: Laboratory Analysis Techniquesmentioning

confidence: 99%

“…The methods used to quantify soil hydraulic properties can be divided into: i) determination with pressure plate (PP) (Richards & Fireman, 1943;Tormena et al, 1998) or WP4 water activity meters (WAMs) (Gee et al, 1992;Albuquerque et al, 2005;Martínez, 2008) and ii) estimation with pedotransfer functions (PTF) (Bouma, 1989;McBratney et al, 2002) or software applications (Donatelli et al, 1996;Acutis & Donatelli, 2003). defined a concept of efficiency and developed it in later research (Minasny et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

The efficiency of different estimation methods of hydro-physical limits

Martínez¹,

García²,

Cancela³

2012

Rev. Bras. Ciênc. Solo

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SUMMARYThe soil water available to crops is defined by specific values of water potential limits. Underlying the estimation of hydro-physical limits, identified as permanent wilting point (PWP) and field capacity (FC), is the selection of a suitable method based on a multi-criteria analysis that is not always clear and defined. In this kind of analysis, the time required for measurements must be taken into consideration as well as other external measurement factors, e.g., the reliability and suitability of the study area, measurement uncertainty, cost, effort and labour invested. In this paper, the efficiency of different methods for determining hydro-physical limits is evaluated by using indices that allow for the calculation of efficiency in terms of effort and cost. The analysis evaluates both direct determination methods (pressure plate -PP and water activity meter -WAM) and indirect estimation methods (pedotransfer functions -PTFs). The PTFs must be validated for the area of interest before use, but the time and cost associated with this validation are not included in the cost of analysis. Compared to the other methods, the combined use of PP and WAM to determine hydro-physical limits differs significantly in time and cost required and quality of information. For direct methods, increasing sample size significantly reduces cost and time. This paper assesses the effectiveness of combining a general analysis based on efficiency indices and more specific analyses based on the different influencing factors, which were considered separately so as not to mask potential benefits or drawbacks that are not evidenced in efficiency estimation.Index terms: field capacity, permanent wilting point, pedotransfer functions, water activity meter.(1) Received for publication in January 24, 2011 and approved in September 25, 2012.

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Pressure-Plate Apparatus for Measuring Moisture Sorption and Transmission by Soils

Cited by 199 publications

References 0 publications

Water restriction and physiological traits in soybean genotypes contrasting for nitrogen fixation drought tolerance

Water restriction and physiological traits in soybean genotypes contrasting for nitrogen fixation drought tolerance

Models for moisture estimation in different horizons of yellow argisol using TDR

The efficiency of different estimation methods of hydro-physical limits

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