Simple Model to Estimate Field-Measured Soilwater Limits

Ritchie, J. T.; Gerakis, Argyrios; Suleiman, Ayman

doi:10.13031/2013.13326

Cited by 98 publications

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“…Overall, considering the distinct soil and experimental conditions of data sets A and B, the result shown in figure 6 and table 6 is promising in terms of consistency of the values of the measured FC and the FC calculated by equation 4 (calibrated for data set A) and M2 (calibrated for data set B). This suggests that our FC data measured in medium-textured samples (n=98) may fit the corresponding data set of Ritchie et al (1999), i.e., A and B may contain the same intrinsic soil variable (FC) in this textural range in spite of the differences in soils and field determination methods.…”

Section: Fc Determination By Ptfsmentioning

confidence: 81%

“…Figure 7 also compares FC R with the measured FC for fine-textured samples (B3). Ritchie et al (1999). This partially explains why the highest measured FC values of subset B3 are underestimated by equation 4.…”

Section: Fc Determination By Ptfsmentioning

confidence: 92%

“…For these soils, equation 4 clearly overestimates FC (Figure 7). The fact that the drainage of clayey profiles is similar to that of coarser soils is a common feature of some tropical soils, which highlights the inadequacy of equation 4 in these cases, as recognized by Ritchie et al (1999). Such hybrid and often-observed behavior of clayed materials of tropical soils was explained by Tomasella et al (2002).…”

Section: Fc Determination By Ptfsmentioning

confidence: 97%

“…In the following discussion, the soil data used by Ritchie et al (1999) to calibrate equation 4 (n=312 samples) we called "A", and our extended data set, "B". The main reasons for possible discrepancies between the measured FC of A and B are: i) the wetting method used with A was not always the same as that of B; ii) there were water losses and gains due to evaporation and rain occurrence in some soil sites of A that were not covered with impermeable material; iii) in A, many soil samples were taken deeper than 1.0 m. Thus, it is probable that the amount of infiltrated water was not sufficient to fully wet (saturation or quasi saturation) the profile up to such depth before monotonic drainage started.…”

Section: Fc Determination By Ptfsmentioning

confidence: 99%

“…To our knowledge, Cassel et al (1983) were the first to apply pedotransfer functions (PTFs) to evaluate field-determined FC. Based on the same data set used by them (312 soil samples from the USA), which was well described by Ratliff et al (1983), Ritchie et al (1999) presented a simple PTF, here called the Ritchie equation, based only on soil bulk density and two granulometric fractions, which gave similar or better results than the model of Cassel et al (1983). Using particle size distribution, bulk density, and the Arya & Paris (1981) model to predict water retention curves, Gerakis & Zalidis (1998) proposed a physical method to estimate fielddetermined FC.…”

Section: Introductionmentioning

confidence: 99%

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Revisiting Field Capacity (FC): variation of definition of FC and its estimation from pedotransfer functions

Filho

Ottoni²,

Oliveira

et al. 2014

Rev. Bras. Ciênc. Solo

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SUMMARYTaking into account the nature of the hydrological processes involved in in situ measurement of Field Capacity (FC), this study proposes a variation of the definition of FC aiming not only at minimizing the inadequacies of its determination, but also at maintaining its original, practical meaning. Analysis of FC data for 22 Brazilian soils and additional FC data from the literature, all measured according to the proposed definition, which is based on a 48-h drainage time after infiltration by shallow ponding, indicates a weak dependency on the amount of infiltrated water, antecedent moisture level, soil morphology, and the level of the groundwater table, but a strong dependency on basic soil properties. The dependence on basic soil properties allowed determination of FC of the 22 soil profiles by pedotransfer functions (PTFs) using the input variables usually adopted in prediction of soil water retention. Among the input variables, soil moisture content θ θ θ θ θ (6 kPa) had the greatest impact. Indeed, a linear PTF based only on it resulted in an FC with a root mean squared residue less than 0.04 m 3 m -3 for most soils individually. Such a PTF proved to be a better FC predictor than the traditional method of using moisture content at an arbitrary suction. Our FC data were compatible with an equivalent and broader USA database found in the literature, mainly for medium-texture soil samples. One reason for differences between FCs of the two data sets of finetextured soils is due to their different drainage times. Thus, a standardized procedure for in situ determination of FC is recommended.Index terms: internal drainage, aeration capacity, soil water retention. Levando em conta a natureza dos processos hidrológicos envolvidos na medição da Capacidade de Campo (CC) in situ, este estudo propõe uma variação da definição de CC a fim de minimizar as impropriedades de sua determinação, mas também de manter seu sentido prático original. A análise de dados de CC para 22 solos brasileiros e de dados adicionais da literatura, todos medidos segundo a definição proposta, que é com base no tempo de drenagem de 48 h após uma infiltração por alagamento raso, indicou fraca dependência na quantidade de água infiltrada, valor de umidade antecedente, morfologia do solo e nível do lençol freático, mas forte dependência nas propriedades básicas do solo. Essa dependência nas propriedades básicas do solo permitiu a determinação da CC dos 22 perfis de solo por funções de pedotransferência (FPTs), utilizando as variáveis de entrada usualmente adotadas na predição de retenção de água no solo. Entre as variáveis de entrada, a umidade θ (6 kPa) foi a que teve maior impacto; de fato, uma FPT linear com base somente nela resultou numa CC com raiz quadrada de resíduo quadrático médio menor que 0,04 m³ m -³, individualmente para todos os solos. Foi evidenciado que tal FPT foi um melhor avaliador da CC do que o método tradicional que utiliza diretamente a umidade a uma sucção arbitrária. Os dados de CC foram compatíveis com uma base de ...

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Section: Fc Determination By Ptfsmentioning

confidence: 81%

Section: Fc Determination By Ptfsmentioning

confidence: 92%

Section: Fc Determination By Ptfsmentioning

confidence: 97%

Section: Fc Determination By Ptfsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Revisiting Field Capacity (FC): variation of definition of FC and its estimation from pedotransfer functions

Filho

Ottoni²,

Oliveira

et al. 2014

Rev. Bras. Ciênc. Solo

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Field Capacity

Skopp

2004

Water Encyclopedia

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Storage of soil water is important to soil flora and fauna, to hydrologic processes, and to a variety of soil physical properties. One element of soil water storage is an upper limit on water that is available for plant use, referred to as “field capacity.” This entry provides a history of the concept, its relation to soil water holding properties, predictive techniques for field capacity, applications, and failures of the field capacity concept. Early researchers of plant water relations quickly realized that in water limited regions, the ultimate crop yield depended not only on the amount of rainfall received but on what portion of that rainfall was usable. Three key factors could reduce the usefulness of rainfall: runoff, drainage below the root zone, and evaporation. The net effect of rainfall, runoff, and drainage results in retention of water in the root zone. Evaporation and transpiration reduce this retained water. This retention was studied by Veihmeyer and Hendrickson. The concepts developed by Veihmeyer and Hendrickson provide a means to evaluate whether a soil retains sufficient water to support a particular crop.

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Overview of Crop Models for Assessment of Crop Production

Ritchie

Alagarswamy

2002

Effects of Climate Change and Variability on Agricultural Production Systems

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Simple Model to Estimate Field-Measured Soilwater Limits

Cited by 98 publications

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Revisiting Field Capacity (FC): variation of definition of FC and its estimation from pedotransfer functions

Revisiting Field Capacity (FC): variation of definition of FC and its estimation from pedotransfer functions

Field Capacity

Overview of Crop Models for Assessment of Crop Production

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