Journal articles: 'Volumetric water content'

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Baker, T. H. W., and L. E. Goodrich. "Measurement of soil water content using the combined time-domain reflectometry – thermal conductivity probe." Canadian Geotechnical Journal 24, no. 1 (February 1, 1987): 160–63. http://dx.doi.org/10.1139/t87-016.

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A two-pronged metal probe measures the thermal conductivity and apparent dielectric constant of soils in the laboratory and in the field. One prong acts as a transient line heat source probe in measuring thermal conductivity. The apparent dielectric constant of the soil is determined by the time-domain reflectometry (TDR) technique, using both prongs as a parallel transmission line. Volumetric water content is determined from the apparent dielectric constant, making use of an empirical relation valid for most soils. For volumetric water contents above about 8%, the apparent dielectric constant shows a strong dependence on water content and relatively small changes can be measured; sensitivity increases with water content. For volumetric water contents less than 8%, a soil-dependent empirical relation between water content and thermal conductivity has been developed that is most sensitive at lower water contents. The combined probe provides a means of monitoring the water content of soils over a wide range of values, in the field and in the laboratory. Key words: soil water content, time-domain reflectometry, thermal conductivity.

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Zhou, Wan-Huan, Ankit Garg, and Akhil Garg. "Study of the volumetric water content based on density, suction and initial water content." Measurement 94 (December 2016): 531–37. http://dx.doi.org/10.1016/j.measurement.2016.08.034.

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Robichaud, P. R., D. S. Gasvoda, R. D. Hungerford, J. Bilskie, L. E. Ashmun, and J. Reardon. "Measuring duff moisture content in the field using a portable meter sensitive to dielectric permittivity." International Journal of Wildland Fire 13, no. 3 (2004): 343. http://dx.doi.org/10.1071/wf03072.

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Duff water content is an important consideration for fire managers when determining favourable timing for prescribed fire ignition. The duff consumption during burning depends largely on the duff water content at the time of ignition. A portable duff moisture meter was developed for real-time water content measurements of non-homogenous material such as forest duff. Using circuitry developed from time and frequency domain reflectometry (TDR and FDR) technologies, this sensor measures a change in frequency that is responsive to the dielectric permittivity of the duff material placed in a sample chamber and compressed. Duff samples from four forest cover types—Douglas fir, larch, lodgepole pine and spruce/alpine fir—were used to calibrate the frequency output to volumetric water content. A second-order polynomial (R2 = 0.97) provides the best fit of the data to volumetric water content. The accuracy of the duff moisture meter is ±1.5% at 30% volumetric water content and ±4% at 60% volumetric water content. The volumetric water content can readily be converted to gravimetric water content, which is used more frequently by fire managers and as an input to predictive models of duff consumption.

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Zhang, Junhui, Feng Li, Ling Zeng, Junhui Peng, Le Ding, and Liang He. "Moisture Migration and Control of New Embankment for Reconstruction and Expansion Project in Southern China." Advances in Civil Engineering 2020 (July 21, 2020): 1–14. http://dx.doi.org/10.1155/2020/7230537.

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In hot and humid regions of southern China, the volumetric moisture content of the embankment after opening to traffic for a period of time reaches a stable state, and it is higher than the design value. When it was widened, the humidity gradient and exchange were formed due to the difference in moisture content between the existing and new embankment. To reveal the moisture migration of the existing and new embankment and control the rise of volumetric moisture content in new embankment, six frequency domain reflectometry sensors were installed in existing and new embankment to monitor the volumetric moisture content. A finite element model for the embankment was established and verified with the measured data. And seven numerical analyses of transient seepage in the new embankment of the cushion, cover, and partition using capillary barrier by sand were simulated. The results show that the volumetric moisture contents of the new embankment in southern China gradually increase and eventually reach an equilibrium state. The increase in water comes from the slope, the foundation, and the existing embankment. Early in the first 1∼2 years, the water mainly comes from the foundation and the existing embankment. After that, as time goes by, the water comes mostly from the slope infiltration and gradually migrates to the foundation and the existing embankment. Finally, the volumetric moisture content and the water storage gradually reach equilibrium. The volumetric moisture content of the new embankment using capillary barrier by sand at the cushion, the cover, and the partition is maintained as the construction volumetric moisture content. This combination is a very effective method to control the humidity stability of the new embankment in southern China.

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Pepin, Steeve, André P. Plamondon, and Jean Stein. "Peat water content measurement using time domain reflectometry." Canadian Journal of Forest Research 22, no. 4 (April 1, 1992): 534–40. http://dx.doi.org/10.1139/x92-070.

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The calibration of time domain reflectometry, previously established for an organic soil of 0.422 Mg•m−3 bulk density, was established for peat blocks with bulk densities ranging from 0.06 to 0.25 Mg•m−3. An empirical relationship between the volumetric water content and the measured apparent dielectric constant was established in the laboratory. This relationship can be used to estimate volumetric water content between 0.21 and 0.95 cm3•cm−3 with a standard deviation of 0.03 cm3•cm−3. The large variations observed during the calibration were mainly attributed to the size and heterogeneousness of peat samples. When water tables in the field were high, standard deviation decreased to 0.02 cm3•cm−3, which agrees very well with other time domain reflectometry experiments.

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Bardanis, Michael. "Volumetric water content measurement probes in earth-dam construction." E3S Web of Conferences 9 (2016): 16004. http://dx.doi.org/10.1051/e3sconf/20160916004.

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Horie, T. "Estimation of the volumetric water content in chrysanthemum tissues." Journal of Radioanalytical and Nuclear Chemistry 264, no. 2 (May 2005): 325–28. http://dx.doi.org/10.1007/s10967-005-0715-8.

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Villoro, Antonio, Borja Latorre, Jaume Tormo, Juan José Jiménez, María Victoria López, José Manuel Nicolau, José Vicente, Ricardo Gracia, and David Moret-Fernández. "A TDR wireless device for volumetric water content sensing." Computers and Electronics in Agriculture 181 (February 2021): 105939. http://dx.doi.org/10.1016/j.compag.2020.105939.

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Jeffries, Matthew D., and Travis W. Gannon. "Soil Organic Matter Content and Volumetric Water Content Affect Indaziflam–Soil Bioavailability." Weed Science 64, no. 4 (December 2016): 757–65. http://dx.doi.org/10.1614/ws-d-16-00039.1.

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Indaziflam is a cellulose biosynthesis-inhibiting herbicide for annual weed control in various agricultural systems. Sporadic cases of unacceptable injury to desirable plants have been reported after indaziflam application, which may have been due to conditions favoring increased indaziflam–soil bioavailability. Research was conducted from 2013 to 2015 on a sandy soil to elucidate the effects of soil organic matter content (SOMC) and soil volumetric water content (SVWC) on indaziflam–soil bioavailability. Indaziflam was applied (50 or 100 g ha–1) at fall only, fall plus spring, and spring only timings to plots in a factorial arrangement of SOMC, pre–indaziflam application (PrIA) SVWC, and post–indaziflam application (PoIA) SVWC. After application, field soil cores were collected for a subsequent greenhouse bioassay experiment, where foliage mass reduction of perennial ryegrass seeded from 0 to 15 cm soil depth was used as an indicator of indaziflam–soil bioavailability throughout the profile. Significant edaphic effects were observed at 0 to 2.5, 2.5 to 5, and 5 to 7.5 cm depths, with increased bioavailability at low compared with high SOMC. Pre–indaziflam application SVWC did not affect bioavailability, whereas PoIA high SVWC increased indaziflam–soil bioavailability at 2.5 to 7.5 cm depth compared with PoIA low SVWC. Low SOMC–PoIA high SVWC decreased perennial ryegrass foliage mass 40 and 37% at 5 to 7.5 cm depth from cores collected 10 and 14 wk after treatment, respectively, whereas reductions from all other SOMC–PoIA SVWC combinations were < 12% and did not vary from each other. Pearson's correlation coefficients showed a moderate, positive relationship between perennial ryegrass mass reductions at 0 to 2.5, 2.5 to 5, 0 to 5, and 0 to 10 cm depths and hybrid bermudagrass cover reduction, which suggests conditions favoring increased indaziflam–soil bioavailability can adversely affect plant growth. Data from this research will aid land managers to use indaziflam effectively without adversely affecting growth of desirable species.

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Martin, Chris A., and Dewayne L. Ingram. "RELATIONSHIPS OF IRRIGATION AND MEDIUM COMPOSITION TO TEMPERATURE DYNAMICS IN CONTAINER MEDIA." HortScience 25, no. 8 (August 1990): 849e—849. http://dx.doi.org/10.21273/hortsci.25.8.849e.

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Thermal properties of pine bark: sand container media as a function of volumetric water content and effectiveness of irrigation as a tool for modulating high temperatures in container media were studied. Volumetric water and sand content interacted to affect container medium thermal diffusivity. Adding sand to a pine bark container medium decreased thermal diffusivity if volumetric water content was less than 10 percent and increased thermal diffusivity if volumetric water content was between 10 and 70 percent. Thermal diffusivity was greatest for a 3 pine bark : 2 sand container medium if volumetric water content was between 30 and 70 percent. Irrigation was used to decrease temperatures in 10-liter container media. Irrigation water at 26°C was more effective if 1) volumes equaled or exceeded 3000 ml, 2) applications were made during mid-day, and 3) sand was present in the container medium compared to pine bark alone. However, due to the volume of water required to lower container media temperatures, nursery operators should first consider reducing incoming irradiance via overhead shade or container spacing.

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Monje, O., G. D. Goins, H. G. Levine, and G. W. Stutte. "295 Controlling Crop Growth Media Moisture with Sensors." HortScience 35, no. 3 (June 2000): 442D—442. http://dx.doi.org/10.21273/hortsci.35.3.442d.

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Tight control of growth media moisture content is needed when plant growth systems employ shallow root zones or for cultivating fast-growing plants (i.e., crops). Poor control of moisture can affect both growth rate and plant quality by either excessive watering (waterlogging) or drought events. We evaluated the performance of two types of moisture sensors: tensiometers and heat-pulse moisture sensors. The output from each sensor type was evaluated as a function of volumetric moisture content in 1 to 2 mm Turface. The tensiometers were more sensitive between 30% and 60% volumetric moisture content, and their output was nonlinear because they measure water potential directly. In contrast, both the sensitivity and the output of the heat-pulse moisture sensors, as a function of volumetric moisture content, were linear. The heat-pulse moisture sensors were used to control moisture content in a shallow root zone, whereby water was added or removed from the media through a porous tube using peristaltic pumps. Moisture content in the media could be maintained within ±2% of setpoint for moisture contents ranging from 20% to 100% volumetric moisture content. The heat-pulse sensors were better suited for controlling media moisture because of their linear output and because of their constant sensitivity as a function of volumetric moisture content.

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Dias, Ana Sofia, Abhijith Kamath, Marianna Pirone, and Gianfranco Urciuoli. "Water retention and shrinkage curves of weathered pyroclastic soil." E3S Web of Conferences 195 (2020): 03003. http://dx.doi.org/10.1051/e3sconf/202019503003.

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The modelling of the triggering mechanism of rainfall-induced landslides in slopes covered by pyroclastic soil (as the area surrounding Mount Vesuvius in Campania, Italy) requires the hydraulic characterization of soil in unsaturated conditions in order to analyse the slope response to rainfalls. In previous studies carried out on Campanian pyroclastic soils, the volumetric soil changes due to suction changes have been disregarded, being them negligible in soils characterized by low plasticity and low clay contents. However, a more accurate determination of the water retention curve (WRC) in terms of volumetric water content requires a correct estimation of the total soil volume, which is affected by the soil stress-state. The proper approach would require the estimation of both WRC in terms of gravimetric water content and the shrinkage curve (SC). In the present study, a relation between void ratio and suction was determined for a pyroclastic soil sampled at Mount Faito in Southern Italy. Therefore, a correction of the volumetric water content was carried out resulting in updated water retention curves. Here, the matric suction was the only factor affecting the stress-state of the soil.

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Sun, Z. J., G. D. Young, R. A. McFarlane, and B. M. Chambers. "The effect of soil electrical conductivity on moisture determination using time-domain reflectometry in sandy soil." Canadian Journal of Soil Science 80, no. 1 (February 1, 2000): 13–22. http://dx.doi.org/10.4141/s98-089.

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A series of laboratory experiments was conducted, in order to systematically explore the effect of soil electrical conductivity on soil moisture determination using time domain reflectometry (TDR). A Moisture Point MP-917 soil moisture instrument (E.S.I. Environmental Sensors Inc., Victoria, BC, Canada) was used to measure propagation time (time delay) of a step function along a probe imbedded in fine sand with different moisture and salinity. The volumetric soil water content was independently determined using a balance. With the help of the diode-switching technique, MP-917 could detect the reflection from the end of the probe as the electrical conductivity of saturated soil extract (ECe) increased to 15.29 dS m−1. However, the relationship between volumetric soil water content and propagation time expressed as T/Tair (the ratio of propagation time in soil to that in air over the same distance) deviated from a linear relationship as the conductivity exceeded 3.72 dS m−1. At the same water content, the time delay in a saline soil was longer than that in a non-saline soil. This leads to an over-estimation of volumetric soil water content when the linear calibration was applied. A logarithmic relationship between volumetric soil water content and T/Tair has been developed and this relation includes soil electrical conductivity as a parameter. With this new calibration, it is possible to precisely determine the volumetric water content of highly saline soil using TDR. Key words: Time domain reflectometry, time delay, bulk electrical conductivity (σ), volumetric soil water content (θ), relative permittivity or dielectric constant (εr), propagation velocity Vp

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Chen, Cunli, Dengfei Zhang, and Jie Zhang. "Influence of stress and water content on air permeability of intact loess." Canadian Geotechnical Journal 54, no. 9 (September 2017): 1221–30. http://dx.doi.org/10.1139/cgj-2016-0186.

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Air permeability is one of the key parameters in performing consolidation analysis of unsaturated soil. Few data are available regarding the air permeability for intact loess under different applied stresses. The work reported in this paper evaluated the air permeability at isotropic stress using data obtained from laboratory investigations for intact loess. Air permeability tests were performed on specimens of intact loess at various water contents and isotropic stresses. Stress remarkably affected air permeability as a function of both liquid saturation and volumetric air content. There were all unique relationships not only between relative air permeability and liquid saturation as well as relative volumetric air content, but also between air permeability and modified air saturation for different stresses. The relative air permeability against liquid saturation could be well described by the Parker–van Genuchten–Mulaem (P-vG-M) model in terms of total liquid saturation. The relationship between relative air permeability and relative volumetric air content could be more conveniently expressed by the reference point power law (RPL) model, using the reference point values at natural water content rather than that at air-dried water content. Compared with the other two models, the proposed modified air saturation power law (MAPL) model was more appropriate to predict the air permeability.

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Steinberg, Susan L., Gerard J. Kluitenberg, and Soheni Tanzeema. "Roots Affect the Accuracy of Dual-probe Heat-pulse Method for Measuring Water Content in Plant Growth Media." HortScience 41, no. 4 (July 2006): 970E—971. http://dx.doi.org/10.21273/hortsci.41.4.970e.

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Little attention has been paid to how the presence of roots influences water content measurements obtained with water content sensors. This issue is especially important if sensors are deployed in densely rooted soil or growth media. This work addresses the impact of roots on water content measurements obtained with dual-probe heat-pulse (DPHP) sensors. In the DPHP method, the maximum temperature rise in response to heating (Tmax) is used to calculate volumetric heat capacity, which in turn is used to calculate volumetric water content. The accuracy of DPHP sensors was evaluated in unrooted and rooted 0.25–1 mm baked ceramic aggregate. For both restricted and unrestricted volumes of aggregate the presence of roots caused DPHP sensors to consistently overestimate water content by 0.05–0.09 cm3·cm-3. Measured values of Tmax were lower in the presence of roots, which resulted in overestimation of volumetric heat capacity that was attributed to the high specific heat of water contained in roots in addition to that contained within the aggregate. Differences in water content and aggregate heating between unrooted and rooted aggregate equilibrated to the same matric potential were less distinct in unrestricted volumes, where the decrease in bulk density has the offsetting effect of lowering the heat capacity. Error in water content caused by the presence of roots and changes in bulk density was estimated by developing a theoretical mixing model for volumetric heat capacity that accounted for the heat capacity of all constituents, including aggregate, water, root water, and root tissue. Predicted errors in volumetric water content due to changes in bulk density or changes in heat capacity due to roots agreed well with direct measurement.

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Al Majou, Hassan, Ary Bruand, and Odile Duval. "The use of in situ volumetric water content at field capacity to improve the prediction of soil water retention properties." Canadian Journal of Soil Science 88, no. 4 (August 1, 2008): 533–41. http://dx.doi.org/10.4141/cjss07065.

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Most pedotransfer functions (PTF) developed over the past three decades to generate water retention characteristics use soil texture, bulk density and organic carbon content as predictors. Despite the high number of PTFs published, most being class- or continuous-PTFs, the accuracy of prediction remains limited. In this study, we compared the performance of different class- and continuous-PTFs developed with a regional database. Results showed that the use of in situ volumetric water content at field capacity as a predictor led to much better estimation of water retention properties compared with using predictors derived from the texture, or the organic carbon content and bulk density. This was true regardless of the complexity of the PTFs developed. Results also showed that the best prediction quality was achieved by using the in situ volumetric water content at field capacity after stratification by texture. Comparison of in situ volumetric water content at field capacity, with the water retained at different matric potentials as measured in the laboratory, showed field capacity to approximate 100 hPa, whatever the soil texture. Finally, the lack accuracy of PTFs that do not use the in situ volumetric water content at field capacity as predictor did not appear due to the test soils being unrepresentative of the soils used to develop the PTFs, but were instead related to poor correlations between the predictors used and the water retention properties. Key words: Pedotransfer functions, root mean square error, mean error of prediction, standard deviation of prediction, texture, bulk density, organic carbon content

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Hong, Won-Taek, Jung-Doung Yu, Sang Yeob Kim, and Jong-Sub Lee. "Dynamic Cone Penetrometer Incorporated with Time Domain Reflectometry (TDR) Sensors for the Evaluation of Water Contents in Sandy Soils." Sensors 19, no. 18 (September 5, 2019): 3841. http://dx.doi.org/10.3390/s19183841.

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Ground moisture content and strength properties are the most important factors for a proper assessment of ground stability. This study developed a dynamic cone penetrometer incorporated with time domain reflectometry (TDR) sensors (TDCP). The TDCP is composed of an anvil, a driving rod, and a TDCP probe. Three wave guides and a K-type thermocouple are installed on the TDCP probe. For utilization of TDCP, relationships between relative permittivities measured by TDCP and those measured by standard TDR probe, temperature, and volumetric water content of the soils were investigated. In addition, the relationship between penetration indices by TDCP (TPI) and by standard dynamic cone penetrometer was established. In the field application test, relative permittivity, ground temperature, and TPI were measured along the depth. Moreover, gravimetric water contents were also measured for comparison. The experimental results showed that volumetric water contents compensated by ground temperature showed good agreement with the volumetric water contents estimated from the gravimetric water contents of the soil samples and TPI. This study suggests that the TDCP may be effectively used for the evaluation moisture contents and for the strength characterization of the subsurface.

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Guenette, Kris, and Guillermo Hernandez-Ramirez. "Can Faba Bean Physiological Responses Stem from Contrasting Traffic Management Regimes?" Agronomy 8, no. 10 (September 21, 2018): 200. http://dx.doi.org/10.3390/agronomy8100200.

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Our study examined how faba beans (Vicia faba L.) grown in soil conditions that simulate common traffic management regimes and water availabilities displayed alterations to their physiological state. Physiological changes were tracked through plant and sensor-based measurements, such as evapotranspiration, water use efficiency, aboveground biomass, stomatal conductance, and normalized difference vegetation index. A greenhouse experiment comprised of faba beans were sown into pots of two different soil types that were separated by treatments of dry bulk density and volumetric water content. The compaction treatment with a bulk density of 1.2 g cm−3 coupled with a volumetric water content of 41% displayed more favorable changes to the physiological state of the faba beans than the contrasting treatment of 1.4 g cm−3 bulk density at 33% volumetric water content. Handheld sensor-based measurements, such as the normalized difference vegetation index, exhibited a strong correlation with faba bean biomass production. Furthermore, the stomatal conductance was able to reveal plant water stress and capture evapotranspiration responses. Conclusive observations showed that increasing soil compaction restricted plant productivity. However, the presence of high water content was shown to offset the negative effects of heavily applied compaction while relatively lower water contents exacerbated differences in plant responses across compaction treatments.

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Dlamini, Phesheya, and Vincent Chaplot. "On the interpolation of volumetric water content in research catchments." Physics and Chemistry of the Earth, Parts A/B/C 50-52 (2012): 165–74. http://dx.doi.org/10.1016/j.pce.2012.09.008.

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WYSEURE, G. C. L., M. A. MOJID, and M. A. MALIK. "Measurement of volumetric water content by TDR in saline soils." European Journal of Soil Science 48, no. 2 (June 1997): 347–54. http://dx.doi.org/10.1111/j.1365-2389.1997.tb00555.x.

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Kaplanvural, İ., E. Pekşen, and K. Özkap. "Volumetric water content estimation of C-30 concrete using GPR." Construction and Building Materials 166 (March 2018): 141–46. http://dx.doi.org/10.1016/j.conbuildmat.2018.01.132.

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Mukhlisin, Muhammad, and Almushfi Saputra. "Performance Evaluation of Volumetric Water Content and Relative Permittivity Models." Scientific World Journal 2013 (2013): 1–7. http://dx.doi.org/10.1155/2013/421762.

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In recent years many models have been proposed for measuring soil water content (θ) based on the permittivity (ε) value. Permittivity is one of the properties used to determineθin measurements using the electromagnetic method. This method is widely used due to quite substantial differences in values ofεfor air, soil, and water, as it allows theθvalue to be measured accurately. The performance of six proposed models with one parameter (i.e., permittivity) and five proposed models with two or more parameters (i.e., permittivity, porosity, and dry bulk density of soil) is discussed and evaluated. Secondary data obtained from previous studies are used for comparison to calibrate and evaluate the models. The results show that the models with one parameter proposed by Roth et al. (1992) and Topp et al. (1980) have the greatestR2data errors, while for the model with two parameters, the model proposed by Malicki et al. (1996) agrees very well with the data compared with other models.

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Brant, V., J. Pivec, V. Venclová, J. Soukup, and J. Holec J. "The influence of different soil vegetation covers onto the volumetric water content in upper soil layers." Plant, Soil and Environment 52, No. 6 (November 17, 2011): 275–81. http://dx.doi.org/10.17221/3441-pse.

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The influence of different vegetation cover of the set aside land on the volumetric water content VWC (%) and its variations during the day in upper soil layers (5 and 15 cm) using the TDR method was observed in 15 min intervals from May to August in 2002 and 2003. A spontaneous fallow was established in autumn 2001 and plots with artificial revegetation sowed with grass-legume mixture of Dactylis polygama Horv. and Trifolium repens L. in spring 2002. The experimental plots were mulched twice during the vegetation period. VWC (%) was registered in the same time also on bare ground. The control plot was sown with crops (Brassica napus L. – 2002 and Triticum aestivum L. – 2003) and regular tillage using ploughing was applied. The highest values of VWC (%) during observed period were recorded on bare ground. The values of VWC (%) on set aside soil with vegetation cover and on control plot were lower. The lowest values of VWC (%) were recorded in 5 cm depth on plot sowed with grass-legume mixture of D. polygama and T. repens. Values of VWC (%) on spontaneous fallow were lower in depth of 15 cm compared to the 5 cm depth. The highest variation of daily VWC (%) run was recorded on bare ground.

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Harnas, F. R., H. Rahardjo, E. C. Leong, and J. Y. Wang. "Experimental study on dual capillary barrier using recycled asphalt pavement materials." Canadian Geotechnical Journal 51, no. 10 (October 2014): 1165–77. http://dx.doi.org/10.1139/cgj-2013-0432.

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The performance of a capillary barrier cover as a cover system is affected by the ability of the capillary barrier to store water. To increase the water storage of a capillary barrier cover, the dual capillary barrier (DCB) concept is proposed. The objective of this paper is to investigate the water storage of the proposed DCB as compared to the storage of a traditional single capillary barrier (SCB). The investigation is conducted using two one-dimensional infiltration column tests under different rainfall conditions. The results show that a DCB stores more water as compared to SCB. The results show that the fine-grained layers of a DCB have higher volumetric water contents during drainage as compared to that of the fine-grained layer of an SCB. The higher volumetric water content is caused by the fact that the thickness of the layers in a DCB corresponds to a pore-water pressure head range where the material has the highest volumetric water content. In addition, a slower drainage rate is resulted from additional layering in a DCB.

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Burnett, Stephanie E., and Marc W. van Iersel. "Morphology and Irrigation Efficiency of Gaura lindheimeri Grown with Capacitance Sensor-controlled Irrigation." HortScience 43, no. 5 (August 2008): 1555–60. http://dx.doi.org/10.21273/hortsci.43.5.1555.

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Gaura lindheimeri Engelm. & Gray ‘Siskiyou Pink’ (gaura) and Phlox paniculata L. ‘David’ (garden phlox) were grown for 5 weeks in substrates irrigated at volumetric water contents (Θ) of 0.10, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.45 m3·m−3 using a capacitance sensor-controlled irrigation system. Volumetric water contents of the substrate measured by the capacitance sensors controlling irrigation were correlated with measurements with a separate handheld meter (r 2 = 0.83) and with volumetric water content set points throughout the study (r 2 > 0.98). Only 3.8 (at an irrigation set point of 0.10 m3·m−3) to 53 L (0.45 m3·m−3) of water was used to irrigate gaura and phlox and 0 to 7.74 L of this water leached out of the substrates. Significant leaching occurred only at Θ set points of 0.40, or 0.45 m3·m−3. Gaura had shorter and fewer branches and reduced dry weight when grown at lower volumetric water contents, but plants irrigated at set points above 0.25 m3·m−3 were large enough to be marketable. Gaura may be grown with capacitance sensor-automated irrigation using water efficiently and minimizing or eliminating leachate and thus nonpoint source pollution.

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Currey, Christopher J., Nicholas J. Flax, Alexander G. Litvin, and Vincent C. Metz. "Substrate Volumetric Water Content Controls Growth and Development of Containerized Culinary Herbs." Agronomy 9, no. 11 (October 23, 2019): 667. http://dx.doi.org/10.3390/agronomy9110667.

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There are no chemical plant growth retardants that may be used on containerized culinary herbs intended for consumption. Our objective was to quantify the effect of substrate moisture content on the growth of four commonly produced culinary annual herbs grown in containers in the greenhouse. Seedlings of basil (Ocimum basilicum L.), dill (Anethum graveolens L.), parsley (Petroselinum crispum (Mill.) Fuss), and sage (Salvia officinalis L.) were transplanted into 11.4 cm diameter containers filled with commercial soilless substrate comprising (by vol.) 75% sphagnum peat moss and 25% coarse perlite and amended with 3.0 kg·m−3 of controlled-release fertilizer. After the containers were thoroughly irrigated to container capacity, plants were placed into a sensor-controlled irrigation system, which maintained substrate volumetric water content (VWC) at 0.15, 0.28, 0.30, 0.38, or 0.45 m3·m−3. Chlorophyll fluorescence, photosynthesis, stomatal conductance, and transpiration were measured 27 d after initiating treatments, and the results showed that chlorophyll fluorescence of parsley and photosynthesis of basil increased as substrate VWC increased from 0.15 to 0.45 m3·m−3; the remaining parameters for basil, parsley, and sage were unaffected. Additionally, height, width, leaf area, and shoot dry mass of basil, dill, parsley, and sage increased as substrate volumetric water content increased from 0.15 to 0.45 m3·m−3. Our results show that growth of basil, dill, parsley, and sage can be promoted or inhibited by providing or withholding water, respectively, with no signs of stress or visual damage resulting from reduced substrate volumetric water content. Therefore, restricting irrigation and substrate volumetric water content is an effective nonchemical growth control method for containerized culinary herbs grown in peat-based substrate.

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Tang, Yaming, Heping Shu, Qiang Xue, Jiayun Wang, Wei Feng, Hongna Ma, Yan’e Li, Jin Luo, and Hamid Reza Pourghasemi. "Field Monitoring-Based and Theoretical Analysis of Baota Mountain Landslide Stability." Advances in Civil Engineering 2021 (March 23, 2021): 1–16. http://dx.doi.org/10.1155/2021/6699917.

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Landslide is one of the most widely distributed surface morphological landscapes, and it can cause a series of major economic and human losses. Field monitoring and limit equilibrium methods were applied to investigate Baota Mountain landslide stability, and soil volumetric water content, different scales of rainfall data, and landslide displacements were monitored using various equipment. The theoretical factor of safety was also calculated for the landslide. Finally, the theoretical results were validated by monitoring data in the field. The results demonstrate that soil volumetric water content experienced the greatest change with time at a depth of 0.2 m and then 1 m; however, the change in soil volumetric water content was relatively small with time at a soil depth ranging from 2.0 m to 4.0 m. Soil volumetric water content also did not change with time at a soil depth of 5.0 m and below. In addition, the retardation effect was found in different depths of volumetric water content for continuous rainfall. The safety factors were 2.713 and 1.133 for landslide No. 1 and landslide No. 2, respectively. These results indicate that landslide No. 1 is relatively stable, but there is a probability of the occurrence of movement in landslide No. 2. The monitoring displacement data indicate that landslide No.1 was in a relatively stable state between 2008 and 2013, and this result was in accordance with the value of theoretical calculation. This study provided relevant parameters for numerical simulation of landslides in loess areas.

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28

Almeida, Karla Silva Santos Alvares de, Luciano Da Silva Souza, Vital Pedro Da Silva Paz, Maurício Antônio Coelho Filho, and Eduardo Holzapfel Hoces. "Models for moisture estimation in different horizons of yellow argisol using TDR." Semina: Ciências Agrárias 38, no. 4 (August 4, 2017): 1727. http://dx.doi.org/10.5433/1679-0359.2017v38n4p1727.

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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 (?) 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.

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Bullock, P. R., X. Li, and L. Leonardi. "Near-infrared spectroscopy for soil water determination in small soil volumes." Canadian Journal of Soil Science 84, no. 3 (August 1, 2004): 333–38. http://dx.doi.org/10.4141/s03-090.

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Critical soil water levels for soil microscale processes are difficult to determine because of variability in large soil volumes and lack of techniques for logging soil water contents in small soil volumes. This study tested nearinfrared (NIR) spectroscopy for soil water content determination. Five soil horizons with a range in soil texture, soil organic carbon, carbonates, pH and horizon depth, were tested at air-dry, field capacity and 0.1 MPa tension water content. Volumetric soil water content, determined using the standard method of oven-drying and soil bulk density, was compared to NIR absorbance in various combinations and wavelengths. The NIR spectra obtained with the probe in direct contact with the soil gave better results than when the probe was separated from the soil with a glass slide. The most reliable validation results were obtained using a multivariate partial least squares regression of the full spectrum with an r2 of 0.95 and RMSE of prediction of 6.4%. Smoothing and derivatives of the spectra did not improve the validation results. The relationships for absorbance at single wavelength segments, ratios, differences and area under the curve around the 1940 nm peak were good (r2 values near 0.85 ) but poorer than the results using the full spectra. The high correlation coefficients obtained with the wide variety of soils utilized in this study suggest that NIR absorbance is a practical method for determining volumetric soil water content for small soil volumes. Key words: Near-infrared spectroscopy, soil water, Near-infrared absorbance

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Casanova, Pedro, Paulo C. Corrêa, and Kattia Solís. "Volumetric shrinkage and shape of Conilon coffee fruit (Coffea Canephora)." Journal of Agricultural Studies 2, no. 1 (February 7, 2014): 73. http://dx.doi.org/10.5296/jas.v2i1.4617.

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The effect of varying the water content was evaluated in shrinkage, dimensional characteristics and shape of the fruits of coffee during drying. Fruits were used Conilon coffee (Coffea canephora), clone 83 of clonal variety EMCAPA 8141. The fruit was hand-picked and selected only the two stages, cherry and unripe. Different batches of coffee were dried in an oven with forced ventilation with air temperature of approximately 60 ± 3 °C until different levels of water content. Fruit size was determined by varying the volume and shape was examined by sphericity and roundness. The shrinkage of the fruits was determined by the ratio between the volume at each water content and initial volume. It was determined that the projected area, surface area and volume increase with increasing water content for conilon coffee fruit. The shape of the conilon coffee fruits was influenced during the drying process, promoting the decrease of sphericity and roundness values from the reduction of water content. The shrinkage showed a nonlinear behavior with decreasing reducing the water content of the mass of Conilon coffee fruit. The polynomial model represented satisfactorily phenomenon of unit volumetric shrinkage and mass of coffee fruits depending on the water content.

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Zou, C., R. Sands, G. Buchan, and I. Hudson. "Least limiting water range: a potential indicator of physical quality of forest soils." Soil Research 38, no. 5 (2000): 947. http://dx.doi.org/10.1071/sr99108.

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The interactions of the 4 basic soil physical properties—volumetric water content, matric potential, soil strength, and air-filled porosity—were investigated over a range of contrasting textures and for 3 compaction levels of 4 forest soils in New Zealand, using linear and non-linear regression methods. Relationships among these properties depended on texture and bulk density. Soil compaction increased volumetric water contents at field capacity, at wilting point, and at the water contents associated with restraining soil strength values, but decreased the water content when air-filled porosity was limiting. The integrated effect of matric potential, air-filled porosity, and soil strength on plant growth was described by the single parameter, least limiting water range (LLWR). LLWR defines a range in soil water content within which plant growth is least likely to be limited by the availability of water and air in soil and the soil strength. Soil compaction narrowed or decreased LLWR in most cases. In coarse sandy soil, initial compaction increased LLWR, but further compaction decreased LLWR. LLWR is sensitive to variations in forest management practices and is a potential indicator of soil physical condition for sustainable forest management.

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Paraskevas, C., P. Georgiou, A. Ilias, A. Panoras, and C. Babajimopoulos. "Calibration equations for two capacitance water content probes." International Agrophysics 26, no. 3 (July 1, 2012): 285–93. http://dx.doi.org/10.2478/v10247-012-0041-7.

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Calibration equations for two capacitance water content probesThis paper presents the calibration equations of two capacitance probes for monitoring the soil water content in a lysimeter field. Capacitance probes provide readings at desired depths and time intervals. The calibration equations are derived by regression analysis between measurements of scaled frequency and volumetric soil water content. The calibration equations are compared with the manufacturer default equations to estimate the irrigation water depth. The accuracy of capacitance probes in monitoring soil water content increased by using the site-specific calibration equations rather than the manufacturer default equation.

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Aringhieri, R., and M. Giachetti. "ASSESSING SOIL VOLUMETRIC WATER CONTENT AND SALINITY BY TIME DOMAIN REFLECTOMETRY." Acta Horticulturae, no. 573 (March 2002): 29–34. http://dx.doi.org/10.17660/actahortic.2002.573.2.

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34

Overduin, Pier P., Kenji Yoshikawa, Douglas L. Kane, and Jennifer W. Harden. "Comparing electronic probes for volumetric water content of low‐density feathermoss." Sensor Review 25, no. 3 (September 2005): 215–21. http://dx.doi.org/10.1108/02602280510606507.

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35

Klysz, G., and J. P. Balayssac. "Determination of volumetric water content of concrete using ground-penetrating radar." Cement and Concrete Research 37, no. 8 (August 2007): 1164–71. http://dx.doi.org/10.1016/j.cemconres.2007.04.010.

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Sun, Wendell Q., Yongheng Liang, Shangzhi Huang, and Jiarui Fu. "Biopolymer volume change and water clustering function of primed Vigna radiata seeds." Seed Science Research 13, no. 4 (December 2003): 287–302. http://dx.doi.org/10.1079/ssr2003146.

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Osmotic priming reduces the longevity of Vigna radiata (mung bean) seeds during subsequent dry storage. The present study has investigated the relationship between volumetric changes, modified water sorption properties and the decrease in seed longevity after priming. Volumetric analysis of control embryos revealed two major dehydration-related volumetric contractions in the biopolymer matrix, reflecting structural reorganization in biopolymer matrix during drying. These contractions occurred at hydration from 0.29 to 0.23 g g–1 dw and from 0.18 to 0.11 g g–1 dw, respectively. Volumetric contractions were reduced significantly after priming and also occurred at higher water contents (i.e. 0.48–0.32 g g–1 dw and 0.21–0.11 g g–1 dw). Consequently, at the same water content, primed seed embryos had higher specific biopolymer volume and lower specific density than control embryos. Water sorption study showed that priming did not change the monolayer hydration value, but altered the properties of multilayer water sorption in seed axes. The analysis of water clustering function suggested that priming enhanced the water–water association in seed axes, but not in cotyledon tissues. Solid-state 1H-NMR (nuclear magnetic resonance) investigation confirmed that priming did not cause a significant change of water dynamic properties in cotyledon tissues at water contents below 0.20 g g–1 dw. The relevance of volumetric modifications of the biopolymer matrix and changes in water clustering function to the reduced seed longevity after priming is discussed. It is proposed that priming-induced increases in surface reactivity may enhance deteriorative chemical reactions in re-dried seed tissues.

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37

Tsai, Yi-Zhih, Kan-Sheng Hsu, Hung-Yu Wu, Shu-I. Lin, Hwa-Lung Yu, Kuo-Tsang Huang, Ming-Che Hu, and Shao-Yiu Hsu. "Application of Random Forest and ICON Models Combined with Weather Forecasts to Predict Soil Temperature and Water Content in a Greenhouse." Water 12, no. 4 (April 20, 2020): 1176. http://dx.doi.org/10.3390/w12041176.

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Climate change might potentially cause extreme weather events to become more frequent and intense. It could also enhance water scarcity and reduce food security. More efficient water management techniques are thus required to ensure a stable food supply and quality. Maintaining proper soil water content and soil temperature is necessary for efficient water management in agricultural practices. The usage of water and fertilizers can be significantly improved with a precise water content prediction tool. In this study, we proposed a new framework that combines weather forecast data, numerical models, and machine learning methods to simulate and predict the soil temperature and volumetric water content in a greenhouse. To test the framework, we performed greenhouse experiments with cherry tomatoes. The numerical models and machine learning methods we selected were Newton’s law of cooling, HYDRUS-1D, the random forest model, and the ICON (inferring connections of networks) model. The measured air temperature, soil temperature, and volumetric water content during the cultivation period were used for model calibration and validation. We compared the performances of the models for soil temperature and volumetric water content predictions. The results showed that the random forest model performed a more accurate prediction than other methods under the limited information provided from greenhouse experiments. This approach provides a framework that can potentially learn best water management practices from experienced farmers and provide intelligent information for smart greenhouse management.

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38

BEKE, G. J., and M. I. MacCORMICK. "PREDICTING VOLUMETRIC WATER RETENTIONS FOR SUBSOIL MATERIALS FROM COLCHESTER COUNTY, NOVA SCOTIA." Canadian Journal of Soil Science 65, no. 1 (February 1, 1985): 233–36. http://dx.doi.org/10.4141/cjss85-026.

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Relationships between soil water retention and soil properties were developed for subsoil materials from Colchester County, Nova Scotia. The significant variables in the regression equation for soil water content at a suction of 33 kPa were the sand content and the product of silt content and bulk density of the soil. The variables for water retention at 1500 kPa suction were the clay content and the product of organic matter content and bulk density. The multiple correlation coefficients were 0.87 and 0.92 for suctions of 33 and 1500 kPa, respectively. The developed equations were comparable to ones derived elsewhere. Key words: Water retention, texture, organic matter, bulk density

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39

Foley, J. L., and E. Harris. "Field calibration of ThetaProbe (ML2x) and ECHO probe (EC-20) soil water sensors in a Black Vertosol." Soil Research 45, no. 3 (2007): 233. http://dx.doi.org/10.1071/sr06156.

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Past studies have shown that soil-specific calibrations are required to attain a higher level of accuracy when measuring soil water content with ThetaProbe and ECHO probe soil water sensors, particularly in swelling clay soils. Both probes were assessed for their capacity to accurately monitor soil water in a deep drainage study on a Black Vertosol. Probes were trialled in situ and calibrated against hand-sampled volumetric measurements. The generic calibrations given by the manufacturers resulted in significant errors in water content estimates for both probes. Using the generic calibration, ECHO probes under-estimated water content by 0.10–0.2 m3/m3, whereas ThetaProbes under-estimated by 0.04 m3/m3 at the wet end and over-estimated by 0.08 m3/m3 at the dry end. The soil-specific calibrations significantly improved the accuracy of both probes. ThetaProbes were chosen for the drainage study. The calibration allowed for accuracy across the full wet–dry range to within 0.001–0.004 m3/m3 of volumetric measurements. ECHO probes were less accurate at the wet end, but still determined soil water content to within 0.02–0.05 m3/m3 of volumetric measurements.

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40

Engelhart, G. J., L. Hildebrandt, E. Kostenidou, N. Mihalopoulos, N. M. Donahue, and S. N. Pandis. "Water content of aged aerosol." Atmospheric Chemistry and Physics Discussions 10, no. 9 (September 14, 2010): 21653–81. http://dx.doi.org/10.5194/acpd-10-21653-2010.

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Abstract. The composition and physical properties of aged atmospheric aerosol were characterized at a remote sampling site on the northern coast of Crete, Greece induring the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-2008). A reduced Dry-Ambient Aerosol Size Spectrometer (DAASS) was deployed to measure the aerosol water content and volumetric growth factor of fine particulate matter. The particles remained wet even at relative humidity (RH) as low as 20%. The aerosol was acidic during most of the measurement period, which likely contributed to the water uptake at low RH. The water content observations were compared to the thermodynamic model E-AIM, neglecting any contribution of the organics to aerosol water content. There was good agreement between the water measurements and the model predictions. Adding the small amount of water associated with the organic aerosol based on monoterpene water absorption did not change the quality of the agreement. These results strongly suggest that the water uptake by aged organic aerosol is relatively small (a few percent of the total water for the conditions of FAME-08) and generally consistent with what has been observed in laboratory experiments. The Q-AMS water concentration was well correlated with the DAASS measurements and in good agreement with the predicted values for the RH of the Q-AMS inlet. This suggests, that at least for the conditions of the study, the Q-AMS can provide valuable information about the aerosol water concentrations if the sample is not dried.

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41

Niu, Lisi, Aijun Zhang, Jiamin Zhao, Wenyuan Ren, Yuguo Wang, and Zhichao Liang. "Study on Soil-Water Characteristics of Expansive Soil under the Dry-Wet Cycle and Freeze-Thaw Cycle considering Volumetric Strain." Advances in Civil Engineering 2021 (January 29, 2021): 1–13. http://dx.doi.org/10.1155/2021/6622370.

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This paper targets the expansive soils in Heilongjiang and Ankang to explore the influence of initial dry density, dry-wet cycle, and freeze-thaw cycle on the soil-water characteristics. The centrifuge method was used to obtain the soil-water characteristic curves (SWCCs) with different conditions. The volumetric strain of SWCC was modified based on the shrinkage test, and the corresponding fitting equations considering different factors were established. The results show that the volumetric water content is modified to consider the volume shrinkage effect of expansive soil, and the modification is more obvious in the high matric suction range. The smaller the initial dry density is, the worse the water-holding capacity of the sample is, and the smaller the air intake value is. The greater the time of the dry-wet cycle is, the greater the saturated volumetric water content of the sample is, and the corresponding water-holding capacity is significantly reduced. When the dry-wet cycle increases to a certain extent, the structure becomes stable. With the increase of the freeze-thaw cycle, the saturated volumetric water content first decreases and then increases. Similarly, after several times of the freeze-thaw cycle, the structure is basically stable. The fitted Gardner model equations under different conditions were proved to be able to describe the SWCCs of the two targeted expansive soils.

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42

Pasban, Ali Asghar, and Behrouz Nonahal. "The Investigation of precision of analytical methods for determination of salt content in Iranian crude oils." Analytical Methods in Environmental Chemistry Journal 1, no. 01 (November 26, 2018): 23–28. http://dx.doi.org/10.24200/amecj.v1.i01.33.

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In crude oil analysis, the determination of salt content is one of the most important parameters especially for refining and exporting industries. In this study, extraction followed by volumetric titration and electrometric procedure are performed for determining salt content for several Iranian crude oils. Also, the effects of disturbing agents such as increasing associated water for determining salt in crude oil were investigated for both methods. The results show when water content in crude oil is less than 0.05 weight percent, both methods are equally accurate for determining salt content, but when there is an increase in associated water content in crude oil, the electrometric method followed by volumetric titration method shows more accurate results in comparison with the extraction procedure.

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43

Hanson, Anne-Marie, J. Roger Harris, Robert Wright, Alex Niemiera, and Naraine Persaud. "Water Content of a Pine-bark Growing Substrate in a Drying Mineral Soil." HortScience 39, no. 3 (June 2004): 591–94. http://dx.doi.org/10.21273/hortsci.39.3.591.

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Newly transplanted container-grown landscape plants are reported to require very frequent irrigation. However, container nurseries in the U.S. commonly use growing substrates that are mostly bark, even though the contribution of bark-based growing substrates to water relations of transplanted root balls is unknown. Therefore, a field experiment was undertaken to determine water relations of a pine-bark substrate (container removed) within a drying mineral soil over a three week period. A range of common production container sizes—3.7 L (#1), 7.5 L (#2), 21.9 L (#7), 50.6 L (#15), and 104.5 L (#25)—was used. The fraction of substrate volume that is water [total volumetric water (TVW)] within the top and middle zones of substrate was compared to TVW at corresponding depths of adjacent mineral soil. The fraction of substrate and soil volume that is plant-available water [plant-available volumetric water (PAVW)] was calculated by subtracting the fraction of substrate or soil volume below where water is unavailable to most plants (measured with pressure plates) [plant-unavailable volumetric water (PUVW)] from each TVW measurement. The pine-bark substrate had a PUVW of 0.32 compared to a PUVW of 0.06 for soil. Top sections of substrate dried to near zero PAVW 6 days after irrigation for all containers. Larger container sizes maintained higher PAVW in middle sections than smaller container sizes, and PAVW was always higher in the adjacent soil than in the embedded substrate. Overall, very little PAVW is held by the embedded pine-bark growing substrate, suggesting the need for container substrates with greater water retention once transplanted to mineral soils.

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44

Engelhart, G. J., L. Hildebrandt, E. Kostenidou, N. Mihalopoulos, N. M. Donahue, and S. N. Pandis. "Water content of aged aerosol." Atmospheric Chemistry and Physics 11, no. 3 (February 1, 2011): 911–20. http://dx.doi.org/10.5194/acp-11-911-2011.

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Abstract. The composition and physical properties of aged atmospheric aerosol were characterized at a remote sampling site on the northern coast of Crete, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-2008). A reduced Dry-Ambient Aerosol Size Spectrometer (DAASS) was deployed to measure the aerosol water content and volumetric growth factor of fine particulate matter. The particles remained wet even at relative humidity (RH) as low as 20%. The aerosol was acidic during most of the measurement campaign, which likely contributed to the water uptake at low RH. The water content observations were compared to the thermodynamic model E-AIM, neglecting any contribution of the organics to aerosol water content. There was good agreement between the water measurements and the model predictions. Adding the small amount of water associated with the organic aerosol based on monoterpene water absorption did not change the quality of the agreement. These results strongly suggest that the water uptake by aged organic aerosol is relatively small (a few percent of the total water for the conditions during FAME-08) and generally consistent with what has been observed in laboratory experiments. The water concentration measured by a Q-AMS was well correlated with the DAASS measurements and in good agreement with the predicted values for the RH of the Q-AMS inlet. This suggests that, at least for the conditions of the study, the Q-AMS can provide valuable information about the aerosol water concentrations if the sample is not dried.

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45

Abu-Hamdeh, Nidal H. "Specific Heat and Volumetric Heat Capacity of Granular Materials as Affected by Moisture and Density." Applied Mechanics and Materials 575 (June 2014): 103–7. http://dx.doi.org/10.4028/www.scientific.net/amm.575.103.

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The granular materials examined in this study were some Saudian soils. The effect of water content and bulk density on the specific heat and volumetric heat capacity of two Saudian soils (sand and loam) was investigated through laboratory studies. These laboratory experiments used the calorimetric method to determine specific heat of soils. For the type of soils studied, specific heat increased with increased moisture content. Also, volumetric heat capacity increased with increased moisture content and soil density. The volumetric heat capacity and specific heat of soils observed were compared with independent estimates made using derived theoretical relations. The differences between the observed and predicted results were very small. Loam soil generally had higher specific heat and volumetric heat capacity than sandy soil for the same moisture content and soil density.

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46

Chang, Kuo-Hsien, Jacqueline E. Powers, and Eric Lyons. "Water Restriction Impact on Surface Hardness and Soil Volumetric Water Content on Recreational Sports Fields." itsrj 13, no. 1 (2017): 614. http://dx.doi.org/10.2134/itsrj2016.09.0832.

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47

Zhen, Shuyang, and Stephanie E. Burnett. "Effects of Substrate Volumetric Water Content on English Lavender Morphology and Photosynthesis." HortScience 50, no. 6 (June 2015): 909–15. http://dx.doi.org/10.21273/hortsci.50.6.909.

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There is currently little information regarding the impact of soil moisture on morphology and physiology of English lavender (Lavandula angustifolia). Therefore, our goal was to determine the impact of substrate volumetric water content (θ = volume of water ÷ volume of substrate) on this plant. We grew ‘Munstead’ and ‘Hidcote’ lavender at one of four θ: 0.1, 0.2, 0.3, or 0.4 L·L−1 for 54 days using a capacitance sensor-automated irrigation system. Plant height, greatest width, inflorescence number, and total leaf number and area of both cultivars increased with increasing θ. Shoot fresh and dry weight of lavender irrigated at θ ≥ 0.3 L·L−1 was generally twice that of those grown at the lowest θ (0.1 L·L−1). Leaf-level instantaneous net photosynthetic rate (AN) and transpiration (E) of ‘Munstead’ decreased with decreasing θ. This reduction in AN was likely due to the concurrent reduction in stomatal conductance (gS) at lower θ. Similar reductions in AN, E, and gS of ‘Hidcote’ were observed at lower θ (0.2 and 0.3 L·L−1) 5 weeks after the initiation of the study, but not at the end of the study probably due to acclimation of ‘Hidcote’ to mild drought.

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48

Jackson, Scott H. "Comparison of calculated and measured volumetric water content at four field sites." Agricultural Water Management 58, no. 3 (February 2003): 209–22. http://dx.doi.org/10.1016/s0378-3774(02)00078-1.

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49

Mohamed, M. H. A., and K. V. Horoshenkov. "Airborne Acoustic Method to Determine the Volumetric Water Content of Unsaturated Sands." Journal of Geotechnical and Geoenvironmental Engineering 135, no. 12 (December 2009): 1872–82. http://dx.doi.org/10.1061/(asce)gt.1943-5606.0000168.

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50

Ceaglio, Elisabetta, Christoph Mitterer, Margherita Maggioni, Stefano Ferraris, Valerio Segor, and Michele Freppaz. "The role of soil volumetric liquid water content during snow gliding processes." Cold Regions Science and Technology 136 (April 2017): 17–29. http://dx.doi.org/10.1016/j.coldregions.2017.01.007.

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Journal articles on the topic 'Volumetric water content'

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