scholarly journals Field Performance of Nine Soil Water Content Sensors on a Sandy Loam Soil in New Brunswick, Maritime Region, Canada

Sensors ◽  
2009 ◽  
Vol 9 (11) ◽  
pp. 9398-9413 ◽  
Author(s):  
Lien Chow ◽  
Zisheng Xing ◽  
Herb Rees ◽  
Fanrui Meng ◽  
John Monteith ◽  
...  
2017 ◽  
pp. 1.9-1.19 ◽  
Author(s):  
Afua Mante ◽  
Ramanathan Sri Ranjan

The HYDRUS (2D/3D) modeling tool was used to simulate water flow through subsurface-drained sandy loam soil under potato (Solanum tuberosum) cultivation in Southern Manitoba. The model was used to simulate water flow through a 2-D model domain of dimensions, 15 m width × 2.5 m depth. The model was calibrated and validated with field data measured during the growing season of year 2011 at the Hespler Farms, Winkler, Manitoba. Field measurements, including soil water content and watertable depth, for two test plots under subsurface free drainage were used for the calibration and validation. Weather data were also obtained to estimate reference crop evapotranspiration, which was used as input data in the model. Based on the reference crop evapotranspiration, and crop coefficient of the potato crop, the actual crop evapotranspiration was estimated and compared to the simulated actual crop evapotranspiration results. The results showed that the model was able to account for 50% to 78% of the variation in the estimated actual crop evapotranspiration. With respect to water flow through the soil, the observed soil water content and the simulated soil water content were compared using graphical and quantitative analysis. Based on the coefficient of determination (R2), the model accounted for 68% to 89% variation in the observed data. The intercept of the regression line varied from 0.01 to 0.08, and the slope, 0.75 to 0.99. The Nash–Sutcliffe modeling efficiency coefficient (NSE) varied from 0.62-0.89, the Percent bias (PBIAS) values varied from -1.99% to 1.16%. The root mean square error-observations standard deviation ratio (RSR) values varied from 0.33 to 0.61. The values for the evaluation parameters show that the model was able to simulate the water flow through the soil profile reasonably well.


1988 ◽  
Vol 68 (2) ◽  
pp. 405-416 ◽  
Author(s):  
D. R. COOTE ◽  
C. A. MALCOLM-McGOVERN ◽  
G. J. WALL ◽  
W. T. DICKINSON ◽  
R. P. RUDRA

Soil-erodibility indices were investigated in two regions of Ontario to evaluate their seasonal variation and differences between soil types. Shear strength and water-stable aggregates >0.5 mm were strongly negatively correlated with gravimetric soil water content for a Guelph sandy loam soil in southwestern Ontario. Similar variation of shear strength was estimated in three other southwestern Ontario surface soils as a result of seasonal changes in moisture content. Shear strength and aggregate stability increased as four eastern Ontario soils, ranging in texture from loamy sand to clay, dried and warmed following spring thaw. Laboratory incubation at constant temperature and water content showed that shear strength increased in two fine-textured soils with increasing degree days but changed very little in two coarse-textured soils. At the point-of-thaw in the field, all of the eastern Ontario soils exhibited very high values of the indices 1/shear strength and 1/aggregate stability, averaging approximately 15 times those of early July. During spring fallow and seed-bed to 10% canopy periods, the mean values of these indices were 3.7 and 1.4 times, respectively, those in early July. For winter-thaw conditions in the three southwestern Ontario soils, the index 1/shear strength averaged 17 times greater than in the summer. Spring values of this index averaged approximately twice those of summer. Results suggest that Ontario soils are much more susceptible to erosion under thaw and spring conditions than later during the growing season. Soil water content and soil warming may affect the re-establishment of resistance to erosion in soils rendered erodible by freezing, thawing, and saturation. Key words: Erodibility, shear strength, aggregate stability


2012 ◽  
Vol 111 ◽  
pp. 105-114 ◽  
Author(s):  
Basem Aljoumani ◽  
Jose A. Sànchez-Espigares ◽  
Nuria Cañameras ◽  
Ramon Josa ◽  
Joaquim Monserrat

2001 ◽  
Vol 81 (1) ◽  
pp. 45-52 ◽  
Author(s):  
R H Azooz ◽  
M A Arshad

In areas of the northwestern Canadian Prairies, barley and canola are grown in a short growing season with high rainfall variability. Excessively dry soil in conventional tillage (CT) in dry periods and excessively wet soil in no-tillage (NT) in wet periods could cause a significant decrease in crop production by influencing the availability of soil water. The effects of CT, NT and NT with a 7.5-cm residue-free strip on the planting rows (NTR) on soil water drying (–dW/dt) and recharge (dW/dt) rates were studied in 1992 and 1993 during wet and dry periods to evaluate the impact of NTR, NT and CT systems on soil moisture condition. The soils, Donnelly silt loam and Donnelly sandy loam (both Gray Luvisol) were selected and soil water content by depth was measured by time domain reflectometry. Water retained at 6 matric potentials from –5 to –160 kPa were observed. In the field study, –dW/dt was significantly greater in CT than in NT in the silt loam for the 0- to 30-cm layer during the first 34 d after planting in 1992. The 0- to 30-cm soil layer in CT and NTR dried faster than in NT during a period immediately following heavy rainfall in the silt loam in 1993. The drying coefficient (–Kd ) was significantly greater in CT and NTR than in NT in the silt loam soil in 1993 and in the sandy loam soil in 1992 in the top 30-cm depth. The recharge coefficient (Kr) was significantly greater in NT and NTR than in CT for the silt loam soil. The NTR system increased the –dW/dt by 1.2 × 10-2 to 12.1 × 10-2 cm d-1 in 1992 and 1993 in the silt loam soil and by 10.2 × 10-2 cm d-1 in 1993 in the sandy loam soil as compared with NT. The dW/dt was 8.1 × 10-2 cm d-1 greater in NTR in 1992 and 1993 in the silt loam soil and was 1.9 × 10-2 greater in NTR in 1992 than in CT in the sandy loam soil. The laboratory study indicated that NT soils retained more water than the CT soils. The NTR practice maintained better soil moisture conditions for crop growth than CT in dry periods than NT in wet periods. Compared with NT, the NTR avoided prolonged near-saturated soil conditions with increased soil drying rate under extremely wet soil. Key words: Water drying, water recharge, water depletion, wet and drying periods, hydraulic properties, soil capacity to retain water


Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 379
Author(s):  
Priscilla Johnston ◽  
Michael Braunack ◽  
Philip S. Casey ◽  
Keith L. Bristow ◽  
Raju Adhikari

This glasshouse pot experiment demonstrated that a new sprayable and degradable polymer reduced soil water evaporation and promoted cotton seedling emergence and establishment. The polymer was tested on two contrasting soils (sandy loam and clay), representative of those used to grow cotton in Australia. Changes in soil water content in non-treated and polymer-treated pots were monitored over 80 days, after surface or subsurface watering. Plant biomass, soil water content and soil chemical properties were determined at harvest. The polymer reduced soil water evaporation by up to 35% in sandy loam and up to 20% in clay, did not compromise seedling emergence and improved plant growth per unit water applied by up to 26.2%. The polymer underwent extensive degradation after 80 days to produce low molecular-weight polymers or oligomers and water-extractable silicon species that may have implications for plant nutrition.


2018 ◽  
Vol 1 (1) ◽  
pp. 8-14
Author(s):  
Bandi Hermawan ◽  
Pajrina Pajrina ◽  
Sumardi Sumardi ◽  
Indra Agustian

Most of the water loss from the soil profile occurred through the evapotranspiration process especially when the plant covers were under maximum growth periods.  This study aimed to apply a technique of measuring a dielectric variable for calculating soil water content and crop water use in the coarse and medium textured soils grown with upland rice.  A couple of wires were inserted into the soil repacked in a 10-kg polybag grown with upland rice, the electrical impedance representing the dielectric value was measured using an instrument called the impedance meter.  The impedance values were converted into the soil water content using a nonlinear regression model of ? = a.ebZ where a and b were constants.  Results showed that the proposed technique of measuring the electrical impedance has successfully been applied to calculate the soil water content and the water use by upland rice grown in loamy sand and sandy loam soils.  Cumulative water loss from loamy sand was about 4 L plant-1 higher for the coarse loamy sand in the first 30 days of a measurement period, but about 10 L plant-1 higher for finer sandy loam on the 90th day of the rice growth period.  Higher biomass of upland rice in the sandy loam soil could increase the evapotranspiration rates and be the main reason for higher water use in this soil.


2020 ◽  
Author(s):  
Doudou Li ◽  
Benye Xi ◽  
Liming Jia

<p>     Understanding the rules of soil water movement under drip irrigation can provide data support and theoretical basis for developing precise drip irrigation strategies. In this study, a two-years-old <em>Populus tomentosa </em>plantation under surface drip irrigation on sandy loam soil was selected to measure the dynamics of soil water potential (<span><em>ψ</em></span><em><sub>s</sub></em>), wetting front and soil water content (<span><em>θ</em></span>) during irrigation and water redistribution periods were investigated in field experiments. Then, the observed data in the field were used to evaluate the accuracy and feasibility of the HYDRUS-2D/3D model for simulating the short-term soil water movement. Besides, the validated model was used to simulate the dynamics of wetting front under different initial soil water content (<span><em>θ</em></span><em><sub>i</sub></em>). During irrigation, the variation of <span><em>ψ</em></span><em><sub>s</sub></em>, horizontal and vertical movement distances of the wetting front, and <span><em>θ</em></span> within the wetting volume with irrigation duration could be described by the logistic function (<em>R<sup>2</sup></em> = 0.99), the logarithm function (<em>R<sup>2</sup></em> = 0.99), the power function (<em>R<sup>2</sup></em> = 0.82), and the polynomial function (<em>R<sup>2</sup></em> = 0.99), respectively. At the end of irrigation, the horizontal and vertical movement distances of the wetting front reached 22.9 cm and 37.3 cm, respectively. The <span><em>ψ</em></span><em><sub>s</sub></em> and <span><em>θ</em></span> within the soil wetting volume were 61.6% and 30.9% higher than those at the start of the irrigation, respectively, but the <span><em>ψ</em></span><em><sub>s </sub></em>decreased to its initial level about 120 hours later after the stop of irrigation. The average deviations of the horizontal and vertical wetting radius between the simulated and measured values were 1.3 and 4.5 cm, respectively. The mean RMSE and RMAE of HYDRUS-2D/3D for simulating <span><em>θ</em></span> at the end of irrigation and during water redistribution were 0.021 cm<sup>3</sup>∙cm<sup>-3</sup> and 9.7%, respectively. The movement distances of wetting front in the experimental plantation under various soil drought degrees (soil water availabilities were 40%, 60%, 73% and 80%) were obtained through scenarios simulations using HYDRUS-2D/3D. And it was found that the wetting front could move further under higher <span><em>θ</em></span><em><sub>i</sub></em>, and the movement distance of the wetting front was always smaller in the horizontal direction than in the vertical direction under different <span><em>θ</em></span><em><sub>i </sub></em>conditions. Consequently, HYDRUS-2D/3D can be used to well simulate the short-term soil water movement in drip-irrigated young <em>P. tomentosa</em> plantations on sandy loam soil. In addition, the constructed figure (describes the variations of the horizontal and vertical soil wetting distances with the irrigation duration) can be used to determine the reasonable irrigation duration for the plantations of <em>P. tomentosa</em> and other tree species on sandy loam soil.</p>


1995 ◽  
Vol 75 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Marc O. Gasser ◽  
Marc R. Laverdière ◽  
Adrien N’dayegamiye

A 3-yr study (1988–1990) was conducted on a Beaurivage sandy loam soil located in St-Lambert, Québec, Canada, to evaluate the short-term effects of crop rotations and organic amendments on soil properties and potato yields (Solanum tuberosum, L.). Treatments consisted of yearly fall rye (Secale cereale, L.) as a green-manure cover crop, barley (Hordeum vulgare, L.) grown every 3-yr in potato crop rotation, partially humified bark residues and fresh tree clippings applied once at 100 m3 ha−1 in the beginning of the experiment, and continuous potato in monoculture used as check. Fertilizer rates were applied at 150, 100, 160 and 40 kg ha−1 rates for N, P2O5, K2O5 and Mg, respectively. Results indicated that more rapid changes of soil C content were observed with ligneous material incorporation than with fall rye and barley residue additions. Compared with fresh tree cuttings, partially humified bark induced rapid changes in soil organic C and cationic exchange capacity (CEC). A temporary soil structural stability improvement was observed in 1989 under fall rye cover crop. However soil bulk density increased significantly (P < 0.05) in these plots in 1990, and this was also related to low potato yields. Barley residues and ligneous amendments significantly improved soil water content during the critical flowering stage, and this increased potato yields and specific gravity (P < 0.05). In general, soil amendment would improve potato yields and quality through improved soil water content on a short-term. Key words: Barley, rye, rotation, cover crop, ligneous amendments, potato yields, soil physical and chemical properties


Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 598
Author(s):  
George Kargas ◽  
Paraskevi Londra ◽  
Marianthi Anastasatou ◽  
Nick Moustakas

Nowadays, the estimation of volumetric soil water content (θ) through apparent dielectric permittivity (εa) is the most widely used method. The purpose of this study is to investigate the effect of the high iron content of two sandy loam soils on estimating their water content using two dielectric sensors. These sensors are the WET sensor operating at 20 MHz and the ML2 sensor operating at 100 MHz. Experiments on specific soil columns, in the laboratory, by mixing different amounts of water in the soils to obtain a range of θ values under constant temperature conditions were conducted. Analysis of the results showed that both sensors, based on manufacturer calibration, led to overestimation of θ. This overestimation is due to the high measured values of εa by both sensors used. The WET sensor, operating at a lower frequency and being strongly affected by soil characteristics, showed the greatest overestimation. The difference of εa values between the two sensors ranged from 14 to 19 units at the maximum actual soil water content (θm). Compared to the Topp equation, the WET sensor measures 2.3 to 2.8 fold higher value of εa. From the results, it was shown that the relationship θm-εa0.5 remained linear even in the case of these soils with high iron content and the multi-point calibration (CALALL) is a good option where individual calibration is needed.


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