SEASONAL VARIATION OF ERODIBILITY INDICES BASED ON SHEAR STRENGTH AND AGGREGATE STABILITY IN SOME ONTARIO SOILS

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
Keyword(s):  
Shear Strength ◽  
Seasonal Variation ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Sandy Loam ◽  
Aggregate Stability ◽  
Mean Values ◽  
Loam Soil ◽  
Eastern Ontario

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

HYDRUS (2d/3d) simulation of water flow through sandy loam soil under potato cultivation in Southern Manitoba

2017 ◽  
pp. 1.9-1.19 ◽  
Author(s):  
Afua Mante ◽  
Ramanathan Sri Ranjan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Flow ◽  
Sandy Loam ◽  
Crop Evapotranspiration ◽  
Reference Crop Evapotranspiration ◽  
Loam Soil ◽  
Flow Through ◽  
Reference Crop

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.

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 ◽  
...  
Keyword(s):  
New Brunswick ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Sandy Loam ◽  
Field Performance ◽  
Sandy Loam Soil ◽  
Loam Soil ◽  
Maritime Region

scholarly journals Determining the Shear Strength and Permeability of Soils for Engineering of New Paddy Field Construction in a Hilly Mountainous Region of Southwestern China

2020 ◽  
Vol 17 (5) ◽  
pp. 1555
Author(s):  
Zhen Han ◽  
Jiangwen Li ◽  
Pengfei Gao ◽  
Bangwei Huang ◽  
Jiupai Ni ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Water Content ◽  
Engineering Design ◽  
Soil Water ◽  
Soil Water Content ◽  
Paddy Field ◽  
Friction Angle ◽  
Strength Properties ◽  
Mountainous Region

As a constructed wetland ecosystem, paddy field plays an irreplaceable role in flood storage and detention, groundwater replenishment, environmental protection, and ecological balance maintenance. New paddy field construction can give full play to the production and ecological functions of paddy field and can adjust the development structure of the agricultural industry effectively. The soil properties of shear strength and permeability, which provide a theoretical basis for engineering design, construction, and post-operation, are important indexes in the site selection of new paddy field. The shear strength and permeability properties of soils from different land use types (vegetable field, gentle slope dryland, corn field, grapery, and abandoned dryland) for engineering new paddy field construction were investigated in this study. The results showed that the soil water content had a significant effect on the soil shear strength, internal friction angle, and cohesion. The total pressure required for soil destruction decreased with increasing water content under the same vertical pressure, resulting in easier destruction of soils. The internal friction angle decreased with increasing soil water content, and the soil cohesion first increased and then decreased with increasing soil water content. Considering that paddy fields were flooded for a long time, the soil strength properties had certain water sensitivity. Effective measures must be taken to reduce the change in soil water content, so as to ensure the stability of the embankment foundation, roadside ditch foundation, and cutting slope. In addition, the influence of changing soil water content on the strength properties of paddy soils should be fully considered in engineering design and construction, and the soil bulk density at the plough pan should reach at least 1.5 g cm−3 or more to ensure better water retention and the anti-seepage function of paddy field. The study can provide construction technology for engineering new paddy field construction in a hilly mountainous region of southwestern China.

Time series outlier and intervention analysis: Irrigation management influences on soil water content in silty loam soil

2012 ◽  
Vol 111 ◽  
pp. 105-114 ◽  
Author(s):  
Basem Aljoumani ◽  
Jose A. Sànchez-Espigares ◽  
Nuria Cañameras ◽  
Ramon Josa ◽  
Joaquim Monserrat
Keyword(s):  
Time Series ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Irrigation Management ◽  
Intervention Analysis ◽  
Silty Loam ◽  
Loam Soil

scholarly journals Glasshouse study of a sprayable, degradable polymer to reduce water use in cotton establishment

Soil Research ◽  
2020 ◽  
Vol 58 (4) ◽  
pp. 379
Author(s):  
Priscilla Johnston ◽  
Michael Braunack ◽  
Philip S. Casey ◽  
Keith L. Bristow ◽  
Raju Adhikari
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Plant Biomass ◽  
Sandy Loam ◽  
Seedling Emergence ◽  
Chemical Properties ◽  
Water Evaporation ◽  
Degradable Polymer ◽  
Extensive Degradation

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.

scholarly journals Application of a Dielectric Measurement Technique for Calculating Water Loss from Two Texture-contrasting Soils Grown with Upland Rice

2018 ◽  
Vol 1 (1) ◽  
pp. 8-14
Author(s):  
Bandi Hermawan ◽  
Pajrina Pajrina ◽  
Sumardi Sumardi ◽  
Indra Agustian
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Use ◽  
Water Loss ◽  
Electrical Impedance ◽  
Upland Rice ◽  
Sandy Loam ◽  
Dielectric Measurement ◽  
Loamy Sand

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.

scholarly journals State-space approach to evaluate the relation between soil physical and chemical properties

2004 ◽  
Vol 28 (1) ◽  
pp. 49-58 ◽  
Author(s):  
L. C. Timm ◽  
K. Reichardt ◽  
J. C. M. Oliveira ◽  
F. A. M. Cassaro ◽  
T. T. Tominaga ◽  
...  
Keyword(s):  
State Space ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Chemical Properties ◽  
Aggregate Stability ◽  
Clay Content ◽  
State Space Approach ◽  
Physical And Chemical ◽  
Space Approach

The state-space approach is used to evaluate the relation between soil physical and chemical properties in an area cultivated with sugarcane. The experiment was carried out on a Rhodic Kandiudalf in Piracicaba, State of São Paulo, Brazil. Sugarcane was planted on an area of 0.21 ha i.e., in 15 rows 100 m long, spaced 1.4 m. Soil water content, soil organic matter, clay content and aggregate stability were sampled along a transect of 84 points, meter by meter. The state-space approach is used to evaluate how the soil water content is affected by itself and by soil organic matter, clay content, and aggregate stability of neighboring locations, in different combinations, aiming to contribute to a better understanding of the relation among these variables in the soil. Results show that soil water contents were successfully estimated by this approach. Best performances were found when the estimate of soil water content at locations i was related to soil water content, clay content and aggregate stability at locations i-1. Results also indicate that this state-space model using all series describes the soil water content better than any equivalent multiple regression equation.

Short-term effects of crop rotations and wood-residue amendments on potato yields and soil properties of a sandy loam soil

1995 ◽  
Vol 75 (3) ◽  
pp. 385-390 ◽  
Author(s):  
Marc O. Gasser ◽  
Marc R. Laverdière ◽  
Adrien N’dayegamiye
Keyword(s):  
Soil Properties ◽  
Water Content ◽  
Soil Water Content ◽  
Cover Crop ◽  
Sandy Loam ◽  
Crop Rotations ◽  
Short Term ◽  
Rapid Changes ◽  
Loam Soil ◽  
Potato Yields

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

scholarly journals The Effect of Soil Iron on the Estimation of Soil Water Content Using Dielectric Sensors

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 598
Author(s):  
George Kargas ◽  
Paraskevi Londra ◽  
Marianthi Anastasatou ◽  
Nick Moustakas
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Iron Content ◽  
Sandy Loam ◽  
High Iron Content ◽  
Volumetric Soil Water Content ◽  
High Iron ◽  
The Difference ◽  
Dielectric Sensors

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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