ESTIMATED SOIL WATER RESERVES APPLICABLE TO A WHEAT-FALLOW ROTATION FOR GENERALIZED SOIL AREAS MAPPED IN SOUTHERN SASKATCHEWAN

1984 ◽  
Vol 64 (4) ◽  
pp. 667-680 ◽  
Author(s):  
R. DE JONG ◽  
J. A. SHIELDS ◽  
W. K. SLY
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Holding Capacity ◽  
Climatic Data ◽  
Moisture Budget ◽  
Model Soil ◽  
Available Water ◽  
Soil Zone ◽  
Water Holding ◽  
Soil Moisture Budget

Long-term mean soil water reserves for a spring wheat-fallow rotation in the southern half of Saskatchewan were calculated using the Versatile Soil Moisture Budget. Four different available water-holding capacity classes and climatic data from 53 stations were used as input to the model. Soil water reserve data for the following times, seeding on 1 May in the crop year, at heading on 30 June, and on 1 May in the fallow year, were mapped. These were then combined with an available water-holding capacity map to portray in a single map the combined droughtiness due to climatic and soil attributes. Estimated soil water reserves compared well with measured data from one location in the Brown soil zone. The temporal and spatial changes in water reserves are discussed and related to summerfallowing. The maps provide information for use in making potential grain yield estimates. Key words: Soil water, wheat-fallow rotation, generalized soil areas, Saskatchewan, Versatile soil moisture budget

AVAILABLE WATER-HOLDING CAPACITY MAPS OF ALBERTA, SASKATCHEWAN AND MANITOBA

1988 ◽  
Vol 68 (1) ◽  
pp. 157-163 ◽  
Author(s):  
R. DE JONG ◽  
J. A. SHIELDS
Keyword(s):  
Key Words ◽  
Soil Water ◽  
Water Holding Capacity ◽  
Crop Modelling ◽  
Available Water ◽  
Soil Landscape ◽  
Water Holding

Available water-holding capacity (AWC) maps of Alberta, Saskatchewan and Manitoba were derived from Soil Landscape maps (1:1 million scale) by substituting AWC classes for soil textural classes. The maps provide information required for the geographical interpretation of soil water and crop modelling analyses. Key words: Available water-holding capacity, maps, texture

EFFECTS OF SOIL WATER MOVEMENT ON ACTUAL EVAPOTRANSPIRATION ESTIMATED FROM THE SOIL MOISTURE BUDGET

1970 ◽  
Vol 50 (3) ◽  
pp. 409-417 ◽  
Author(s):  
WAYNE R. ROUSE
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Movement ◽  
Potential Evapotranspiration ◽  
Sandy Loam ◽  
Spatial Variations ◽  
Actual Evapotranspiration ◽  
Moisture Budget ◽  
Loam Soil ◽  
Soil Moisture Budget

Actual evapotranspiration was estimated from the soil moisture budget for a grass-covered sandy loam soil at Simcoe, Ontario. Soil moisture was measured at 25 sites distributed over a 6-meter-square grid. The coefficient of variation for actual evapotranspiration estimated at all sites averaged 13% and rose as high as 19%. Average actual evapotranspiration exceeded both the Penman and Thornthwaite estimates of potential evapotranspiration for three of the six measuring intervals, due to deep seepage losses. The application of corrections for the vertical water movement, determined from experimentally derived matric suction and hydraulic conductivity data, gave a substantial deep seepage loss for some periods and a capillary uptake of soil water for others. Vertical losses and gains created errors of up to + 28 and − 29%, respectively, in the standard estimates of actual evapotranspiration. The large spatial variations in evapotranspiration estimates resulted from variations in volumetric soil moisture between sample points, apparently creating differences in the magnitude and direction of vertical water movement across the terminal depth. The horizontal flux of water between measuring points was relatively unimportant in accounting for the spatial variations.

ESTIMATED LONG-TERM SOIL MOISTURE VARIABILITY ON THE CANADIAN PRAIRIES

1988 ◽  
Vol 68 (2) ◽  
pp. 307-321 ◽  
Author(s):  
R. DE JONG ◽  
A. BOOTSMA
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Production Systems ◽  
Moisture Budget ◽  
Canadian Prairies ◽  
Seeding Date ◽  
Water Contents ◽  
Soil Moisture Budget ◽  
Soil Water Contents

Soil water contents under wheat production systems on the Canadian prairies were estimated using the Versatile Soil Moisture Budget, which was modified to include an estimated seeding date and a biometeorological time scale. Large year-to-year variability required the use of long term (60 yr) data to describe seasonal and probable occurrences of soil water contents for 27 stations. Regression and correlation analyses were used to simplify presentation of the data and to display their spatial distribution. On average, summerfallowing was most effective in conserving water in areas with intermediate spring soil water contents and on soils with a higher available water-holding capacity (AWC). In abnormally dry years (i.e., 10% probability) summerfallowing conserved more water in the wetter areas while increasing the AWCs had the greatest effect on conserved water in the intermediate areas. Soil water contents at heading were greater under wheat-fallow rotation compared to continuous wheat and increased with increasing AWCs. Water contents of less than 50% of AWC at heading occurred with a probability of 80% or higher in most areas, indicating some stress is experienced in most years. Summerfallowing lowered the probability only slightly on soils with a low AWC, but by 10–20% on the higher AWC soils. The probability of extreme water stress at heading (i.e. water contents ≤ 10% of AWC) ranged from 0% in the wettest areas to 40–60% in the driest climatic area. Key words: Soil water content, versatile soil moisture budget, summer fallowing, zonation, wheat (spring), seeding date

Patterns and simulation of soil water under different grazing management systems in central Alberta

2003 ◽  
Vol 83 (5) ◽  
pp. 601-614 ◽  
Author(s):  
E. Mapfumo ◽  
D. S. Chanasyk ◽  
V. S. Baron
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Research Centre ◽  
Moisture Budget ◽  
Model Errors ◽  
Soil Moisture Budget

A study was conducted at the Lacombe Research Centre to quantify and simulate the impacts of forage and grazing systems on soil water content. Four forages used in the study were alfalfa (Medicago sativa L.), a mixture of meadow bromegrass (Bromus riparius L.) and alfalfa, an annual pasture and an old grass pasture that was composed of mainly quackgrass (Elytrigia repens L.), smooth bromegrass (Bromus inermis L.) and Kentucky bluegrass (Poa pratensis L .). Within each 1.2-ha paddock were two grazing treatments: rotational grazed and ungrazed. Soil water measurements to a 65-cm depth were conducted between May and October of 1999 and 2000 using a neutron moisture probe. Total soil water was affected by forage species more than grazing. Actual evapotranspiration rates were 3-4 mm d-1 in both years. Simulation of daily volumetric soil water content (%) for each year was conducted using the Versatile Soil Moisture Budget (VB2000) model on grazed alfalfa, ungrazed alfalfa, grazed annual and ungrazed annual treatments. During calibration year of 1999, the overall modeling efficiency (EF) was 0.58 while, during the evaluation year it was 0.43. Further, simulations for alfalfa were better than those for annual treatments. These EF values are relatively low indicating substantial discrepancies between observed and simulated results, which could have been attributed to a combination of input data errors, model errors and propagation errors in output. Key words: Evapotranspiration, forages, model calibration, model evaluation, versatile soil moisture budget model

scholarly journals Water holding properties and soil water types in fine textured Vertisol soils of Thrace region in Turkey

2019 ◽  
Vol 52 (2) ◽  
pp. 247
Author(s):  
Recep Çakir
Keyword(s):  
Soil Water ◽  
Clay Content ◽  
Soil Samples ◽  
Water Holding Capacity ◽  
Membrane Extraction ◽  
Soil Profiles ◽  
Water Types ◽  
Model Soil ◽  
Water Holding ◽  
Thrace Region

<p>The study was carried out on 16 selected model soil profiles, located on lands covered with soils exhibiting vertic properties in Thrace Region of Turkey. Different horizons and/or sub-horizons of 16 characteristic soil profiles were evaluated in field or laboratory conditions in terms of water holding capacity and water types properties. Total of 105 soil samples were analyzed for routine physical characteristics. Soil water holding capacity was determined applying negative potentials (Ψ) of -0.33 bar, -15.5 bar and -31.5 bar (pF 2.54; 4.2 and 4.5), using a pressure-membrane extraction apparatus. In addition to gravitational, available, unavailable and hygroscopic soil water types, the soil samples were investigated also in terms of crystal-lattice water content. The highest amounts of the listed water types were determined in soils of Büyük Mandira, Türkgeldi and Seymen containing the highest rates of smectite clay mineral. The mass percentage (Pw) rates of the mentioned water types of the investigated profies varied in the ranges of 29.1–66.3%, 10–2.15%, 22.0–32.4%, 6.0–9.0% and 5.6–8.6%, respectively. Though the mass percentages of enumerated water types in the soils of Osmanli and Yeni Mahalle, all owning high sand and lower clay content on the other hand, are between 28.9–40.6%, 6.1–15.5%, 7.4–16.8%, 2.4–4.8% and 1.7–4.4%, respectively.</p>

scholarly journals Influence of Rice Husk Biochar on Water Holding Capacity of Soil in The Savannah Ecological Zone of Ghana

2019 ◽  
Vol 7 (6) ◽  
pp. 888
Author(s):  
Ammal Abukari
Keyword(s):  
Soil Moisture ◽  
Rice Husk ◽  
Management Practices ◽  
Vital Role ◽  
Water Holding Capacity ◽  
Ecological Zone ◽  
Crop Water ◽  
Available Water ◽  
Rice Husk Biochar ◽  
Water Holding

Soil moisture has a vital role in the cultivation of crops. Its sufficiency and availability to crop- water supplies depends on the management practices of soil and amount of available water to the soil. This study examines the influence of rice husk biochar on the water holding capacity of soil in the savannah ecological zone of Ghana. Increasing rate of rice husk biochar increased water-holding capacity of soils. 4t/ha rice husk biochar showed higher significant differences among the treatments. It is recommended that 4t/ha rice husk biochar should be applied to increase the water-holding capacity of the soil.

scholarly journals Estimation of soil water holding capacity with Random Forests for drought monitoring

2021 ◽  
Author(s):  
Yves Tramblay ◽  
Pere Quintana Seguí
Keyword(s):  
Soil Moisture ◽  
High Resolution ◽  
Soil Water ◽  
Random Forests ◽  
Land Surface ◽  
Water Holding Capacity ◽  
Drought Monitoring ◽  
Soil Maps ◽  
Soil Water Holding Capacity ◽  
Water Holding

Abstract. Soil moisture is a key variable for drought monitoring but soil moisture measurements networks are very scarce. Land-surface models can provide a valuable alternative to simulate soil moisture dynamics, but only a few countries have such modelling schemes implemented for monitoring soil moisture at high spatial resolution. In this study, a soil moisture accounting model (SMA) was regionalized over the Iberian Peninsula, taking as a reference the soil moisture simulated by a high-resolution land surface model. To estimate soil water holding capacity, the parameter required to run the SMA model, two approaches were compared: the direct estimation from European soil maps using pedotransfer functions, or an indirect estimation by a Machine Learning approach, Random Forests, using as predictors altitude, temperature, precipitation, evapotranspiration and land use. Results showed that the Random Forest model estimates are more robust, especially for estimating low soil moisture levels. Consequently, the proposed approach can provide an efficient way to simulate daily soil moisture and therefore monitor soil moisture droughts, in contexts where high-resolution soil maps are not available, as it relies on a set of covariates that can be reliably estimated from global databases.

A MOISTURE STRESS INDEX FOR WHEAT BY MEANS OF A MODULATED SOIL MOISTURE BUDGET

1968 ◽  
Vol 48 (5) ◽  
pp. 535-544 ◽  
Author(s):  
A. R. Mack ◽  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Stress Function ◽  
Potential Evapotranspiration ◽  
Moisture Stress ◽  
Moisture Distribution ◽  
Stress Index ◽  
Wheat Crop ◽  
Moisture Budget ◽  
Dough Stage ◽  
Soil Moisture Budget

Actual evapotranspiration (AE), soil moisture distribution, and moisture stress for a wheat crop (PE-AE) were estimated by the modulated soil moisture budget of Holmes and Robertson. The estimated soil moisture was reasonably well correlated with soil moisture measured weekly by means of gypsum blocks. Wheat yields from experimental plots in the corresponding area were related more closely to the moisture stress function (PE-AE: r = − 0.83), than to the seasonal precipitation (r = 0.62), the potential evapotranspiration (PE) or the evapotranspiration ratio (AE/PE). Regression analyses showed that the grain yields were reduced by an average of 156 (±sb = 40) kg/ha per cm of moisture stress from emergence to harvest, or by 311 and 69 kg/ha per cm of stress, from the fifth-leaf to the soft-dough stage and from the soft-dough stage to maturity, respectively. The moisture stress function may be used to characterize the soil–plant–atmosphere environment for the growing season of a crop. Precipitation and evapotranspiration data are presented annually for three standardized growing periods at Brandon from 1921 to 1963.

scholarly journals Soil Water Characteristics of Gleysols in the Bamenda (Cameroon) Wetlands and Implications for Agricultural Management Strategies

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Alice Mufur Magha ◽  
Primus Azinwi Tamfuh ◽  
Lionelle Estelle Mamdem ◽  
Marie Christy Shey Yefon ◽  
Bertrand Kenzong ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Water ◽  
Total Variance ◽  
Organic Carbon Content ◽  
Available Water ◽  
High Soil ◽  
Local Soil ◽  
Very High

Water budgeting in agriculture requires local soil moisture information as crops depend mainly on moisture available at root level. The present paper aims to evaluate the soil moisture characteristics of Gleysols in the Bamenda (Cameroon) wetlands and to evaluate the link between soil moisture content and selected soil characteristics affecting crop production. The work was conducted in the field and laboratory, and data were analyzed by simple descriptive statistics. The main results showed that the soils had a silty clayey to clayey texture, high bulk density, high soil organic carbon content, and high soil organic carbon stocks. The big difference between moisture contents at wilting point and at field capacity testified to very high plant-available water content. Also, the soils displayed very high contents of readily available water and water storage contents. The soil moisture characteristics give sigmoid curves and enabled noting that the Gleysols attain their full water saturation at a range of 57.68 to 91.70% of dry soil. Clay and SOC contents show a significant positive correlation with most of the soil moisture characteristics, indicating that these soil properties are important for soil water retention. Particle density, coarse fragments, and sand contents correlated negatively with the soil moisture characteristics, suggesting that they decrease soil water-holding capacity. The principal component analysis (PCA) enabled reducing 17 variables described to only three principal components (PCs) explaining 73.73% of the total variance; the first PC alone expressed 45.12% of the total variance, associating clay, SOC, and six soil moisture characteristics, thus portraying a deep correlation between these eight variables. Construction of contoured ditches, deep tillage, and raised ridges management techniques during the rainy season while channeling water from nearby water bodies into the farmland, opportunity cropping, and usage of water cans and other irrigation strategies are used during the dry season to combat water constraints.

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