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

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

Quantification of Available Water Capacity Comparing Standard Methods and a Pedostructure Method on a Weakly Structured Soil

2019 ◽  
Vol 62 (2) ◽  
pp. 289-301
Author(s):  
Amjad T. Assi ◽  
Rabi H. Mohtar ◽  
Erik F. Braudeau ◽  
Cristine L. S. Morgan
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Field Capacity ◽  
Soil Aggregate ◽  
Pedotransfer Functions ◽  
Water Retention Curve ◽  
Aggregate Structure ◽  
Standard Methods ◽  
Available Water ◽  
Water Holding

Abstract. The purpose of this study was to evaluate the use of the pedostructure concept to determine the soil available water capacity, specifically the field capacity (FC). Pedostructure describes the soil aggregate structure and its thermodynamic interaction with water. Specifically, this work compared the calculation of soil water-holding properties based on the pedostructure concept with other standard methods for determining FC and permanent wilting point (PWP). The standard methods evaluated were the FAO texture estimate (FAO method), the Saxton-Rawls pedotransfer functions (PTFs method), and the water content at predefined soil suction (330 and 15,000 hPa) as measured with a pressure plate apparatus (PP method). Additionally, two pedostructure methods were assessed: the thermodynamic water retention curve (TWRC method) and the thermodynamic pedostructure (TPC method). Undisturbed loamy fine sand soil from a field in Millican, Texas, was analyzed at both the Ap and E horizons. The results showed that the estimated water content at FC and PWP for the three standard methods and for the TWRC method were in relative agreement. However, the TPC method used characteristic transition points in the modeled contents of different water pools in the soil aggregate and was higher for the Ap horizon, but in agreement with the other methods for the E horizon. For example, for the Ap horizon of the soil analyzed in this study, the FC estimated with the standard and TWRC methods ranged from 0.073 to 0.150 m3H2O m-3soil, while the TPC method estimate was 0.221 m3H2O m-3soil. Overall, the different methods showed good agreement in estimating the available water; however, the results also showed some variations in these estimates. It is clear that the TPC method has advantages over the other methods in considering the soil aggregate structure and modeling the soil water content within the aggregate structure. The thermodynamic nature of the TPC method enabled the use of both the soil shrinkage curve and the water retention curve in a weakly structured soil. It is expected that the TPC method would provide more comprehensive advances in understanding the soil water-holding properties of structured soils with higher clay contents. Keywords: Available water, Field capacity, Pedostructure, Pedotransfer functions, Permanent wilting point.

scholarly journals Comparison of three models fitting the soil water retention curves in a degraded alpine meadow region

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tao Pan ◽  
Shuai Hou ◽  
Yujie Liu ◽  
Qinghua Tan
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Alpine Meadow ◽  
Soil Depth ◽  
Water Holding Capacity ◽  
Curve Shape ◽  
Soil Water Retention ◽  
Soil Water Holding Capacity ◽  
Water Holding ◽  
Gardner Model

AbstractSoil water retention curve (SWRC) plays an important role in simulating soil water movement and assessing soil water holding capacity and availability. Comparison of fitness between different models to determine the best SWRC model of specific regions is required. In this study, three popular models, van Genuchten, Brooks Corey and Gardner model, were selected for comparing in a degraded alpine meadow region on the eastern Tibetan Plateau. Fitness, error distribution along with key parameters were compared. For each soil horizon, the soil moisture content at all soil water potentials decreased consistently with degradation, thereby integrally moving the SWRCs of all soil depths downward with degradation. The differences in SWRCs across various degradation degrees diminished along with soil depth and soil water potential. The Adj.r2 values of van Genuchten, Brooks Corey and Gardner models ranged in 0.971–0.995, 0.958–0.997, and 0.688–0.909, respectively. The van Genuchten and Brooks Corey models significantly (p < 0.05) outperformed the Gardner model, and have no significant differences in fitness. The fitness of all three models showed no significant changes with degradation. Regardless of degradation degree and soil depth, the fitting error of van Genuchten and Brooks Corey models was mainly distributed in the higher (from –100 hPa to –500 hPa) and lower (below –10000 hPa) potential sections. With regard to the parameters of van Genuchten and Brooks Corey models, the field capacity (θs), and permanent wilting moisture were highly coherent with Adj.r2 values of higher than 0.98, while the curve shape parameter (θr), and air entry pressure of the Brooks Corey model were much lower than those of the van Genuchten model with Adj.r2 values of lower than 0.91. The SWRCs with varying degrees of degradation are best fitted by both van Genuchten and Brooks Corey models but cannot be fitted by Gardner model. Soil water holding capacity decreased with degradation especially in the top soil (0 cm to 30 cm), but the curve shape of all SWRCs did not change significantly with degradation.

scholarly journals Analysis of soil and vegetation patterns in semi-arid Mediterranean landscapes by way of a conceptual water balance model

2008 ◽  
Vol 12 (3) ◽  
pp. 899-911 ◽  
Author(s):  
I. Portoghese ◽  
V. Iacobellis ◽  
M. Sivapalan
Keyword(s):  
Water Balance ◽  
Soil Water ◽  
Water Holding Capacity ◽  
Sensitivity Analyses ◽  
Vegetation Types ◽  
Study Region ◽  
Mediterranean Landscapes ◽  
Soil Water Holding Capacity ◽  
Water Holding ◽  
Semi Arid

Abstract. This paper investigates the impact of various vegetation types on water balance variability in semi-arid Mediterranean landscapes, and the different strategies they may have developed to succeed in such water-limited environments. The existence of preferential associations between soil water holding capacity and vegetation species is assessed through an extensive soil geo-database focused on a study region in Southern Italy. Water balance constraints that dominate the organization of landscapes are investigated by a conceptual bucket approach. The temporal water balance dynamics are modelled, with vegetation water use efficiency being parameterized through the use of empirically obtained crop coefficients as surrogates of vegetation behavior in various developmental stages. Sensitivity analyses with respect to the root zone depth and soil water holding capacity are carried out with the aim of explaining the existence of preferential soil-vegetation associations and, hence, the spatial distribution of vegetation types within the study region. Based on these sensitivity analyses the degrees of suitability and adaptability of each vegetation type to parts of the study region are explored with respect of the soil water holding capacity, and the model results were found consistent with the observed affinity patterns.

Soil water holding capacity under four typical ecosystems in Wuyunjie Nature Reserve of Hunan Province

2012 ◽  
Vol 32 (2) ◽  
pp. 538-547 ◽  
Author(s):  
潘春翔 PAN Chunxiang ◽  
李裕元 LI Yuyuan ◽  
彭亿 PENG Yi ◽  
高茹 GAO Ru ◽  
吴金水 WU Jinshui
Keyword(s):  
Soil Water ◽  
Nature Reserve ◽  
Water Holding Capacity ◽  
Hunan Province ◽  
Soil Water Holding Capacity ◽  
Water Holding

scholarly journals Mapping soil water holding capacity over large areas to predict potential production of forest stands

Geoderma ◽  
2011 ◽  
Vol 160 (3-4) ◽  
pp. 355-366 ◽  
Author(s):  
Christian Piedallu ◽  
Jean-Claude Gégout ◽  
Ary Bruand ◽  
Ingrid Seynave
Keyword(s):  
Soil Water ◽  
Water Holding Capacity ◽  
Forest Stands ◽  
Potential Production ◽  
Soil Water Holding Capacity ◽  
Water Holding

Site Quality Evaluation Models for Aspen (Populustremuloides Michx.) in Wisconsin

1975 ◽  
Vol 5 (4) ◽  
pp. 523-528 ◽  
Author(s):  
James S. Fralish ◽  
Orie L. Loucks
Keyword(s):  
Site Index ◽  
Water Holding Capacity ◽  
Site Quality ◽  
Quaking Aspen ◽  
North Central ◽  
Available Water ◽  
Soil Calcium ◽  
Calcium Magnesium ◽  
Regression Techniques ◽  
Water Holding

Soil and site relationships were studied in 32 mature quaking aspen (Populustremuloides Michx.) communities in north central Wisconsin. Multiple linear regression techniques indicated that soil texture, available water-holding capacity, water-table depth, and stand exposure were the most important factors controlling site index. Two models developed from combinations of these factors accounted for 62% of the variation in site index. Values for soil calcium, magnesium, potassium, and phosphorus were corrected for bulk density and summed to 12-, 24-, 36-, and 60-in. depths. When included in additional models, only magnesium to a 60-in. depth was found to have additional effect on aspen growth over and above that implicit in available water-holding capacity. The models were validated using 10 additional mature aspen stands and then applied to data from 10 stands in early stages of deterioration.

scholarly journals Effects of water deficit on the growth and yield formation of maize (Zea mays L.)

2017 ◽  
pp. 143-148
Author(s):  
Mahama Salifu
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Deficit ◽  
Crop Production ◽  
Water Holding Capacity ◽  
Field Soil ◽  
The World ◽  
Soil Water Holding Capacity ◽  
Water Holding

Maize (Zea mays L.) is the most important consuming cereal crop in the world after rice and wheat. This requires an understanding of various management practices as well as conditions that affect maize crop performance. Water deficit stress during crop production is one of the most serious threats to crop production in most parts of the world and drought stress or water deficit is an inevitable and recurring feature of global agriculture and it is against this background that field study of crops response to water deficit is very important to crop producer and researchers to maximize yield and improve crop production in this era of unpredicted climatic changes the world over.A pot experiment was carried out to determine the effects of water deficit on growth and yield formation of maize. Two maize cultivars were used Xundan20 and Zhongdan5485. Three levels of soil water content were used in two stages of water control levels at two stages of the maize plant development1. The JOINTING STAGE: A. CONTROL (CK) soil water content: from 70% to 80% of soil water holding capacity at the field, soil water content: from 55% to 65% of soil water holding capacity at the field, soil water content: from 40% to 50% of the Soil water holding capacity at the field.2. The BIG FLARE PERIOD: A. CONTROL (CK) soil water content: from 75% to 85% of soil water holding capacity at the field, soil water content: from 58% to 68% of soil water holding capacity at the field, soil water content: from 45% to 55% of the soil water holding capacity at the field.This research mainly studied the effects of water deficit on physiological, morphology and the agronomical characteristics of the maize plant at the different water stress levels.The importance of these results in this experiment will enable plant producers to focus and have a fair idea as to which stage of the maize plant’s development that much attention must be given to in terms of water supply.

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