Moisture characteristics of irrigated Mallee soils in South Australia

1985 ◽  
Vol 25 (1) ◽  
pp. 209 ◽  
Author(s):  
GJ Cock
Keyword(s):  
Soil Moisture ◽  
Bulk Density ◽  
South Australia ◽  
Small Variation ◽  
Field Capacity ◽  
Undisturbed Samples ◽  
Moisture Storage ◽  
Wilting Point ◽  
Soil Groups

The soil moisture characteristics of undisturbed samples of Mallee soils, taken from typical profiles of the Riverland district neat Berri in South Australia, were determined. Samples were grouped according to texture and bulk density and, for each group, the moisture storage between matric potentials was derived. Over the usual range of soil moisture tensions (-0 to 40kPa) these showed only small variation between soil groups since, while moisture storage at field capacity and at wilting point does vary with texture; 50 to 60 mm/m is available between field capacity (-7 kPa) and the re-irrigation point (-30 to 40kPa) in all soils.

Dark Island heath (Ninety-mile Plain, South Australia). V. The water relationships in heath vegetation and pastures on the Makin sand

1957 ◽  
Vol 5 (2) ◽  
pp. 151 ◽  
Author(s):  
RL Specht
Keyword(s):  
Soil Moisture ◽  
Balance Sheet ◽  
South Australia ◽  
Field Capacity ◽  
Severe Drought ◽  
Soil Moisture Storage ◽  
Drought Conditions ◽  
Moisture Storage ◽  
Medicago Sativa L ◽  
Soil Moisture Status

Heath vegetation shows a major flush of growth during the mediterraneantype summer season, a time when calculations of the soil moisture storage by the techniques of Thornthwaite (1948) or Prescott, Collins, and Shirpurkar (1952) indicate that severe drought conditions should oocur. Monthly observations on the moisture status of the Makin sand under heath vegetation and, for comparison, under various pastures are therefore recorded. The problems of obtaining an accurate water balance-sheet for such a heterogeneous vegetation as the heath are discussed. Difficulties in the use of the various techniques for measuring soil moisture in sand, which has a low pF of 1.85 at field capacity, are enumerated. The following relationships were found between the evapotranspiration index (Itr = Etr / Ew0.75) and the available water (W). These data were calculated for 6 ft of sand. (i) Heath vegetation (10–14 years old) log (2.4–Itr) = 0.420–0.0383 W (ii) Heath vegetation (burnt) log (2.4–Itr) = 0.461–0.0380 W (iii) Oenothera odorata Jacq. pasture log (2.4–Itr) = 0.395–0.0269 W (iv) Medicago sativa L. pasture log (2.4–Itr) = 0.390–0.0270 W (v) Ehrharta calycina Sm. pasture log (2.4–Itr) = 0.400–0.0339 W From these equations the mean monthly quantities of rainfall which may be stored in 6 ft of sand under the various treatments described were calculated. Drought conditions are shown to occur in December and January, but are relieved in the later months of summer. Even if the stored moisture below 8 ft is considered, the soil moisture status would be expected to be just sufficient to maintain the vegetation in a "dormant" state, and yet the major growth of the heath vegetation occurs at this time. The calculated mean annual values of Itr range from 0.53 to 0.60 for these perennial communities. Close approximations to the actual soil moisture status can be obtained by substituting these values for K in Prescott's formula for potential evaporation, i.e. Etr = K x Ew0.75. Supplementary data on transpiration, growth, and the root systems of the pastures are also included.

scholarly journals HUBUNGAN KETERSEDIAAN AIR TANAH DAN SIFAT-SIFAT DASAR FISIKA TANAH

2004 ◽  
Vol 6 (2) ◽  
pp. 46-50
Author(s):  
Kukuh Murtilaksono ◽  
Enny Dwi Wahyuni
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Organic Matter Content ◽  
Clay Content ◽  
Total Porosity ◽  
Field Capacity ◽  
Sand Content ◽  
Wilting Point

This research was conducted to study relationship between soil moisture content and soil physical characteristics that affected the moisture.The soil samples were collected from 22 scattered sites of West Java and Central Java. Analysis of soil physical properties (texture, bulk density, particle density, total porosity and soil moisture retention) and soil chemical property (organic matter) was conducted at the laboratory of Department of Soil Sciences, Faculty of Agriculture, Bogor Agricultural University. Analysis of simple linier regression was applied to know the correlation between soil moisture content and other basic soil physical properties.Availability of soil moisture (pF 4.20 – pF 2.54) significantly correlated with organic matter, total porosity, and micro pores. The higher organic matter content as well as total porosity and micro pores the higher available soil moisture. Soil moisture of field capacity significantly correlated with clay content, sand content, micro and macro pores. The higher clay content and micro pores the higher soil moisture of field capacity. In the contrary, the higher macro pores and sand content the lower the field capacity. Soil moisture of wilting point significantly correlated with clay content and macro pores. The higher clay content the higher the wilting point, while the higher macro pores the lower soil moisture of wilting point. Keywords : Available soil water, field capacity, organic matter, soil pores, wilting point

scholarly journals Hydropedological parameters limiting soil moisture regime floodplain ecosystems of south Moravia

2005 ◽  
Vol 53 (1) ◽  
pp. 71-84
Author(s):  
Ladislav Kubík
Keyword(s):  
Soil Moisture ◽  
Water Retention ◽  
Humus Content ◽  
Field Capacity ◽  
Pedotransfer Functions ◽  
Physical Parameters ◽  
Moisture Regime ◽  
Floodplain Ecosystems ◽  
Soil Moisture Regime ◽  
Wilting Point

Soil moisture regime of floodplain ecosystems in southern Moravia is considerably influenced and greatly changed by human activities. It can be changed negatively by water management engineering or positively by landscape revitalizations. The paper deals with problems of hydropedological characteristics (hydrolimits) limiting soil moisture regime and solves effect of hydrological factors on soil moisture regime in the floodplain ecosystems. Attention is paid especially to water retention curves and to hydrolimits – wilting point and field capacity. They can be acquired either directly by slow laboratory assessment, derivation from the water retention curves or indirectly by calculation using pedotransfer functions (PTF). This indirect assessment uses hydrolimit dependency on better available soil physical parameters namely soil granularity, bulk density and humus content. The aim is to calculate PTF for wilting point and field capacity and to compare them with measured values. The paper documents suitableness utilization of PTF for the region of interest. The results of correlation and regression analysis for soil moisture and groundwater table are furthermore presented.

The Influence of Soil Moisture on the Foliar Activity of Diclofop

Weed Science ◽  
1980 ◽  
Vol 28 (5) ◽  
pp. 534-539 ◽  
Author(s):  
W. A. Dortenzio ◽  
R. F. Norris
Keyword(s):  
Soil Moisture ◽  
Near Field ◽  
Field Capacity ◽  
Herbicide Application ◽  
Wild Oats ◽  
High Soil Moisture ◽  
Herbicide Activity ◽  
Moisture Conditions ◽  
Soil Moisture Status ◽  
Wilting Point

Loss in activity of foliar-applied methyl ester of diclofop {2-[4-(2,4-dichlorophenoxy)phenoxy] propanoic acid} occurred under low soil moisture conditions. A loss in control of yellow foxtail [Setaria lutescens(Weigel) Hubb.], wild oats (Avena fatuaL.), little-seed canarygrass (Phalaris minorRetz.), and barnyardgrass [Echinochloa crus-galli(L.) Beauv.], was observed under greenhouse and growth chamber conditions. When soil was maintained at 2 to 3% above wilting point as compared to near field capacity, herbicide activity was decreased by 15 to 50%. High soil moisture (at or above 67% of field capacity) for at least 2 to 4 days following treatment was needed to achieve maximum effectiveness of the herbicide. Daily furrow irrigations for a period of 10 days following treatment of barnyardgrass in the field resulted in highest activity as compared to that under single irrigation regimes within the 10-day period. The effect of low soil moisture was minimized by increased rates of herbicide application. Hoe-29152 {methyl-2-[4-(4-trifluoromethylphenoxy)phenoxy] propanoate} showed similar losses in activity associated with low soil moisture. No consistent changes in uptake or translocation of14C-labeled diclofop could be detected in association with altered soil moisture status.

GERMINATION AND SURVIVAL OF COLORADO SPRUCE, SCOTS PINE, CARAGANA, AND SIBERIAN ELM AT FOUR SALINITY AND TWO MOISTURE LEVELS

1966 ◽  
Vol 46 (1) ◽  
pp. 1-7 ◽  
Author(s):  
C. H. E. Werkhoven ◽  
P. J. Salisbury ◽  
W. H. Cram
Keyword(s):  
Soil Moisture ◽  
Scots Pine ◽  
Seedling Survival ◽  
Field Capacity ◽  
Coniferous Species ◽  
Picea Pungens ◽  
Greenhouse Study ◽  
Salinity Levels ◽  
Caragana Arborescens ◽  
Wilting Point

In a greenhouse study, salinity levels of ECe = 1, 4, 7, and 10 mmhos/cm at 25° were used to test the salinity tolerance of Colorado spruce (Picea pungens Engelm.), Scots pine (Pinus sylvestris L.), caragana (Caragana arborescens Lam.), and Siberian elm (Ulmus pumila L.) seedlings at two levels of soil moisture. Emergence, survival, plant height, and dry-matter yield were used as the response criteria.The deciduous species were more salt-tolerant than the coniferous species. In terms of survival, an ECe value of between 7 and 10 mmhos appeared to be critical for caragana and elm in a soil with a moisture content of about midway between the wilting point and field capacity. The corresponding values for spruce and pine were closer to 4 and 6 mmhos respectively. Seedling survival was markedly improved by maintaining the soil moisture level at field capacity.

EFFECT OF SOIL WATER CONTENT ON THE WINTER SURVIVAL OF WINTER WHEAT, RYE AND TRITICALE

1990 ◽  
Vol 70 (3) ◽  
pp. 667-675 ◽  
Author(s):  
YVES CLOUTIER ◽  
ANDRÉ COMEAU ◽  
MICHÈLE BERNIER-CARDOU ◽  
DENIS A. ANGERS
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Winter Wheat ◽  
Soil Temperature ◽  
Water Content ◽  
Field Capacity ◽  
Winter Rye ◽  
Winter Cereal ◽  
Ice Encasement ◽  
Wilting Point

A field study was conducted to determine the effect of soil moisture on the survival of three winter cereal species. Treatments were applied by watering and weighing the soil to the desired water content. Plants were overwintered in a plastic greenhouse in 1988 and in 1989, in which the air was not heated, but the soil was slightly heated on cold days to avoid very low temperatures. Soil temperature did not fall below −16 °C. Soil temperature rate of change was dependent on moisture content. Puma winter rye and Otrastajuskaja 38 winter wheat were the hardiest, followed by Wintri winter triticale and Norstar winter wheat. Harus winter wheat was less hardy, and Champlein winter wheat was totally winter killed. The highest survival rate was obtained at moderate to high soil moisture content. The soil contained 44% water at field capacity and 19% at the wilting point. The drier the soil in the range 13–23%, the greater the mortality indicating a negative effect of long-term drought on plant survival. By contrast, the wettest treatments: 58% and partial ice encasement, did not reduce survival. However, total ice encasement killed 50–75% of the plants depending on the cultivar. There was an interaction between cultivar and moisture treatment. The data suggest that a moisture level intermediate between the wilting point and field capacity should be sought in studies of cold hardiness.Key words: Moisture, winterkill, ice encasement, wheat, rye, triticale

scholarly journals Impact of soil moisture over Palmer Drought Severity Index and its future projections in Brazil

RBRH ◽  
2017 ◽  
Vol 22 (0) ◽  
Author(s):  
Luciana Rossato ◽  
José Antônio Marengo ◽  
Carlos Frederico de Angelis ◽  
Luciana Bassi Marinho Pires ◽  
Eduardo Mario Mendiondo
Keyword(s):  
Soil Moisture ◽  
Radiative Forcing ◽  
Water Storage ◽  
Field Capacity ◽  
Severity Index ◽  
Climate Projections ◽  
Future Projections ◽  
Water Conditions ◽  
The Impact ◽  
Wilting Point

ABSTRACT Soil moisture is a main factor for the study of drought impacts on vegetation. Drought is a regional phenomenon and affects the food security more than any other natural disaster. Currently, the monitoring of different types of drought is based on indexes that standardize in temporal and regional level allowing, thus, comparison of water conditions in different areas. Therefore, in order to assess the impact of soil moisture during periods of drought, drought Palmer Severity Index was estimated for the entire region of the territory. For this were used meteorological data (rainfall and evapotranspiration) and soil (field capacity, permanent wilting point and water storage in the soil). The data field capacity and wilting point were obtained from the physical properties of soil; while the water storage in soil was calculated considering the water balance model. The results of the PSDI were evaluated during the years 2000 to 2015, which correspond to periods with and without occurrence of drought. In order to assess the future drought projections, considering the set of the Coupled Model Intercomparison rainfall data Project Phase 5 (CMIP5). Climate projections precipitation in CMIP5 for the period 2071-2100 was extracted generating entitled forcing scenarios Representative Concentration Pathways - RCPs, and referred to as RCOP 8.5, corresponding to an approximate radiative forcing the end the twenty-first century of 8.5 Wm-2. The results showed that the PDSI is directly associated with climatological patterns of precipitation and soil moisture in any spatial and temporal scale (including future projections). Therefore, it is concluded that the PDSI is an important index to assess soil moisture different water conditions, as well as the association with economic and social information to create risk maps for subsidies to decision makers.

Statistical equations for estimating field capacity, wilting point and available water capacity of soils from their saturation percentage

1988 ◽  
Vol 110 (3) ◽  
pp. 515-520 ◽  
Author(s):  
I. S. Dahiya ◽  
D. J. Dahiya ◽  
M. S. Kuhad ◽  
S. P. S. Karwasra
Keyword(s):  
Soil Moisture ◽  
Estimation Error ◽  
Chemical Properties ◽  
Field Capacity ◽  
Regression Equations ◽  
Data Set ◽  
Water Capacity ◽  
Available Water ◽  
Available Water Capacity ◽  
Wilting Point

SummaryStatistical equations were derived for estimating three soil moisture constants, i.e. field capacity (FC), wilting point (WP) and available water capacity (AWC), from soil saturation percentage (SP), which is an easily determinable parameter. The regression equations were evaluated from a data set obtained on 438 soil samples collected from different horizons of 111 profiles of the Indogangetic Plains in northern India, having a wide variation of texture and other physico-chemical properties. The three soil moisture constants were positively correlated with logarithms of SP (r = 0·985 for FC v. In SP, 0·979 for WP v. In SP, and 0·914 for AWC v. In SP). The regression equations were thetested on an independent set of experimental data on 57 samples collected from 14 representative soil profiles of the study area. Values of the three moisture constants of this data set, predicted from the regression equations, were in exceptionally good agreement with the observed values. The mean estimation error (the error of the estimated value relative to the measured value) was only 0·55% for FC, 0·12% for WP and 0·67% for AWC.

scholarly journals Evaluation of land surface model simulations of evapotranspiration over a 12-year crop succession: impact of soil hydraulic and vegetation properties

2015 ◽  
Vol 19 (7) ◽  
pp. 3109-3131 ◽  
Author(s):  
S. Garrigues ◽  
A. Olioso ◽  
J. C. Calvet ◽  
E. Martin ◽  
S. Lafont ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Properties ◽  
Land Surface ◽  
Field Capacity ◽  
Rooting Depth ◽  
Soil Parameters ◽  
Mesophyll Conductance ◽  
Field Scale ◽  
Wilting Point ◽  
Crop Succession

Abstract. Evapotranspiration has been recognized as one of the most uncertain terms in the surface water balance simulated by land surface models. In this study, the SURFEX/ISBA-A-gs (Interaction Sol–Biosphere–Atmosphere) simulations of evapotranspiration are assessed at the field scale over a 12-year Mediterranean crop succession. The model is evaluated in its standard implementation which relies on the use of the ISBA pedotransfer estimates of the soil properties. The originality of this work consists in explicitly representing the succession of crop cycles and inter-crop bare soil periods in the simulations and assessing its impact on the dynamics of simulated and measured evapotranspiration over a long period of time. The analysis focuses on key parameters which drive the simulation of ET, namely the rooting depth, the soil moisture at saturation, the soil moisture at field capacity and the soil moisture at wilting point. A sensitivity analysis is first conducted to quantify the relative contribution of each parameter on ET simulation over 12 years. The impact of the estimation method used to retrieve the soil parameters (pedotransfer function, laboratory and field methods) on ET is then analysed. The benefit of representing the variations in time of the rooting depth and wilting point is evaluated. Finally, the propagation of uncertainties in the soil parameters on ET simulations is quantified through a Monte Carlo analysis and compared with the uncertainties triggered by the mesophyll conductance which is a key above-ground driver of the stomatal conductance. This work shows that evapotranspiration mainly results from the soil evaporation when it is continuously simulated over a Mediterranean crop succession. This results in a high sensitivity of simulated evapotranspiration to uncertainties in the soil moisture at field capacity and the soil moisture at saturation, both of which drive the simulation of soil evaporation. Field capacity was proved to be the most influencing parameter on the simulation of evapotranspiration over the crop succession. The evapotranspiration simulated with the standard surface and soil parameters of the model is largely underestimated. The deficit in cumulative evapotranspiration amounts to 24 % over 12 years. The bias in daily daytime evapotranspiration is −0.24 mm day−1. The ISBA pedotransfer estimates of the soil moisture at saturation and at wilting point are overestimated, which explains most of the evapotranspiration underestimation. The use of field capacity values retrieved from laboratory methods leads to inaccurate simulation of ET due to the lack of representativeness of the soil structure variability at the field scale. The most accurate simulation is achieved with the average values of the soil properties derived from the analysis of field measurements of soil moisture vertical profiles over each crop cycle. The representation of the variations in time of the wilting point and the maximum rooting depth over the crop succession has little impact on the simulation performances. Finally, we show that the uncertainties in the soil parameters can generate substantial uncertainties in ET simulated over 12 years (the 95 % confidence interval represents 23 % of cumulative ET over 12 years). Uncertainties in the mesophyll conductance have lower impact on ET. Measurement random errors explain a large part of the scattering between simulations and measurements at half-hourly timescale. The deficits in simulated ET reported in this work are probably larger due to likely underestimation of ET by eddy-covariance measurements. Other possible model shortcomings include the lack of representation of soil vertical heterogeneity and root profile along with inaccurate energy balance partitioning between the soil and the vegetation at low leaf area index.

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