The root growth of irrigated perennial pastures and its effect on soil structure.

1953 ◽  
Vol 4 (3) ◽  
pp. 283 ◽  
Author(s):  
KP Barley
Keyword(s):  
Soil Moisture ◽  
Root Growth ◽  
Soil Structure ◽  
Sandy Loam ◽  
Perennial Grass ◽  
Infiltration Rate ◽  
Matter Content ◽  
Infiltration Rates ◽  
Moisture Contents ◽  
Organic Particles

A separate of coherent organic particles obtained from soil suspensions by flotation and filtration is termed macroorganic matter. Three-year-old irrigated perennial pastures were found to have added 10 tons per acre of oven-dry macroorganic matter to a sandy loam at Deniliquin. Over half of this material hail been added to the top three inches of the soil. For any one pasture, as the macroorganic matter content of the top three inches of soil increased, infiltration rate decreased. When comparison was made at common macroorganic matter and soil moisture contents, soils under co-dominant white clover-perennial grass pastures were found to have higher infiltration rates than soils under lucerne-dominant pastures. The variability of the quantities measured is described.

An empirical model for drainage from soil under rain fed conditions

Soil Research ◽  
1977 ◽  
Vol 15 (3) ◽  
pp. 205 ◽  
Author(s):  
AR Aston ◽  
FX Dunin
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Empirical Model ◽  
Sandy Loam ◽  
Empirical Relationship ◽  
Field Conditions ◽  
Natural Field ◽  
Moisture Contents ◽  
Weighing Lysimeter

An empirical relationship was derived for drainage from a podzolic sandy loam using a weighing lysimeter at Krawarree, N.S.W. The form of the equation was similar to those used to describe drainage following irrigation. The agreement between computed and measured soil moisture contents over a period of five years was good, and indicated the usefulness of such an approach to characterize drainage of soil water under natural field conditions.

COMPACTION AND SETTLING OF QUEBEC SOILS IN RELATION TO THEIR SOIL-WATER PROPERTIES

1982 ◽  
Vol 62 (1) ◽  
pp. 165-175 ◽  
Author(s):  
C. R. DE KIMPE ◽  
M. BERNIER-CARDOU ◽  
P. JOLICOEUR
Keyword(s):  
Organic Matter ◽  
Water Retention ◽  
Sandy Loam ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Behavior ◽  
Matric Potential ◽  
Moisture Contents ◽  
Water Retention Properties ◽  
Soil Water Properties

Twenty-one topsoils, with texture varying from sandy loam to clay and organic matter content ranging from 1.6 to 11.9%, were submitted to compaction and settling at different moisture contents where dry bulk density was determined. Under compaction, the density curve went through a maximum while a minimum was observed in the case of settling. Optimum moisture contents corresponding to these two characteristic densities were almost the same. The most important physical properties affecting soil behavior under compaction and settling were found to be water retention properties at low matric potential which themselves depended primarily on organic matter content. Samples submitted to compaction had saturated hydraulic conductivities less than 1 cm/h, while after settling, Ksat measurements ranged from 0.8 to 234 cm/h. Organic matter played an important role in reducing the effects of compaction, and moisture content alone was not sufficient to predict the best conditions for workability in the fields.

scholarly journals Effects of Variable Angular Velocities and Soil Moisture Contents on Undrained Shear Strength in a Sandy Loam Soil (Eutric Leptosol)

2016 ◽  
Vol 11 (2) ◽  
pp. 49-60
Author(s):  
David Lomeling ◽  
Juma L.L. Yieb ◽  
Modi A. Lodiong ◽  
Mandlena C. Kenyi ◽  
Moti S. Kenyi ◽  
...  
Keyword(s):  
Shear Strength ◽  
Soil Moisture ◽  
Sandy Loam ◽  
Undrained Shear Strength ◽  
Sandy Loam Soil ◽  
Moisture Contents ◽  
Angular Velocities ◽  
Loam Soil ◽  
Undrained Shear

Assessment of variability of soil Infiltration Characteristics in Forage Cover

2020 ◽  
Vol 7 (03) ◽  
Author(s):  
AKRAM AHMED ◽  
A. K. PAL ◽  
V. K. PANDEY ◽  
MAHENDRA PRASAD ◽  
ASHUTOSH UPADHYAYA
Keyword(s):  
Steady State ◽  
Sandy Loam ◽  
Infiltration Rate ◽  
Panicum Maximum ◽  
Soil Infiltration ◽  
Infiltration Rates ◽  
Bare Land ◽  
Physically Based ◽  
Loam Soil ◽  
Horton Model

In India, very limited knowledge of soil infiltration characteristics in forages are available. In this study, infiltration characteristics of land covered by six forages have been studied with respect to bare land in sandy loam soil. Two empirical (Kostiakov and Horton) and two physically-based (Phillip and Green‒Ampt) models have been employed to estimate infiltration characteristics and compared with observed field infiltration data. The steady-state infiltration rates measured in forages and bare land were significantly (p less than 0.05) different. The highest average steady-state infiltration rate was measured in Panicum maximum (9.00 cm h-1) followed by TSH (7.40 cm h-1) and least was recorded in Cenchrus ciliaris (2.65 cm h-1) whereas the average steady-state infiltration rate recorded for bare land was 1.90 cm h-1. Results showed that the Kostiakov and Phillip model simulated the field infiltration characteristics with higher accuracy than the two other models except for Chrysopogonfulvus and bare land in which the Horton model outperformed other models. Higher steady-state infiltration rates in forages were attributed to more porosity measured in the soils under forages as compared to bare land.

scholarly journals Relative Infiltration Rate of Puerto Rican Soils

1969 ◽  
Vol 52 (3) ◽  
pp. 233-240 ◽  
Author(s):  
M. A. Lugo López ◽  
J. Juárez ◽  
J. A. Bonnet
Keyword(s):  
Puerto Rico ◽  
Puerto Rican ◽  
Classification System ◽  
Sandy Loam ◽  
Infiltration Rate ◽  
Department Of Agriculture ◽  
Mean Values ◽  
Infiltration Rates ◽  
The Mean ◽  
The U.S

Data are presented here on the minimum rate of infiltration (eighth-hour) of 57 main soil types of Puerto Rico. The study included a total of 740 tests. Mean infiltration rates vary from a high value of 11.49 inches of water per hour in Yunque sandy loam, to a low of 0.07 in Aguirre clay, and 0.01 in Palmas Altas and Britton clay. When the soils were arranged according to a simple, practical classification system in use in Puerto Rico the mean values ranged from 0.01 in group 5w to 7.82 inches in group 11. When the soils were grouped following the latest classification system developed by the U.S. Department of Agriculture, mean values for soils included in the order Vertisol ranged from 0.07 to 3.83 inches. Mollisols, Oxisols, and Ultisols showed the highest infiltration values. Information is hereby given as to the effects of various soil treatments on infiltration rates.

scholarly journals Evidence for enhanced infiltration of ion load during snowmelt

2010 ◽  
Vol 7 (1) ◽  
pp. 1431-1457
Author(s):  
G. Lilbæk ◽  
J. W. Pomeroy
Keyword(s):  
Soil Moisture ◽  
Infiltration Rate ◽  
Frozen Soil ◽  
Ion Concentration ◽  
Soil Conditions ◽  
Ion Concentrations ◽  
Infiltration Rates ◽  
Dry Soil ◽  
Infiltration Excess ◽  
The Impact

Abstract. Meltwater ion concentration and infiltration rate into frozen soil both decline rapidly as snowmelt progresses. Their temporal association is highly non-linear and a covariance term must be added in order to use time-averaged values of snowmelt ion concentration and infiltration rate to calculate chemical infiltration. The covariance is labelled enhanced infiltration and represents the additional ion load that infiltrates due to the timing of high meltwater concentration and infiltration rate. Previous assessment of the impact of enhanced infiltration has been theoretical; thus, experiments were carried out to examine whether enhanced infiltration can be recognized in controlled laboratory settings and to what extent its magnitude varies with soil moisture. Three experiments were carried out: dry soil conditions, unsaturated soil conditions, and saturated soil conditions. Chloride solution was added to the surface of frozen soil columns; the concentration decreased exponentially over time to simulate snow meltwater. Infiltration excess water was collected and its chloride concentration and volume determined. Ion load infiltrating the frozen soil was specified by mass conservation. Results showed that infiltrating ion load increased with decreasing soil moisture as expected; however, the impact of enhanced infiltration increased considerably with increasing soil moisture. Enhanced infiltration caused 2.5 times more ion load to infiltrate during saturated conditions than that estimated using time-averaged ion concentrations and infiltration rates alone. For unsaturated conditions, enhanced infiltration was reduced to 1.45 and for dry soils to 1.3. Reduction in infiltration excess ion load due to enhanced infiltration increased slightly (2–5%) over time, being greatest for the dry soil (45%) and least for the saturated soil (6%). The importance of timing between high ion concentrations and high infiltration rates was best illustrated in the unsaturated experiment, which showed large inter-column variation in enhanced ion infiltration due to variation in this temporal covariance.

An approach to modelling soil structure dynamics and soil structure recovery due to earthworm bioturbation and root growth

2021 ◽  
Author(s):  
Katharina Meurer ◽  
Thomas Keller ◽  
Nicholas Jarvis
Keyword(s):  
Root Growth ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Bulk Density ◽  
Size Distribution ◽  
Soil Structure ◽  
Organic Matter Content ◽  
Matter Content ◽  
Structure Evolution ◽  
Static Properties

<p>The pore structure of soil is known to be dynamic at time scales ranging from seconds (e.g. compaction) to seasons (e.g. root growth, macro-faunal activity) and even decades to centuries (e.g. changes in organic matter content). Nevertheless, soil physical and hydraulic functions are generally treated as static properties in most soil-crop models. Some models account for seasonal variations in soil properties (e.g. bulk density) due to tillage loosening and post-tillage consolidation or soil sealing. However, no model can account for longer-term changes in soil structure due to biological agents and processes. The development of such a model remains a challenge due to the enormous complexity of the interactions in the soil-plant system. Here, we present a new concept for modelling soil structure evolution impacted by biological processes such as root growth and earthworm activity. In this preliminary test of the model, we compare simulations against field observations made at the Soil Structure Observatory (SSO) in Zürich, Switzerland, that was designed to provide information on soil structure recovery following a severe compaction event. In this simple application, we modelled changes in the pore size distribution in a bare soil treatment resulting from soil ingestion and egestion by earthworms and the loosening of compacted soil by casting at the soil surface. Following calibration, the model was able to reproduce the observed temporal development of total porosity, soil bulk density and pore size distribution during a four-year period following severe traffic compaction. The modelling approach presented here appears promising and could help support the development of cost-efficient strategies for sustainable soil management and the restoration of degraded soils.</p>

A new approach to modelling soil structure dynamics and a preliminary application to structure recovery by earthworm bioturbation after heavy compaction

2020 ◽  
Author(s):  
Katharina Meurer ◽  
Thomas Keller ◽  
Nick Jarvis
Keyword(s):  
Root Growth ◽  
Pore Size Distribution ◽  
Pore Size ◽  
Bulk Density ◽  
Size Distribution ◽  
Soil Structure ◽  
Organic Matter Content ◽  
Matter Content ◽  
Structure Evolution ◽  
Static Properties

<p>The pore structure of soil is known to be dynamics at time scales ranging from seconds (e.g. compaction) to seasons (e.g. root growth, macro-faunal activity) and even decades to centuries (e.g. changes in organic matter content). Nevertheless, soil physical and hydraulic functions are generally treated as static properties in most soil-crop models. Some models account for seasonal variations in soil properties (e.g. bulk density) due to tillage loosening and post-tillage consolidation or soil sealing, but none can account for longer-term changes in soil structure due to biological agents and processes. Here, we present a new concept for modelling soil structure evolution impacted by biological processes such as root growth and earthworm activity. In this preliminary test of the model, we compare simulations against field observations made at the Soil Structure Observatory (SSO) in Zürich, Switzerland, that was designed to provide information on soil structure recovery following a severe compaction event. In this simple application, we modelled changes in the pore size distribution in a bare soil treatment resulting from soil ingestion and egestion by earthworms and the loosening of compacted soil by casting at the soil surface. Following calibration, the model was able to reproduce the observed temporal development of total porosity, soil bulk density and pore size distribution during a four-year period following severe traffic compaction. The modelling approach presented here appears promising and could help support the development of cost-efficient strategies for sustainable soil management and the restoration of degraded soils.</p>

Monitoring and prediction of soil moisture spatial–temporal variations from a hydropedological perspective: a review

Soil Research ◽  
2012 ◽  
Vol 50 (8) ◽  
pp. 625 ◽  
Author(s):  
Qing Zhu ◽  
Kaihua Liao ◽  
Yan Xu ◽  
Guishan Yang ◽  
Shaohua Wu ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Structure ◽  
Spatial Scales ◽  
Organic Matter Content ◽  
Temporal Variations ◽  
Matter Content ◽  
Soil Survey ◽  
Large Spatial Scale ◽  
Vegetation Modelling ◽  
Traditional Approaches

Accurate prediction of soil moisture spatial–temporal variations remains critical in agronomic, hydrological, pedological, and environmental studies. Traditional approaches of soil moisture monitoring and prediction have limitations of being time-consuming, labour-intensive, and costly for direct field observation; and having low spatial resolution for remote sensing, and inconsistent accuracy and reliability for landscape feature (e.g. topography, land use, vegetation) modelling. Innovative and effective approaches for accurate soil moisture simulation are needed. Pedological properties, including soil structure, particle size distribution, porosity, horizon, redox feature, and organic matter content, have been accepted as important factors controlling soil moisture and can be potentially used in soil moisture prediction. However, pedological properties mostly lack quantification (e.g. redox feature, horizon, soil structure), and soil sampling and analysis are time-consuming and costly, especially at large spatial scale. These limitations have restricted the utilisation of pedological information to predict soil moisture spatial–temporal variations at different spatial scales. To overcome these difficulties, new tools including geophysical tools and computed tomography, and new methods including mining soil survey information and integrating pedological information with landscape features and modelling, are proposed in this paper.

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