Seasonal dynamics of soil-water pressure in a cracking clay soil
Clay ; England ; Model ; Oxfordshire ; Precipitation ; Seasonal variation ; Soil ; Soil properties ; Soilwater ; United Kingdom
This paper describes the results of an investigation of changes in soilwater pressure head and its relationship to the macropore network in a cracking clay soil at Brimstone Farm, Oxfordshire, UK.
Agriculture ; China ; Groundwater ; Irrigation ; Northern China ; Water ; Water budget ; Water management ; Water resources
Based on the analyses of water interactions and water balance, this paper discusses the issues on the assessment and regulation of soilwater resources, which lays the scientific basis for limited irrigation and water-saving agriculture.
The supply of water by the soil to meet the transpirational demand of crops, has been modelled on the assumption that water supply is directly related to soilwater potential. Results of field testing and discussion.
Regulation of the soilwater regime under furrow irrigation
Agropedology ; Arid lands ; Irrigation ; Mathematical model ; Methodology ; Soil ; Soil moisture;Soilwater ; Water balance ; Water cycle;Water circulation
An experimental computational method is proposed for determining the irrigation regime of agricultural crops and losses of irrigation water by infiltration beyond the root zone of the soil, based on information on soil moisture suction or soil
. A relationship is proposed approximating the curve of soilwater intake. Results of calculations of the irrigation regime of cotton by the proposed method showed that the irrigation rate and the rate of infiltration of irrigation water decrease as the soils
wetness. It was established that under furrow irrigation the soil immediately below furrows is wetted approximately to maximum moisture capacity, while in the furrow spacing the moisture content of the soil usually does not exceed field capacity
become finer in texture and the water table rises.
Soil compaction and water uptake of plants in Impact of water and external forces on soil structure. Selected papers of the 1st Workshop on soilphysics and soilmechanics, Hannover 1986.
This paper describes a method for studying the influence of soil compaction and soil structure on the water uptake of plants under controlled conditions.
Mineral soil surface crusts and wind and water erosion
Soil surface characteristics : dynamics and impact on soil erosion. Special issue
Agricultural practice ; Duricrust ; Land use ; Mineralogy ; Soil ; Soil erosion ; Soil moisture ; Soil properties ; Water erosion ; Wind erosion
The AA. briefly review how permanent and time-dependent soil properties influence surface seals and crusts and how these affect soil erosion by wind and water. They conclude with some comments on strategies for management of soil surface conditions.
The influence of soil interstitial waters on the physicochemistry of major, minor and trace metals in stream waters of the Green Lakes valley, Front Range, Colorado
Colorado ; Ecosystem ; Human impact ; Hydrochemistry ; Hydrology ; Mountain ; Soil erosion ; Soil properties ; Trace-element ; United States ; Water quality ; Watershed
The objective of this research is to study the physicochemical characteristics of major, minor and trace metals in soil interstitial and stream waters across an alpine watershed, with special emphasis on potentially geochemical reactive areas
, and to assess the influence of soil interstitial waters on stream water quality.
Modeling daily soilwater dynamics during vertical drainage using the incoming flow concept
Belgium ; Comparative study ; Cultivated land ; Drainage ; Georgia (USA) ; Model ; Soil ; Soilwater ; United States of America ; Water balance
The aim of this study was to develop a quasi-analytic model to calculate the daily soilwater dynamics during vertical drainage with reasonable accuracy for diverse soils, i.e., light, medium and heavy soils using the incoming flow concept. Three
models for the simulation of vertical drainage in soils are compared : RMSD, SRVDM and Hydrus-1D. They are tested using data of a Eutric Regosol in Bekkevoort, Belgium and a sandy soil in Georgia, U.S.
In this paper, soil erodibility in water and wind erosion research is discussed on analyzing the concept and mechanism of soil erodibility, methods to measure and calculate soil erodibility. At the same time, the defect and researching orientations
of soil erodibility in water and wind erosion are also discussed.
Effect of soil moisture on the interrelation between the rate of movement of soilwater under the effect of the temperature gradient and the concentration of the soil solution
The variation in water content of grass-covered peaty clay and clayey peat soils was studied at 6 sites in the Netherlands. The topsoils were water repellent during dry spells. However, the measurements revealed that preferential flow
was not limited to macropore flow: irregular, fingerlike wetting patterns were also formed in the soil matrix. Due to these typical wetting patterns, soilwater content varied over short distances at all sites at all sampling dates.
[b1] DLO Winand Staring Centre for Integrated Land, Soil and Water Research, Wageningen, Pays-Bas
Soil erosion and soil structure in Impact of water and external forces on soil structure. Selected papers of the 1st Workshop on soilphysics and soilmechanics, Hannover 1986.
Recent studies show that measured soil losses due to water erosion differ significantly from estimated values using nomographs derived from loess soils. Under identical environmental conditions these deviations seem to be caused by the parent
material affecting soil structure. The final questions show that research on the interaction between soil loss and soil structure needs to be forced.
In this paper the solution profiles of an eluviated loamy soil and a podzolized sandy soil are presented, and the soil formation processes as reflected in the soil solutions are related to the models proposed by Ugolini.
Part of the relationship between positive pore water pressures and hydraulic conductivity in peat soils may be explained by accumulations of methane bubbles. The AA. show how compression and expansion of gas bubbles with changes in pore water
pressure could cause changes in hydraulic conductivity and thus help to explain some observations of dependency of hydraulic conductivity in peats on pore water pressure. Consideration is also given to the effect on hydraulic conductivities of methane gas
going into solution with increase in pore water pressure.
On using the effective contact angle and the water drop penetration time for classification of water repellency in dune soils
Water repellency is commonly measured in one of two ways : by determining the contact angle between the water drop and the soil surface, and by counting the number of seconds it takes the water drop to penetrate into the soil. The purpose
of this study is to investigate which of the two tests is more suitable for measuring water repellency in dune soils.
Water table depths and color patterns in soils developed from red parent materials in Michigan, USA
Humid environment ; Land use ; Michigan ; Mineralogy ; Soil classification ; Soil properties ; Soil science ; Soilwater ; United States
Relationships between soil color patterns and depth and duration of water tables were studied using piezometers in three soil hydrosequences that had developed from different colored parent materials. Insufficient low chroma colors was the primary
reason for misclassification of soils developed from red parent materials and is thought to be related to the presence of hematite.
A study was carried out on a structured soil in the south-east of Ireland to investigate flow patterns of water in soil. The results provided preliminary evidence for preferential flow in the soil. Nitrate leaching data, from a grazing study, tended
is discussed. Soils having physical characteristics conducive to preferential flow are illustrated.
From soil and water conservation to sustainable land management
Agricultural practice ; Environment ; Environmental management ; Land use ; Soil ; Soil conservation ; Soil erosion ; Sustainable development ; Water
Part III of this volume II with 6 chapters : sustainable land use management - policies, strategies and economics; institutional and planning aspects of soil and water conservation; approaches to soil and water conservation and watershed development
; technologies for soil and water conservation and sustainable land management; adoption of soil and water conservation practices; land tenure and soil and water conservation.
This paper reports on a comprehensive investigation into crater formation in soil, sand, pastes of various simple chemicals and water targets by free-falling water drops of different sizes, heights of fall and fall velocities. This study offers
a new approach to rain erosion research in which the behaviour of the raindrop and soil surface as the 2 colliding bodies is considered.
This paper investigates the performance of selected soil and water conservation measures in the highlands of Ethiopia and Eritrea, namely Fanya Juu, soil/stone bund, grass strips and double ditches. The impact of these techniques on runoff, soil