Soil Science Commons^™

Factors Affecting Anion Movement And Retention In Four Forest Soils, D. W. Johnson, D. W. Cole, H. Van Miegroet, F. W. Horng

Watershed Sciences Faculty Publications

Three hypotheses concerning the movement and retention of anions in forest soils were tested in a series of laboratory and field studies on two Tennessee Ultisols with mixed deciduous forest cover and two Washington Inceptisols, one with deciduous (red alder Alnus rubra Bong.) and one with coniferous [Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco] forest cover. The first hypothesis, that sulfate and phosphate retention was related to adsorption to free Fe and Al oxides, which were in turn related to soil parent material and degree of weathering, was not supported by results of laboratory and field studies. The young, relatively unweathered Washington …

The Influence Of Thermo-Gradients Upon Water Movement And Retention In Unsaturated Soils, Jose V. Salazar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Temperature differences of about 5, 10, and 15 V, were applied to uniformly packed and insulated horizontal column of Millville silt loam soil using mean temperatures near 13, 14, 15, 16, 17, 18, 19, 20 and 23.5 C. The temperature distribution along the soil column was determined using copper constantan thermocouples. Soil samples were taken to determine volumetric moisture content, and soil water potential, using the vapor pressure psychometer technique. The thermodynamic flow equation of Taylor and Cary, (1964) was used to calculate the hydro-thermal transfer coefficient (ß) as given by:

-ß = d(μ_w)_T / dlnT

where …

Movement Of Atrazine In Soil Under Furrow Irrigation, Jyothi Veerabhadrappa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Movement of atrazine in response to furrow irrigations was studied using the samples of Timpanogos silt loam soil. Distribution in soil profile of surface applied herbicide was determined by drawing samples of water extracts through porous cylinders. Atrazine quantity was determined by spectrophotometer.

It was observed that the herbicide found in the water extracts was an indication of the quantity present in the soil. The herbicide moved readily with the applied water. Irreversible thermodynamic model could not be applied because of the initial and final boundary conditions. The pattern of movement was in conformity with the chromatographic theory.

Simultaneous Movement Of Water And Herbicides In Unsaturated Soils, Ming-Shyong Yang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Since weed killers were developed in the early part of the decade beginning in 1940, herbicides have been increasing in use until they are now widely used to control weeds. The application of herbicides has thus become a regular agricultural and ecological practice.

An Application Of A Thermodynamic Flow Equation To Water Movement In Unsaturated Soil, Brennan Derry Soane

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The movement of water in soil presents many interesting problems to the research worker. It is also a subject which finds wide and important application in agriculture and several branches of engineering.

The object of this work was to examine the usefulness of a new equation of flow of water in unsaturated soil. If valid, this new approach may be able to eliminate some of the gaps in our present knowledge of the subject.

All soil lying above the capillary fringe of a water table is in the unsaturated state with respect to water. This means that in any macroscopic …

Bulletin No. 139 - The Movement Of Soluble Salts With The Soil Moisture, F. S. Harris

UAES Bulletins

In irrigated districts, where excessive quantities of water are used, there is usually an accumulation of alkali salts in the soils of the lower lands. These salts are probably dissolved from the soils through which the percolating waters pass and are carried along until the water comes to the surface and is evaporated, when the salts are deposited as a crust at the surface. Many of the most fertile soils of the arid regions have been ruined by the bringing to the surface of soluble salts in such large quantities that the growth of crops is prohibited. The rapidity with …

Bulletin No. 115 - The Movement Of Water In Irrigated Soils, J. A. Widtsoe, W. W. Mclaughlin

UAES Bulletins

This bulletin embodies a part of the data secured in the irrigation investigations of this Station. It aims to contribute something to our knowledge of the movement of water in irrigated soils . The science of irrigation can not well be built until the laws involved in the mutual relationships of waters, soils and crops are understood with fair accuracy. Much has been done by numerous investigators, during the last fifty years, to give a clearer comprehension of the movement of soil moisture; but the field experiments have dealt largely with saturated soils, and the laboratory experiments have seldom taken …

Bulletin No. 114 - The Movement Of Nitric Nitrogen In Soil And Its Relation To "Nitrogen Fixation", Robert Stewart, J. E. Greaves

UAES Bulletins

In the spring of 1903, we commenced at the Utah Experiment Station a series of experiments, the purpose of which was to study the development and movement of nitrates in irrigated soil. The work was so outlined that it should give some very definite results, both as to the influence of water and the plant, upon the nitric nitrogen content of the soil.

Bulletin No. 106 - A Study Of The Production And Movement Of Nitric Nitrogen In An Irrigated Soil, Robert Stewart, J. E. Greaves

UAES Bulletins

The problem of maintaining the nitrogen content in our agricultural soils is one of vital importance to the development of a permanent system of agriculture. Any investigation, therefore, which tends to throw any light on the conditions which are necessary for maintaining the maximum supply of nitrogen in our soils needs no apology for its institution.