Earth Sciences Commons^™

The Effect Of Alternate Wetting And Drying On The Ammonium And Nitrite Nitrogen Transformation In Soils, Virupax C. Baligar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Investigations were carried out to study the effect of alternate wetting and drying cycles on the mineralization, nitrification, and denitrification of soil nitrogen in two soils, in the presence or absence of added ammonium and nitrite. Soils were analyzed at the end of each drying cycle for total inorganic nitrogen, ammonium, and nitrite nitrogen. Gaseous products, i.e., ammonia, and the oxides of nitrogen (NO and NO₂) were collected in the course of drying for determination.

The drying cycles accelerated the rate of nitrogen mineralization in both soils and further increased the oxidation of applied and available ammonium. The …

Relationship Of The Soil Water Content And Microclimate To The Plant Growth Water Use Relationship Of Several Plants, Philip Dean Sandberg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Studies involving field plots, lysimeters, and garbage can lysimeters showed that an intermediate soil water level produced the most growth for a given amount of water use by oats, corn, and barley. For crested wheatgrass the lowest water level produced the most growth per water used. Field plots which were covered with sheet metal between the rows produced more plant growth per water used than the uncovered plots for the crops used in this study. One year's data were obtained on the effect of positioning the garbage can lysimeters. One half of the cans were placed on the soil surface …

A Comparative Study Of Boron Adsorption By A Calcareous And An Acid Soil, Namik M. Ali Rashid

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The adsorption of boron by Aiken clay loam and Vernal sandy loam was studied in the boron equilibrium concentration range of 0 to 40 ppm. Adsorption data were obtained at 11, 20 and 30°C. The data were analyzed by the application of the Langmuir adsorption isotherm. It was concluded that, in both soils, the adsorption of boron occurred on three distinct sites or regions.

The acid ferrigenous Aiken soil had a higher adsorption capacity for boron than the calcareous Vernal soil when compared on a unit mass basis. On the unit area basis, however, the Vernal soil adsorbed more boron …

Role Of Transition Metals In Nitrite Decomposition In Soil, J. S. Bajwa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Iron and copper increased the decomposition of nitrite significantly during the first two hours of reaction when 150 parts per million (ppm) of nitrite and nitrogen was added to an acidic soil. Manganese was found to have a slight effect. There was no additional effect of the added metals after two hours reaction time.

The higher concentration of metals was not effective in catalyzing the decomposition of the added nitrite in nitrogen. All the added nitrite nitrogen was not recovered and the deficit could be due to the formation of nitrogen gas.

Cation Exchange And Transport In Soil Columns Undergoing Miscible Displacement, Sung-Ho Lai

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical model was developed to predict the exchange of one cation by another in a soil column undergoing one dimensional cation solution displacement under steady state flow conditions. The model allowed prediction of both the solution and exchanger phase concentration of the cation in question.

The model consists of a material balance equation which is a parabolic type partial differential equation. The assumption was made that equilibrium was reached instantaneously between the cations in the solution phase and the exchanger phase. This assumption reduced the material balance equation to a form that allowed numerical solution providing the data concerning …

Salinity And Water Potential Sensor For Evaluation Of Soil Water Quality, Melvin Dee Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objective of this study was to evaluate response times of a salinity sensor and a soil psychrometer. Influences of pressure, temperature and molar concentration changes were to be measured.

Salinity sensor response times ranged from 50 to 130 minutes during solution adsorption while desorption response times were perhaps ten times as long. Temperature affected both response times and equilibrium values, but pressure did not affect either.

Soil psychrometer response times ranged from from 40 to 80 minutes for either adsorption or desorption of solution. However, other factors probably related to indirectness of measurement made the soil psychrometer fail to …

Nebraska Soil Association Map, 1969, Conservation And Survey Division

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

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.

The Course Or Behavior Of Applied Zinc To Soil Containing Different Levels Of Freshly Applied Organic Matter, Artnel Samuel Henry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic matter consists of a heterogenous mixture of plant, animal, and microbial material in various stages of decomposition. It possesses characteristics which at present are not very well known. Careful studies have been directed towards the behavior of organic matter as it affects plants directly and man indirectly. Consequently, much tire is devoted to its study from the point of metal inactivation and chelation, the earlier investigations failed to produce results worthy of the efforts expended, so a loss of interest in the continued pursuit of knowledge resulted, about two decades ago when it was learned that many polyvalent …

The Influence Of Soil Moisture Regimes And Atmospheric Environments On Transpiration And The Energy Status Of Water In Plants, Sampatrao A. Gavande

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Plant responses to different soil moisture regimes have been extensively studied. Because of interactions between the soil, plant and climatic factors, few convincing generalizations concerning the influence of soil water on the transpiration of water by plants have been established. Generally single factors or at most the interaction of two have been studied at any one time. Useful theories describing the conditions of water retention in plant tissues and movement of water through plants have been proposed. Equally useful theories have been suggested for describing the retention and transmission of water in soil. The integration of these theories and their …

Pressure Dependence Of Soil Water Matric Potential, Bozorg Bahrani

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The partial specific Gibbs¹ free energy or the chemical potential has been shown to be the most desirable thermodynamic function for describing soil-water systems. The absolute value of the chemical potential of soil water cannot be determined. If pure water at standard temperature and pressure is taken as the reference, the difference between the chemical potential of soil water and that of the reference can be measured and is called "soil water potential," which has the dimension of energy per unit mass.

The barometric pressure at the sea level has been accepted as the standard reference pressure. Thus, any …

Nitrite Reactions In Soil, John Otto Reuss

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Losses of soil nitrogen that cannot be attributed to leaching or crop removal have been observed in many field experiments. Several mechanisms have been proposed to account for these losses.

The Influence Of Advective Energy On Evapotranspiration, Mahmoud Abdel Aziz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Evaporation and transpiration from the soil and plant, respectively, have received increasing attention from those who work with water supply, irrigation, and drainage.

A Soil And Vegetation Inventory And Analysis Of Three Nebraska Sandhills Range Sites, Donald F. Burzlaff

Nebraska Agricultural Experiment Station: Historical Research Bulletins

This study was undertaken to inventory the soils and vegetation of certain areas of the Sandhills and to seek edaphic characteristics that may be the limiting factor in the distribution of various plant species. Information of this nature will permit formulation of more accurate management practices because of a refinement in delineation of range sites.

Molybdenum Deficiency On Lighter Soils, Edgar Noel Fitzpatrick

Journal of the Department of Agriculture, Western Australia, Series 4

WIDESPREAD occurrences of molybdenum deficiency of subterranean clover have been observed on sandy and gfravelly surfaced soils in recent years, and present indications are that molybdenum will join copper and zinc as a major trace element deficiency of many of these soils.

The Effect Of Moisture And Temperature On Transformation Of Applied Ammonium Sulfate In Several Western Soils, Lloyd Richard Hossner

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The conversion of ammonia nitrogen to nitrite and nitrate forms of nitrogen has aroused much attention in the past and continues to receive much of the energy of the present day researcher.

The Influence Of Soil Compaction Upon The Thermodynamics Of Soil Moisture, James E. Box Jr.

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The retention of water in soils is a very interesting subject. Soil-water research presents a great challenge to research workers. The challenge is broad in scope and extends from the field problems of large irrigation projects to the atomic scale of the solid-liquid interface.

If scientists are going to describe scientifically soil-water relations, they must ultimately utilize the instruments of science and the language of mathematics. To the end of the latter the mathematics of thermodynamics has been applied in these studies of water retention in soils.

Moisture And Temperature Effects On The Transformations Of Nitrogen From Applied Ammonium Sulfate In A Calcareous Soil, John Keith Justice

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrogen has commonly been a deficient element in the cultivated soils of the world since the beginning of agriculture. The general acceptance of the practice of using manures as a means of increasing plant growth, as shown by the records of ancient civilizations, attest to this fact. Since the time of von Liebig there has been an increasing awareness of the importance of this deficiency in soils. As a result of a better understanding of the problem and the increasing availability of commercial forms of nitrogen, a rapid increase in the use of nitrogen fertilizers has taken place in the …

A Manometric Method For The Determination Of Soil Carbonates In The Field, N. A. Polyzopoulos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In soil survey work the method now generally used to evaluate the carbonate content of the soil in the field is to observe the amount of effervescence that takes place when the soil reacts with dilute acid. The four degrees of effervescence usually recognized are designated by the symbols eo, e, es, ev and correspond roughly to a lime content of 0-0.5, 0.5-3, 3-15, and above 15 per cent, respectively. This, or course, is a very rough estimate and therefore a method is needed for the quantitative determination of carbonates in the field with a fair degree of accuracy. If …

Horizontal Movement Of Moisture In Soil, D. W. L. Read

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The movement of water in soils is of great importance to all of us but especially to agriculturalists. If it were not for this movement plants would not be able to survive in soil. If the moisture moves too freely in the soil insufficient water can be stored to supply plants during dry periods. The movement of water through soil may remove plant nutrients or accumulate salts in soil horizons.

The flow of water in soil has been studied extensively for many years. Water movement can occur in either saturated or unsaturated soil. Darcy's law can be used with a …

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 …

Soil Additives And Their Effect On The Yield Of Various Crops And The Physical Properties Of An Agricultural Soil, Gaylen L. Ashcroft

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

It is generally accepted that soil structure is very important in keeping productivity at a high level. When soils are loose and friable, mechanical impedance to root growth and seedling emergence is greatly reduced. Such soils infiltrate greater quantities of precipitation, are better aerated, and possess a more favorable temperature than puddled soils. Essential plant nutrients are also more easily available in well aggregated soil.

In the last few years, several synthetic soil additives have been placed on the market. Extravagant claims have been made about the ability of these amendments to maintain soil structure, without a sound body of …

Occurrence Of Great Soil Groups In Nebraska, J. A. Elder

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

The Regeneration And Maintenance Of Wimmera Ryegrass Pastures Under Saline Soil Condition, F L. Shier

Journal of the Department of Agriculture, Western Australia, Series 3

Over the past ten years, Wimmera ryegrass pastures at the Salmon Gums Re- VJ search Station have been improved and maintained by periodic cultivation of the soil even without applications of superphosphate. On heavy crab-holey soil affected by high salt content and unsatisfactory for wheat growing, cultivation treatments have produced remarkably uniform stands of Wimmera ryegrass as shown in the accompanying pictures. The bare patches due to salt, have been largely eliminated. If the interval between cultivations is more than three years Wimmera pastures deteriorate badly.

Water Erosion Control, L C. Lightfoot

Journal of the Department of Agriculture, Western Australia, Series 3

Although soil erosion caused by water action is common in our agricultural areas, effective erosion control measures, likely to pay for themselves quickly, can be applied in nearly every case. Plant cover above the soil surface, and fertile soil with good structures are the main factors which enable soils to resist erosion. Dense pasture gives the best cover and at the same time improves the fertility and structure of the soil both effectively and economically, so land management adjusted to the need and capability of soils, slopes and climate is of first importance. Contour practices are of secondary value and …

Kimberley Soils Need Phosphates, W. M. Nunn

Journal of the Department of Agriculture, Western Australia, Series 3

Research work carried out at the Kimberley Research Station on the Ord River, and on experimental plots throughout the East and West Kimberleys, indicates that the soils of the Kimberleys are quite as deficient in phosphorus as are the soils of our agricultural areas where superphosphate is essential to the growth of most crops.

This may come as a surprise to many people, for there has been a widespread tendency to assume that the Kimberleys soils, especially those of the Ord and Fitzroy valleys, are highly fertile.

The black earths of Queensland's Darling Downs produce most enviable yields of sorghum …

The Freezing Point Of Water In Puddled And Unpuddled Soils At Different Soil Moisture Tension Values, Robert B. Campbell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A technique that will adequately describe the physical condition of water in the soil has long been desired by scientists. The method should include the effect of soluble materials on the osmotic pressure of the soil solution, and also the effect of surface force action between the soil and soil water.

Parker (8) demonstrated that the freezing point was reduced in the presence of finely divided material. This suggested the possibility of using the cryoscopic procedure to measure the physical condition of water soil. More recently, the introduction of Thermistors for accurate temperature measurement have made it desirable to investigate …

Generalized Soil Map Of Nebraska

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

The Potash Status Of Utah Soils, Sukhendu Bikas Chaudhuri

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Potassium is one of the essential plant nutrient elements. It is used by plants in the synthesis and distribution of carbohydrates (25)² and in the formation of proteins and oils. Potassium also seems to exert many of its effects by influencing enzymatic activity in cells.

Potassium occurs as the monovalent cation on plant cells and undoubtedly exerts important effects upon such phnomona as the permiability of the cytoplasmic membranes and hydration of protoplasma. Plants assimilate potassium either from the soil solution or directly from the exchange complex.