Soil Science Commons^™

Influence Of Las Vegas Wash Density Current On Nutrient Availability And Phytoplankton Growth In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

Density currents are commonly formed in reservoirs because of temperature or salinity induced density differences between inflowing and receiving waters. Anderson and Pritchard (1951) were among the first to demonstrate this in their investigations of density currents in Lake Mead. They found that the Colorado River formed an underflow in Lake Mead during the winter, an overflow in the spring and an interflow in the summer and fall. Wunderlich and Elder (1973) have since described the hydromechanics of these types of flow patterns, and density currents have been reported for several other large reservoirs (Carmack et al. 1979, Johnson and …

Bulletin 3992 - Nitrogenous Fertilisers For Cereal Production, M. G. Mason

Bulletins - 3000 - 3999

Because fertiliser prices continue to rise, it is becoming increasingly important to understand what affects the response to fertilisers by crops.

Among the many factors influencing crop response to nitrogen applications, the most important are the season, soil type, paddock history, time of application and source of nitrogen. Before deciding whether to use nitrogen on a cereal crop, which source to use and at what rate, the farmer needs some understanding of how these factors work.

Nitrogenous Fertilisers For Cereal Production, M G. Mason

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

Among the many factors influencing crop response to nitrogen applications, the most important are the season, soil type, paddock history, time of application and source of nitrogen. Before deciding whether to use nitrogen on a cereal crop, which source to use and at what rate, the farmer needs some understanding of how these factors work.

Calcium Carbonate Dissolution And Precipitation In Water: Factors Affecting The Carbonate Saturometer Method, Lyle M. Dabb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The carbonate saturometer method developed by Weyl (1961) was studied in respect to the effect of several variables on the solubility of carbonates. The solubility of three solid carbonate materials was measured in four different salt solutions, at four ionic strengths, and at two different temperatures. The solids studied included: calcite, dolomite, and a calcareous soil.

It was found that the three solid carbonate materials varied in solubility from a low in the soil carbonates to a high in dolomite.

Increasing the ionic strength of the solution increased the solubility of most of the solid carbonate materials.

By decreasing the …

Micronutrients And Biological Patterns In Lake Mead, Hasan K. Qashu, Lorne G. Everett, J. S. Carlson, Bureau Of Reclamation

Publications (WR)

Progressive increases in concentration of dissolved solids in the Colorado River water from Lake Powell to Imperial Dam seem to alter plankton dynamics and biological productivity of the river. Also, changes in biological productivity and micronutrients concentrations occur within the same reservoir. Development of a digital simulation model to predict micronutrients concentrations and biological productivity is necessary for diagnosing changes in plankton population and effluent-carrying capacity of the system. The objectives of the study are: (1) to determine trace metal balance at different locations in Lake Mead, (2) to measure biological productivity and conduct plankton population counts at each sampling …

Magnesium Ion Inhibition Of Calcium Carbonate Precipitation And Its Relation To Water Quality, John J. Hassett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The effect of Mg⁺⁺ ion on the solubility of calcium carbonate was determined using P. K. Weyls "carbonate saturometer."

The amount of calcium carbonate precipitated or dissolved was measured for five series of waters when equilibrated with solid carbonate.

It was found that the effect of Mg⁺⁺ ion on solubility depend upon the nature of the solid phase: surface area, coprecipitated Mg⁺⁺, minerology, etc.

Pure low area calcite showed an increase in solubility which could be explained by ion-pair formation, while its other carbonates departed from this behavior.

How Important Is Sulphur For Pastures?, R N. Glencross, W. J. Cox

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

With the introduction of low sulphur compound and concentrated fertilisers, a new look is required at the sulphur status of West Australian soils, and the sulphur requirement of pasture.

In this article the functions of sulphur, deficiency symptoms and potential problem soils are described.

Current recommendations and plans for future research work are outlined.

Copper, Zinc And Molybdenum Fertilizers For New Land Crops And Pastures : 1969, J W. Gartrell, R. N. Glencross

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

Four years of intensive research into soil deficiencies in developing areas have resulted in a more comprehensive understanding of the need for trace elements in Western Australia.

Experiments On The Inactivation Of Zinc By The Mineral Fractions Of The Soil, John J. Hassett

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Zinc deficiency, in many cases, is closely related to organic matter decomposition. DeRemer and Smith (1964) studied the effects of decomposing sugar beet tops on the reactions of Zn⁶⁵ in a Portneuf soil. They found that with time the Zn⁶⁵ associated with lime minerals, exchangeable, and water soluble fractions of the soil decreased, while that found with the organic and mineral fractions increased. This increase in the mineral fraction is of particular interest, since the majority of the Zn⁶⁵ was found to be with this fraction after a period of time. They also showed that the increase …

Nature Of Non-Biological Decomposition Of Nitrite In Acid Media, Mukkatira Kariappa Mahendrappa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Curiosity is the cause of investigations, and the thirst for knowledge originates from it. Many times at the end of investigations, the number of questions raised are greater than those for which answers are sought. Therefore, all the information gathered through scientific investigations may not be of value for immediate application in practical life. Nevertheless, no research can be considered less important than the other because the integration of several scientific findings considered less less important at the time of investigation may reveal something of very high significance. Similarly, the study of various transformation reactions that the added fertilizers undergo …

Water Chemistry Survey Of Boulder Basin, Lake Mead, P. R. Tramutt, Bureau Of Reclamation

Publications (WR)

The survey results indicate that the impoundment of water behind Hoover Dam has not adversely affected the dissolved oxygen (DO) content and that water quality and DO content were uniform regardless of depth. The study made in April-May 1964 will provide water quality data of Lake Mead prior to releases from Lake Powell as a basis for evaluating Lake Powell's effect on water quality and limnology of Lake Mead. The performance of a DO analyzer was tested and found unsatisfactory at depths below 150 ft. Parameters tested by standard chemical analyses of water samples in the Denver Laboratory and by …

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.

Differentiation Between The Ph Effect And The Bicarbonate Ion Effect In Causing Lime-Induced Chlorosis, Hyrum Del Var Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lime-induced chlorosis has been recognized for many years as a problem where plants are grown on calcareous soils. There are many factors associated with and influencing this form of iron chlorosis and because of this it has been very difficult to determine the relationship between the factors and chlorosis.

The Effect Of Chelates On Phosphorus Availability And Mobility, Salah Ahmed Tahoun

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil-phosphorus relations and plant-phosphorus relations have attracted the interest of many investigators since Liebig introduced his famous theory about the importance of the mineral matters to the plant in 1840. It was soon realized that phosphorus nutrition was a problem not easily solved for two reasons. 1. The added phosphorus fertilizers, soon after soil application are converted by some reactions in the soil to complex compounds far less soluble, consequently less available to the plant. Conclusions about this process led to controversial debates until it was discovered that a general statement covering all soils was impossible since the reactions involved …

Phosphorus Status Of Genola Soils In Utah, Warren E. Bendixen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

With increasing pressure on economical production of crops, more fertilizers are being applied to the soil each year to increase crop yields. Economical production of crops with applications of fertilizer requires an evaluation of the essential elements of the various crops so applications of fertilizer will not exceed the law of diminishing returns.

Because varying soil, moisture, and climatic conditions influence the response to added fertilizers, some workers (18, 26, 38) have contended that the only reliable way of determining the fertilization needs of a crop is to conduct a trial on the particular farm. The length of time involved …

The Mineral Content Of Various Sections Of Some Plants As Influenced By Conditions Associated With Lime-Induced Chlorosis, Hyrum Del Var Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The so-called "lime-induced" chlorosis has been recognized for many years as a problem where plants are grown on calcareous soils. The characteristics associated with lime-induced chlorosis are the same as those associated with iron deficiency chlorosis--interveinal yellowing of the leaves at the meristemic region combined with reduced vigor of the plant as a whole. Lime-induced chlorosis is unique in that the iron content of both chlorotic plant and the soil do not always show a deficiency in iron when chemically analyzed. This leads to the theory that iron is inactivated in both the soil and plant.

Although no single factor …

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.

Copper Minerals For Fertilizer Use, R N. Glencross

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

COPPER fertilizers have an important role in maintaining: and increasing Western Australia's agricultural production.

On many soils they are essential for cereal growing or pasture production and persistence and for animal health and wool quality.

They are also sometimes used for fruit trees, vines, and vegetables.

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 …

The Thermodynamics And Some Practical Aspects Of Zinc Adsorption On Calcite, Dolomite, And Calcian-Magnesite Minerals, Jerome J. Jurinak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Zinc is one of the essential elements required for the normal growth of plants. The total amount of zinc commonly occurring in soils is usually many times greater than that necessary to supply the needs of actively growing plants. The ability of the soil to "fix" zinc in form unavailable for plant use, however, has made the zinc deficiency disease an important plant nutrition problem in the major fruit and nut growing regions of the West. Fixation mechanisms which have been postulated as contributing to zinc deficiency include organic complexes, precipitation of insoluble inorganic salts, and strong zinc-clay intersections. It …