Physical Sciences and Mathematics Commons^™

Sorption Temperature And And The Stability Of Iron-Bound Soil Organic Matter, Michael L. Nguyen

Doctoral Dissertations

The preservation of soil organic matter (SOM) is an important control on the global cycling of carbon. Long-term preservation of SOM has important implications on soil fertility and climate regulation. Minerals, such as iron oxides, can react with SOM and serve as a preservation mechanism for SOM. Globally, iron oxide-SOM interactions form a “rusty carbon sink” which protects up to 22% of organic carbon in marine sediments. Climate changes, such as warming, may alter the size or efficacy of the “rusty carbon sink.” The effects of temperature, SOM composition, and mineral particle size on the formation and stability of iron …

The Effect Of Warming And Simulated Rainfall On Soil Microbial Community Structure And Function, Torri A. Ivancic

Biology Theses

Soil respiration, from plant roots and soil microbes, accounts for 60 – 80 percent of total ecosystem respiration, with the microbial component contributing approximately 54 percent. Global climate trends resulting from CO₂ emissions include increased soil temperatures and changes in precipitation regimes resulting in less frequent, more intense rainfall events. Soil temperature and moisture availability drive soil respiration rates, but how they impact the microbial respiration is poorly qualified. I investigated how the soil microbial community responds to changes in temperature and moisture availability in a laboratory based experiment. Soils from a mixed hardwood forest under two thermal regimes …

Effects Of Temperature On Moisture Conductivity In Unsaturated Soil, Richard O'Bannon Meeuwig

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water moves in soil in response to potential gradients. The basic equation for this movement is the generalized v=-K▽Φ in which v is volume of water passing through a unit area in unit time, K is the conductivity coefficient, ▽, is the gradient operator (vector), and ▽Φ is the potential gradient.

Temperature Dependence Of Soil-Moisture Potential, Jacob Willem Kijne

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Teachers have noticed that children draw only those objects which they know by name. Doubtless the adult has a similar tendency, exemplified by the researcher, to limit his observations or to relate them to that which can be expressed in the terminology of an existing or newly developed theory. In this thesis the data obtained from studies of the temperature and pressure dependence of the relative vapor pressure over moist soil samples are analyzed by a thermodynamic approach. Not all of the results can be explained completely by means of this tool. Natural systems, such as a moist soil, are …

Relations Between Transpiration, Leaf Temperatures, And Some Environmental Factors, Ronald Kay Tew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Transpiration is the loss of water in vapor form from a plant. This is essentially the same process as evaporation except that it is modified by plant structure. Large quantities of water are removed from the soil, transferred through the conducting tissues of the plant, and dissipated into the air each day. As soon as the water is lost to the atmosphere, it becomes unavailable for human use.

The Influence Of Temperature On The Impedance To Water Flow Through Plants, Royal Duane Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This era has been termed the atomic or space age. The greatest concern of most people seems to be centered around survival from the destruction and suffering that might be caused by atomic and nuclear weapons. However, along with this, the world is confronted with perhaps a greater disaster--a potential calamity seldom realized by most people, yet a problem which grows more serious in the world each year--a tragedy which would probably be worse than destruction from nuclear weapons. This encroaching catastrophe is starvation.

Even today the majority of the people in the world do not have enough food. Each …

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 Effect Of Temperature And Moisture On Nitrification Of Applied Ammoniacal Fertilizer In A Noncalcareous Soil, Merwin Allen Stevens

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The importance of nitrogen in world agriculture has been known for many years. But in the past few decades the enormity of the problem of nitrogen economy has been recognized. Along with the recognition of this problem there has developed a great increase in the use of nitrogen fertilizers. Coupled with the increased use of nitrogen there has come about an increasing awareness of the problem involved in the use of nitrogen fertilizers.

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 …

The Effect Of Light, Soil Temperature, And Soil Moisture On High-Lime Chlorosis, Lauren M. Burtch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Chlorosis of plants from a lack of available iron is one of the most common plant nutrient problems of the calcareous soils of the west. The disease is characterized by a yellowing of the plant leaves and is accompanied, in severe cases, by a partial root death and premature defoliation (3). In addition to reducing growth, the disease greatly reduces the quality and yield of plants.

Many types of plants are affected by iron chlorosis. In Hawaii and Porto Rico rice, sugar cane and pineapple are susceptible, while in California and Arizona, citrus trees are seriously affected. In Utah apples, …