Physical Sciences and Mathematics Commons^™

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.

A Field Study Of Miscible Displacement In Saturated Soils, Lloyd Dowley Mcfadden Sadler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Extensive research has been carried out in both field and laboratory to explain water and solute movement under both saturated and unsaturated conditions. The importance of such work is obvious, since any attempt at exploring land reclamation by leaching or nutrient movement in plant feeding (to name only two) is subject to interpretations and theories of moisture flow.

Water flow through soil during reclamation by leaching can be termed miscible displacement since soil water and leaching water do not have a distinct fluid-fluid interface and will physically mix. It is probable that miscible displacement investigations can contribute to an understanding …

Salt Effect On Water Requirements Of Plants, Abdel-Wahhab M. H. Sallam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water requirement was defined by Briggs and Shantz in 1911 as the ratio of the weight of water absorbed by a plant during its growth to the weight of dry matter produced. Ballard (1933) and Williams (1935) defined water requirement as the ratio of the amount of water transpired to the amount of dry matter produced. Ballard (1933) and Williams (1935) defined water requirement as the ratio of the amount of water transpired to the amount of dry matter formed during the whole or any part of the life cycle of the plant. Miller (1938) and Kramer (1959) postulated that …

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 …