Soil Science Commons^™

The Effect Of Salinity Level Upon The Yield, Root Growth, And Water Extraction Of Contrasting Rooting Subpopulations Of Alfalfa (Medicago Sativa) Under Conditions Of Zero Leaching, Laura A. Vincent

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A major problem in irrigated agriculture in the Western U.S. is the gradual accumulation of salinity in the plant root zone. These nonuniformly saline soils contain increasing amounts of salinity with depth, and salt accumulation is accelerated in situations where leaching is minimized. Root growth and thus plant yield is limited in these soils due to decreased water uptake. We studied the root growth of two subpopulations of alfalfa differing in their ability to produce fibrous roots to determine if altering root morphology would increase plant yield and water extraction, in an irrigated saline soil.

Soil profiles for a control …

The Evaluation Of A Computer Model To Predict The Effects Of Salinity On Crop Growth, James K. Wolf

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A model was developed to predict the effects of soil salinity on crop growth. The model makes three major assumptions: 1) Relative yield for a growing season is directly related to the ratio of actual and potential transpiration. 2) Water uptake by plants is in response to the water potential gradient between the plant roots and the surrounding soil. 3) The effects of the soil salinity on crop growth is solely due to the affect of osmotic potential in decreasing the water potential. Minor assumptions also included are concerned with the plant growth cover, plant root growth, and the separation …

Some Aspects Of The Salinity Of Mancos Shale And Mancos Derived Soils, James C. Whitmore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Initial studies to determine the thermodynamic solubility product (K_sp) of gypsum and CaCO₃ were conducted. The influence of different electrolyte salts at different concentrations upon the solubility of gypsum and CaCO₃ was then tested. Analytical data was utilized in conjunction with a computer to calculate the activity of CaCO₃ and gypsum, the ion pair concentration and the solubility product. Indifferent salts increased the solubility of gypsum and CaCO₃, and salts with a common ion decreased the solubility of gypsum and CaCO₃.

Lithium was found to be the dominant monovalent cation present …

A Model To Predict The Effect Of Salinity On Crop Growth, Stuart W. Childs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A model is developed to predict the effects of soil salinity on crop growth. As an outgrowth and extension of the modelling efforts of Nimah and Hanks (1973a) and Gupta (1972), this model makes these principal assumptions in order to arrive at a quantitative relationship: 1) relative yield for a growing season is directly related to the ratio of actual and potential transpiration. 2) Water uptake by plants is in response to the water potential gradient between the plant at the soil surface and the soil surrounding the plant roots. 3) the effect of salinity on crop growth is solely …

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 …