Soil Science Commons^™

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 …

Catalytic Effect Of Soil Components On The Nitrite Transformation In Buffer Acid Solutions, Laxman G. Kuratti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrite decomposition in buffer solutions of pH 3, 4, and 5 was observed to be a first order reaction with rate constants (k) 6.39 x 10^-3, 1.15 x 10^-3, and 0.17 x 10^-3, respectively. When 10 grams of two different soils were introduced, the reaction was catalyzed in all three pH conditions studied. This effect, however, was more pronounced in pH 5.

When 10 grams of soil were introduced, all the added nitrite was not recovered. The deficit ranged from 17 to 30 parts per million when 150 parts per million nitrite nitrogen was …

A Formula To Express Evapotranspiration As A Function Of Soil Moisture And Evaporative Demands Of The Atmosphere, Aldo L. Norero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A mathematical expression was developed and tested which describes the relation between evapotranspiration and soil moisture. A general premise of this mathematical model is that the evapotranspiration-soil moisture relationship is determined by interaction of climatic, soil and plant factors. The basic model is

dETa/dYs = -ke[1-(ET_a/ET_mx)]

in which ET_a is the actual evapotranspiration, Ψ_s is the total soil water potential, k is a proportionality coefficient, ∈ is the soil moisture extraction capacity of the atmosphere , and ET_mx is the evapotranspiration that would occur from a particular crop-soil unit when soil moisture was …