Physical Sciences and Mathematics Commons^™

An Examination Of The Inorganic Nitrogen Status Of A Soil Of The Alaskan Coastal Tundra Plain, Norton R. Munn

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This experiment was designed to measure in situ concentrations of NH₄⁺ and NO₃^--N in a soil of the arctic coastal tundra plain, to determine if nitrification was taking place in this soil and to determine if the vascular plants growing in this soil could assimilate NH₄⁺-N.

The extractable NH₄⁺-N concentration was approximately 40 μg/g in the 0₁ horizon and 10 μg/g in the 0₂ horizon. The NO₃^--N concentration was approximately 5 μg/g in the 0¹ horizon and 4 μg/g in the 0_{2 …}

Evaluation Of The Filter Paper Method For Estimating Soil Water Potential, Samir Al-Khafaf

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The filter paper method for measuring soil water potential was evaluated. The method was calibrated using salt solutions (-1.4 bars to -22.4 bars), sample chamber psychrometer (-1 to -50 bars), pressure plate (-0.1 to -15 bars) and soil column at equilibrium (0 to -0.2 bars). It was found that the absolute temperature had little effect on the predicted soil water potential, but a temperature variation had a large effect. It was found that the temperature fluctuation must be small. The predicted water potential was influenced by the type of contact of the soil with the filter paper. It is suggested …