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Management Of Microbial Nitrate Production In Agricultural Soils, Wei Shi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nitrate (NO₃^-) is of central importance in the internal soil nitrogen (N) cycle. While animal wastes and nitrification inhibitors have been used in modern agriculture for decades, their effects on soil NO₃^- concentrations in relation to microbial NO₃^- production have not been well characterized. The objective of this research was to determine microbial NO₃^- production in relation to ammonium (NH₄⁺) availability and nitrifier population activity in agricultural soils receiving animal wastes or nitrification inhibitors.

Several laboratory and field studies assessed the impacts of variously treated dairy wastes and …

Ammonium And Nitrate Effects On Growth, Development And Nutrient Uptake Of Hydroponic Wheat, Thomas M. Hooten

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The long-term effects of low and high NH₄⁺/ NO₃^- uptake ratios in a system with rigorous control of pH and nitrogen concentration are poorly understood. In two replicate studies, two cultivars of wheat (Triticum aestivum) were grown to maturity with three NH₄⁺/ NO₃^- ratios in hydroponic solution: 0/100, 25/75, and 85/15%. Nitrogen was controlled at ample levels throughout the 70-d life cycle and pH was controlled at 5.8 ± 0.2. An equimolar ratio of NH₄⁺ to Cl^- was used to facilitate charge balance. Nitrogen consumption …