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Full-Text Articles in Engineering

Agrochemical Indicators Of New Irrigated Graph-Meadow Soils Formed On The Iii Underfladder Terrace Of Syrdarya, J.M. Kuziev Dec 2020

Agrochemical Indicators Of New Irrigated Graph-Meadow Soils Formed On The Iii Underfladder Terrace Of Syrdarya, J.M. Kuziev

Irrigation and Melioration

Presents material on the geographical location, geomorphological and geological structure, as well as the agrochemical state of irrigated serozem-meadow soils, common in the Mirzaabad district of the Syrdarya region. According to the data obtained on the chemical analysis of soils, the studied soils are medium- and heavily loamy in texture, where particles of coarse sand predominate (0.05-0.01%). In the arable horizon of these soils, the humus content is 1.088-1.214%, total nitrogen 0.079-0.089%, total phosphorus 0.109-0.124%, and total potassium within 1.15-1.24%, and on the basis of these data, a regularity of the underlying horizon of these soils. The degree of provision …


Comparative Analyses Of Variable And Fixed Rate Irrigation And Nitrogen Management For Maize In Different Soil Types: Part I. Impact On Soil-Water Dynamics And Crop Evapotranspiration, Vasudha Sharma, Suat Irmak Nov 2020

Comparative Analyses Of Variable And Fixed Rate Irrigation And Nitrogen Management For Maize In Different Soil Types: Part I. Impact On Soil-Water Dynamics And Crop Evapotranspiration, Vasudha Sharma, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

Understanding the soil-water dynamics and maize evapotranspiration (ETc) under variable rate irrigation (VRI) and variable rate fertigation (VRF) management with respect to soil spatial variability constitutes the basis for developing effective variable rate water and nitrogen management strategies. This long-term research was designed to quantify and compare the soil-water dynamics, including available water (AW), and ETc during vegetative and reproductive growth periods of VRI, fixed rate irrigation (FRI) and no-irrigation (NI) under fixed rate fertigation (FRF), VRF and pre-plant (PP) nitrogen management in three different soil types [Crete silt loam (S1); Hastings silty clay loam (S2) and Hastings silt loam …


Bio-Electrochemical Denitrification Systems And Applications For Nitrogen Removal In On-Site Wastewater Treatment, Kamal Ziad Taha Jun 2020

Bio-Electrochemical Denitrification Systems And Applications For Nitrogen Removal In On-Site Wastewater Treatment, Kamal Ziad Taha

USF Tampa Graduate Theses and Dissertations

Denitrification experiments using biological cathodes (biocathodes) were conducted in three separate experiments. The first experiment was to observe whether the rate of denitrification in biocathodes could be increased with added ammonium at mass (mg/L) ratios of 0.100 (2.5/25), 0.05 (1.25/25), 0.0250 (0.625/25), and 0.0125 (0.3125/25) (parts ammonium to nitrate (NH4+-N/ NO3--N). The purpose of the ammonium present was to provide the microorganisms a starting nitrogen source for assimilation to biomass which, in theory, would encourage the removal of nitrate through dissimilatory denitrification. As mixed cultures were used, ratios tested were based on simplifying future operation of scaled-up biocathodes applied to …


Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle Jan 2020

Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle

Theses and Dissertations--Civil Engineering

Fluvial sediment is well recognized as a critical factor in both carbon and nutrient budgets within stream systems. However, we find very few studies of reactivity and isotope enrichment for stream water from agricultural and urban streams and the class of substrate known as fluvial sediment organic matter. This study investigated the hypothesis that fluvial sediment is subject to degradation even though many previous studies have considered this class of substrate generally inert. Therefore we qualify that elemental and isotopic signatures of fluvial sediment organic matter should be considered potentially non-conservative when used in tracer studies. Methods applied to this …