Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Entire DC Network

Assessing Phosphorus Sources With A Gis-Based Phosphorus Risk Index In A Mixed-Use, Montane Watershed, Josiah A. Johns Jun 2017

Assessing Phosphorus Sources With A Gis-Based Phosphorus Risk Index In A Mixed-Use, Montane Watershed, Josiah A. Johns

Theses and Dissertations

Elevated phosphorus (P) loading of freshwater lakes and reservoirs often results in poor water quality and negative ecological effects. Critical source areas (CSA) of P in the watershed can be difficult to identify and control. A useful concept for identification of a CSA is the P risk index (P Index) that evaluates the P risk associated with distinct source and transport pathways. The objectives of this study were to create a GIS model that adapts the Minnesota (MN) P Index for use at the watershed scale in a mixed-use, mountain environment, and to evaluate its effectiveness relative to field-based assessment. …


Effects Of Phosphorus Availability On Growth And Leaf Nutrient Concentrations In Wheat, Oat, And Cereal Rye, Jerri Lynn Dodson May 2017

Effects Of Phosphorus Availability On Growth And Leaf Nutrient Concentrations In Wheat, Oat, And Cereal Rye, Jerri Lynn Dodson

MSU Graduate Theses

Adequate soil phosphorus (P) is critical for the growth and nutrient content of forages for grazing animals. On low fertility soils, tall fescue responds to P fertilization with increased yields and improved leaf nutrient contents of P, magnesium (Mg), calcium (Ca), and potassium (K) in winter months. My objective was to examine the effect of P availability on growth and leaf nutrients in annual cereal grains commonly grown for winter forage. Soft red winter wheat (Triticum aestivum), oat (Avena sativa), and cereal rye (Secale cereale) were grown hydroponically in greenhouse conditions in complete nutrient solutions with varying P concentrations of …


Assessing Phosphorus Sources With Synoptic Sampling In The Surface Waters Of A Mixed-Use, Montane Watershed, Austin Willis Pearce May 2017

Assessing Phosphorus Sources With Synoptic Sampling In The Surface Waters Of A Mixed-Use, Montane Watershed, Austin Willis Pearce

Theses and Dissertations

Few elements in surface waters are monitored as closely as phosphorus (P) due to its role in the eutrophication and degradation of surface waters. Limiting P mobilization from source areas is, therefore, a central goal of water quality protection plans. But the work of locating sources in mixed-use watersheds is challenged by the spatial and temporal variability of critical source areas (CSAs) of P. Synoptic sampling is a proven method for capturing the spatial variation of water quality parameters in surface waters, though it's not often used to track temporal dynamics across the same study area. Phosphorus fractionation is an …


Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening Apr 2017

Nutrient Loading Reduction In A Tile Drained Agricultural Watershed Through Watershed-Scale Cover Cropping: A High Resolution Analysis, Benjamin Gerald Bruening

Theses and Dissertations

Nutrient pollution originating from agricultural regions in the Midwest is a serious issue, leading to pollution of drinking water sources as well as large hypoxic zones in the Gulf of Mexico. The source of much of this contamination has been shown to be runoff from agricultural fields in the Upper Mississippi River Basin. One method that has been shown to reduce this pollution from the Upper Mississippi River Basin is the planting of winter cover crops. Winter cover crops such as rye and tillage radish have been shown to significantly reduce nitrate exported from agricultural fields, even in tile-drained watersheds …