Browsing by Subject "Nutrient"

Now showing 1 - 3 of 3
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    Fertilizer Guidelines for Agronomic Crops in Minnesota
    (University of Minnesota Extension, 2023-07-27) Kaiser, Daniel E
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    U.S. agricultural phosphorus partial nutrient balances and temporal nutrient use trends within Minnesota.
    (2011-12) Yee, Scott W.
    The intensity of phosphorus use in United States food production systems has raised concerns about the use-efficiency of this non-renewable resource. Past research modeling the material flows of phosphorus has found that approximately one quarter of all phosphorus losses occur within the crop cultivation phase of phosphorus’s life cycle. Imbalanced phosphorus inputs and output can result in accumulations of phosphorus within the soil environment and possible phosphorus flows out of cropland. Improvements in phosphorus management are important because excess phosphorus input into the environment can drive hypoxia and cause eutrophication in freshwater, marine, and estuary aquatic ecosystems. The research being conducted in this study builds upon previous material flow analysis (MFA) research and quantifies the partial nutrient balance of phosphorus. Research conducted in this study uses nutrient use efficiency metrics to quantify the ratio of nutrient applied and crop biomass removal. Calculations of phosphorus partial nutrient balances measure system nutrient use sustainability, specifically by calculating the ratio of biomass removal to nutrient input application. Partial nutrient balances were calculated for 1997 within 48 states and within 84 Minnesota counties in 1987, 1992, and 1997. Research conducted in this study has found that phosphorus inputs at the state and county level exceed annual crop harvest, except for a few instances when nutrient removal exceeds inputs. The temporal analysis of partial nutrient balance change has determined that the balance of phosphorus removal and input has improved from 1987 to 1997. These results show that soil fertility, crop uptake, and nutrient application vary and agricultural land management may be improved to better balance crop removal with nutrient inputs.
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    Water Quality Benefits of a MN Floodwater Storage Impoundment
    (2017-09) Guzner, Mariya
    Nutrient and sediment pollution in Lake Winnipeg and its watershed, the Red River Basin, MN, are degrading water quality and impairing aquatic health, fishability, swimmability and recreational potential. It is necessary to capture and store the pollutants phosphorus (P), nitrogen (N), and total suspended solids (TSS) on the landscape, to improve water quality and protect valuable water resources in the region. Floodwater storage impoundments have the potential to effectively capture and store nutrient pollutants and suspended sediments, and consequently improve downstream water quality. There are already several dozen similar impoundments in the state, and plans to build approximately 200 in total. The water quality benefits of a floodwater storage impoundment in the Red River Basin were tested through various methods in this study. Nutrient budgets were built for the impoundment in 2014, 2015, and 2016. Load and concentration reductions were calculated for water entering and leaving the system, for nitrogen, phosphorus, and total suspended solids. In 2016, nitrogen and phosphorus reductions of 73% and 66%, respectively, were achieved. A hypothetical load reduction calculation was also modeled to determine the effects of impoundment water release speed on pollutant capture. The soil phosphorus storage potential of the impoundment was determined through a laboratory sorption experiment. Soils at the site were analyzed for their linear adsorption coefficient (K) and equilibrium P concentration at zero-sorption (EPC0). Analysis compared soils under various land uses, including: cropped, planted with native vegetation, and flooded. Results suggest that all soils within the impoundment outperform soils at the exterior of the structure regarding phosphorus storage and buffering potential. Variation in soil-phosphorus sorption properties between sites with different vegetation types will advise cropping and planting plans to optimize water quality benefits. Results of this research are intended to advise management of the study site, similar impoundments, and constructed wetlands for water quality treatment.