Document Type

Thesis - Open Access

Award Date

2016

Degree Name

Master of Science (MS)

Department / School

Agronomy, Horticulture, and Plant Science

First Advisor

Sandeep Kumar

Abstract

The extreme winter conditions prevailing in the state of South Dakota make it difficult for the livestock producers to manage the manure generated at the farm. The South Dakota Department of Environmental and Natural Resources does not recommend manure application in the state during the winter months when the ground is frozen. Thus, producers are left with the options such as storing the manure over a longer period until summer or spreading on snow or frozen ground. Storing manure for longer duration leads to increased risks of concentrated spills into the streams. Thus, it is important to develop management strategies for manure to reduce negative impacts to the environment. The present study was conducted to test the hypothesis that manure spread near the outlets of the watersheds would lead to an increased loss of nutrients as compared to the manure spread away from the watershed outlets. A paired watershed study was established near Colman, South Dakota, in which two watersheds were used as treatment watersheds while one was used as control. The watersheds were named as north (NW), south (SW) and east (CW) watersheds; north and south were treatment watersheds while east was the control. The North watershed received manure application on 50% area close to its outlet while south watershed received manure 50% of its area away from its outlet. At the East watershed and the areas in the north and south watershed that did not receive any manure, inorganic fertilizer was applied to meet the nutrient needs for the crop growth. Surface runoff was measured from the three watersheds, and runoff samples were collected from 2013 to 2015 to assess the impacts of manure application on water quantity and quality. Soil samples were also extracted from the three watersheds to measure the physical and chemical properties as impacted by the manure treatment. In addition, soil erosion was estimated using the Revised Universal Soil Loss Equation 2 (RUSLE2) model. Results from this study showed that soil quality, organic matter and water infiltration improved in the landscape positions that received the manure application. Manure improved the infiltration capacity of the soil and also improved the nutrient status of the soil. Runoff data did not show any particular trend among the three watersheds, rather, it varied according to the precipitation pattern and the topography of the watershed. The runoff depth was not statistically significant across the three watersheds. The north watershed showed the highest loss of nutrients into the streams while the south watershed showed the lowest. The east watershed also showed high nutrient losses which may be due to high solubility of the inorganic fertilizers. Soil erosion results showed that topography (LS factor in RUSLE) played the most important role in determining the soil erosion. Our soil erosion estimation results were coherent with the results obtained for the total suspended solids. Thus, it can be concluded that manure treatment in the south watershed showed best results in terms of reduced water quality impairment and soil erosion as nutrient concentrations in the surface runoff samples were significantly higher from the NW as compared to the other watersheds. Results from this study would provide an insight to the producers about managing manure during winter months. In addition, monitoring water quantity and quality for longer duration is strongly encouraged to assess the impacts of manure on soils and water.

Library of Congress Subject Headings

Farm manure -- South Dakota -- Management.

Agricultural wastes -- Environmental aspects -- South Dakota.

Water quality.

Soils -- Quality.

Runoff -- Environmental aspects.

Watersheds -- South Dakota.

Description

Includes bibliographical references

Format

application/pdf

Number of Pages

139

Publisher

South Dakota State University

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Rights Statement

In Copyright