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Slurry injection to optimize nutrient use efficiency in maize: Soil nitrogen dynamics and plant nutrient status / Gülle-Depotapplikation zur Optimierung der Nährstoffnutzungseffizienz im Maisanbau: Bodenstickstoffdynamik und PflanzennährstoffstatusWesterschulte, Matthias 01 September 2017 (has links)
Maize is the dominant crop in northwestern Germany and is mostly cultivated on sandy soils. Additionally, due to intensive livestock husbandry and biogas production, large amounts of liquid manures are produced. The current farm practice leads to high N and P surpluses at field level accompanied by environmental pollution, like nitrate leaching, eutrophication of non-agricultural ecosystems, and N2O emissions. The accruing liquid manures are often used for maize fertilization. Thereby, slurries are mainly broadcast applied using trailing hose applicators followed by incorporation into the topsoil. In addition, a mineral N P starter fertilizer (MSF) is band-applied below the seed-corn at planting to overcome the limited nutrient availability during the early growth stages. Using a slurry injection technique below the maize row before planting might serve a substitute for MSF. Addition of a nitrification inhibitor (NI) into the slurry before injection seems to be an option to further decrease N losses. The objectives of this thesis were to compare the current and novel fertilizing strategies with a special focus on soil mineral nitrogen (SMN) dynamics and plant P, zinc (Zn) and manganese (Mn) status. For both issues the effect of adding a NI into the slurry was investigated.
To characterize the SMN dynamics after slurry injection an appropriate soil sampling strategy had to be developed. Therefore, three consecutive field trials were conducted. The first testing of the new soil sampling approach was implemented in an existing experiment where the slurry was injected at a depth of 12 cm (upper rim) below the soil surface. The soil profile (75 cm wide) centered below the maize row was sampled using a grid-like approach to a depth of 90 cm. Around the injection zone, soil monoliths (SM) were sampled using a purpose-built soil shovel. Below the SMs and in the interrow space (15 and 30 cm distance to the row) a standardized auger procedure was used. The second experiment aimed to improve the sampling strategy with focus on sample homogenization quality and necessary sample sizes per pooled sample. In the third experiment this improved sampling strategy was validated. Results from the first testing of the sampling procedure showed that the strategy is suitable, although some problems occurred. Especially the high spread in values among the replications caused high coefficients of variation (CV; mostly 40 – 60%). The improvement trial revealed that for the SM, which contains the slurry band, an intensive homogenization is required. In addition, suitable sample sizes (twelve auger samples and six soil monolith samples per pooled sample) have to be collected to obtain reliable SMN values. Following this enhanced sampling strategy in the final validation trial, the spread in values was considerably reduced and resulted in CV values of mostly < 20%. The method can be adapted to other fertilizer placement strategies and further row crops.
To compare both fertilizing strategies with respect to the spatial and temporal SMN dynamics as well as to the plant nutrient status two field trials were conducted using pig slurry on sandy soils in 2014 and 2015. Four treatments were tested: unfertilized control, broadcast application + MSF, injection, and injection + NI. Soil samples were taken using the new sampling strategy at several dates during the growing season. Plant samples were simultaneously collected to evaluate the plant P, Zn, and Mn status at different growth stages. In 2014, all fertilized N was displaced from the top soil layer of the broadcast treatment until the 6-leaf stage due to heavy rainfall, while N displacement was significantly smaller after slurry injection. The lateral movement of injected slurry N was negligible. In 2015, almost no displacement of fertilized N out of the top soil layer occurred independently of treatments, due to distinctly lower rainfall. The release of slurry N was delayed following broadcast application and large SMN concentrations were detected in the injection zones until the 10-leaf stage. The addition of a NI resulted in significantly increased NH4-N shares in the injection zone throughout the early growth stages (+ 46% in 2014 and + 12% in 2015 at 6-leaf stage). Thus, in 2014 SMN displacement was delayed, and in 2015 increased SMN concentrations were found around the slurry band, most probably due to lower N losses via denitrification. Furthermore, NI addition significantly increased the nutrient uptake by maize during early growth in both years. With P deficiency due to cold weather conditions in 2015, broadcast application showed higher P uptake until the 6-leaf stage (36 – 58%), while it was lower at the 8- (32%) and 10- (19%) leaf stages compared to slurry injection (+ NI). Zn availability was enhanced during early growth after slurry injection (+ NI) and Zn as well as Mn uptake were higher at harvest. Furthermore, dry matter yields were higher (2014) or equal (2015) compared to broadcast application. The P balances were decreased by 10 – 14 kg P ha-1, while Zn and Mn balances were excessive independent of treatments.
The field trials showed that after slurry injection, especially when combined with a NI, the applied nitrogen is located in a soil zone with better spatial availability for plant roots compared to broadcast application. Furthermore, the MSF can be substituted without affecting early growth of maize.
In conclusion, slurry injection leads to equal (or even higher) yields and enables farmers in northwestern Germany to reduce the P and N surpluses. This would support several goals concerning sustainable land use: Lower pollution of ground and surface waters, reduced emission of NH3, more efficient use of the limited rock P reserves, and less need of transporting organic manures out of regions with intensive animal husbandry and/or biogas production. However, slurry injection enhances the risk of N2O emissions, which contributes to climate change. Thus, for a final evaluation of the environmental impact a life cycle assessment would be worthwhile.
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Precambrian Geology of the Cottonwood Cliffs Area, Mohave County, ArizonaBeard, Linda Sue January 1985 (has links)
A belt of Early Proterozoic rocks crops out in the Cottonwood Cliffs area, northwest Arizona. The belt contains an eastern and a western assemblage separated by the Slate Mountain fault. The western assemblage consists of mafic to felsic metavolcanic rocks, metapelites, and metaconglomerates. The eastern assemblage consists of phyllites, felsic to intermediate metavolcanic rocks, metagraywackes, and metagabbro bodies. The belt is bounded to the east by foliated granodiorite. The Valentine granite intruded the belt on the west and north. Steeply-plunging lineations and fold axes, and northeast-trending vertical foliation dominate the structural fabric. The regional elongation direction is near-vertical, as indicated by mineral and pebble lineations, and is parallel to fold axes. Although only one deformational event is evident, the intensity of that event may have obliterated evidence of any earlier deformation. Tertiary basalts and the Peach Springs Tuff locally overly the metamorphic rocks. Cenozoic normal faults in the area are mostly of minor displacement.
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Memento mori: an archival strategy for documenting mortality on the Canadian frontier at Red Lake, Ontario, before 1950Richthammer, John Erwin Lavallée 21 January 2008 (has links)
Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study.
Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community.
This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier.
The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities. / February 2008
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Memento mori: an archival strategy for documenting mortality on the Canadian frontier at Red Lake, Ontario, before 1950Richthammer, John Erwin Lavallee 21 January 2008 (has links)
Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study.
Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community.
This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier.
The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities.
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Memento mori: an archival strategy for documenting mortality on the Canadian frontier at Red Lake, Ontario, before 1950Richthammer, John Erwin Lavallee 21 January 2008 (has links)
Memento Mori, Latin for “remember thy death,” implores us to be mindful that death is both inevitable and inescapable. What of the records created during the process of dying and about death? Based upon wide-ranging archival research into primary documents, this thesis explores the rich sources of both official, public records, and personal, private ones, relating to mortality on the small-town Canadian frontier before 1950. The community of Red Lake, Ontario, which was established on the frontier as the result of the Red Lake gold rush of 1926, is the subject of a case study.
Rather than merely cataloguing sources, this thesis illustrates that by adapting aspects from such archival appraisal methodologies as macroappraisal and documentation strategy, one is able to make available to researchers a wider range of sources relevant to the themes of dying and death. Specifically, by employing a documentation strategy methodology to identify and illuminate the records of human activities surrounding the functions of dying and death, archivists can offer to researchers the opportunity to locate relevant records wherever they may physically be. Since this is an Archival Studies thesis, it does not provide an historical analysis of dying and death, but is an archival study of the types of records related to the theme of mortality on the Canadian frontier: how those records were created, their character, and their capture and preservation in a small community.
This thesis is organized into three chapters and a conclusion. Chapter One explores some relevant trends in the secondary literature of three fields: archival appraisal and description, small town or local development on the frontier, and dying and death as human activities. Chapter Two sets the context in which the thesis analyzes mortality on the frontier by outlining the relevant history of the Red Lake District of Northwestern Ontario and its pioneers. The focus is especially on the gold-mining boom years from the mid-1920s until shortly after the Second World War. The heart of the thesis, Chapter Three, is a case study of the various records creators, human activities, and resultant records related to mortality. It is organized according to three phases or functional categories surrounding dying, death, and memorialization. The conclusion summarizes the usefulness of the case study, in light of the literature review in Chapter One. It also suggests areas of further research, including aspects not covered herein, of the records of dying and death on the Canadian frontier.
The documentation strategy, adapted from the original methods employed by archivists Helen Samuels and Richard Cox, was found to work best when deployed as a research and descriptive tool for exploring and documenting the records of mortality, more so than its original purpose as an acquisition tool. The strategy has wide-ranging usefulness discovering and then describing a “virtual” documentation universe relating to record-generating human functions and activities.
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