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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study of the microbial and mycorrhizal effects on Japanese Larch growth in soil on opencast coal workings in South Wales

Berry, Heather Fiona January 1994 (has links)
No description available.
2

Evaluation of the lime requirements of some soils for grass production

Bailey, J. S. January 1986 (has links)
No description available.
3

Environment and livelihood systems in the forest-savanna interface : a study in Brong Ahafo region, Ghana

Tuson, Jon January 2001 (has links)
No description available.
4

Soil quality and corn-soybean yields as affected by winter rye at three sites in the U.S. Corn Belt

Eidson, Christopher D. 01 September 2015 (has links)
No description available.
5

Dynamics and Characterization of Soil Organic Matter on Mine Soils 16 Years after Amendment with Topsoil, Sawdust, and Sewage Sludge

Bendfeldt, Eric S. 11 April 1999 (has links)
The present state and future prospect of the world's soil resources has prompted scientists and researchers to address the issue of soil quality and sustainable land management. Soil quality research has focused on intensively-managed agricultural and forest soils, but the concept and importance of soil quality is also pertinent to disturbed systems such as reclaimed mine soils. The restoration of soil function and mine soil quality is essential to long-term ecosystem stability. The objectives of this study were (i) to determine the comparative ability of topsoil, sawdust, and sewage sludge amendments, after 16 years, to positively affect mine soil quality using the following key soil quality variables: organic matter content, aggregate stability, and mineralizable nitrogen, (ii) to determine the effects of these key soil quality variables on plant productivity, and (iii) to determine the comparative ability of trees and herbaceous plants to persist and to conserve or maintain mine soil quality. In 1982, a mined site was amended with seven different surface treatments: a fertilized control (2:1 sandstone:siltstone), 30 cm of native soil + 7.8 Mg ha-1 lime, 112 Mg ha-1 sawdust, and municipal sewage sludge (SS) at rates of 22, 56, 112, and 224 Mg ha-1. Four replicates of each treatment were installed as a randomized complete block design. Whole plots were split according to vegetation type: pitch x loblolly pine hybrid (Pinus rigida x taeda) trees and Kentucky-31 tall fescue (Festuca arundinacea Schreb.). Soil analyses of composite samples for 1982, 1987, and 1998 were evaluated for changing levels of mine soil quality. The positive effect of these organic amendments on organic matter content, total nitrogen, and other soil parameters was most apparent and pronounced after 5 growing seasons. However, after 16 years, soil organic matter content and total nitrogen appear to be equilibrating at about 4.3 and 1.5%. There was a significant difference in organic matter content and nitrogen mineralization potential between vegetation types. Organic matter inputs by vegetation alone over the 16-yr period in the control plots resulted in organic matter and nitrogen mineralization potential values comparable to levels in the organically amended plots. The results suggest that about 15 years is needed for climate, moisture availability, and other edaphic features to have the same influence on overall organic matter decomposition, N accretion, organic nitrogen mineralization levels, system equilibrium, and overall mine soil quality as a one-time 100-Mg ha-1 application of organic amendment. Tree volume and biomass were measured as indices of the effects of organic matter content 16 years after initial amendment. Individual tree volumes of the sawdust, 22, 56, and 112 Mg ha -1 SS treatments retained 18 to 26% more volume than the control, respectively. Overall, fescue production was the same among treatments. Organic amendments improved initial soil fertility for fescue establishment, but it appears that they will have little or no long-lasting effect on plant productivity. / Master of Science
6

Testing the safety-net hypothesis in hedgerow intercropping : water balance and mineral N leaching in the humid tropics

Suprayogo, Didik January 2000 (has links)
No description available.
7

A methodology for the statistical and spatial analysis of soil contamination in GIS

Korre, Anna January 1997 (has links)
No description available.
8

ASSESSING INDICATORS OF FOREST RESTORATION SUCCESS ACROSS A CHRONOSEQUENCE OF AFFORESTED CROPLAND IN CYPRESS CREEK NATIONAL WILDLIFE REFUGE

Herrmann, Maggie C 01 May 2023 (has links) (PDF)
Since 1982, the state of Illinois has afforested over 100,000 acres of abandoned or marginal cropland. Afforestation, the planting of trees on land not in forest cover, is a sustainable forest management practice that has been shown to store carbon, increase plant diversity, improve soil and water quality, and assist in flood abatement. Our research seeks to develop practical soil and vegetative indicators that can be used by researchers and land managers alike to accurately assess changes to ecosystem function following land use shifts. To assess forest restoration success in terms of ecological function, seven ecological indicators were measured across a chronosequence of 50 afforested sites and 20 mature forested sites. Soil indicators: bulk density, aggregate stability, total nitrogen, total carbon, and labile carbon, and vegetation indicators: forest productivity and stocking density were assessed for each site. Additional sampling was completed on 25 nearby agriculture fields for each of the five soil indicators. Our data were analyzed using an analysis of variance test with multiple comparisons to examine differences among indicator values by land use category. Overall, soil indicator bulk density significantly decreased across afforested sites with stand age, whereas indicators aggregate stability, labile carbon, and total carbon significantly increased across afforested sites with stand age. Linear regression analyses were used to assess the change in indicator values with stand age. Additional linear regression analyses were used to assess the change in indicator values with site index, and significant results were recorded for 3 out of the 5 soil indicators. Indicator bulk density displayed a significant negative relationship with site index, and indicators aggregate stability and total carbon displayed a significant positive relationship with site index. Overall, our results indicated that four out of the five soil parameters measured were successful indicators of restored ecological function in afforested sites. Furthermore, we believe that the inclusion of vegetation indices forest productivity and stocking density provides vital information into forest succession and a better understanding of how productive sites benefit soil quality.
9

MATHEMATICAL MODELLING OF SOIL DIVERSITY INDICES UNDER DIFFERENT USES AND MANAGEMENTS

SILVA, Raimunda Alves 06 March 2017 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-10-04T20:06:24Z No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5) / Made available in DSpace on 2017-10-04T20:06:24Z (GMT). No. of bitstreams: 1 RaimundaSilva.pdf: 3007003 bytes, checksum: 6d2583372b22c581e239bf77c0d1338e (MD5) Previous issue date: 2017-03-06 / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão / ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of Maranhão state, Brazil. It were installed 130 pitfall traps in five areas with different management (millet, soybean, maize, eucalyptus, and pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. The geostatistical analysis was evaluated by a semivariogram, adjusted to a geostatistical, spherical, gaussian or exponential model. The multifractality was analyzed by the current method, in successive segments of different sizes of 2k , k=0 a k= 7 in the range of q = +10 to q = -10. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability. For the areas of millet, maize, eucalyptus, anthropized Cerrado and pasture the Shanon diversity index obtained pure nugget effect. For the areas of millet, maize, anthropized Cerrado and pasture, the total diversity index was adjusted to the gaussian model. Only for the areas of soybean and pasture the staggered semivariograms showed similarity in the spatial variability of indexes, indicating that they behave similarly. The multifractality generated generalized dimension, D0, for all the indexes in the millet area, with invariant values, D0 = 1.000 ± 0.000. The singularity spectra were curves in concave parables with greater or smaller asymmetry for all areas sampled. In general, the fauna of soil presented spatial variability and multifractal parameters. / ABSTRACT: Soil is the habitat for a number of living organisms that perform essential functions to the ecosystem. The present work aimed to determine the edaphic diversity in large groups under different uses and management of the soil in Cerrado Biome. The study was developed in the city of Mata Roma (3º 70 '80.88' 'S and 43º 18' 71.27 '' W), in the eastern region of the State of Maranhão, Brazil. Were installed 130 pitfall traps in five areas with different management (Millet, Soybean, Maize, Eucalyptus, and Pasture) and two reference areas with natural vegetation with different uses (anthropized Cerrado and preserved Cerrado). The traps remained in the field for a period of seven days, after this, the contents were maintained in plastic bottles and taken to the laboratory, where they were sampled and identified in large groups (orders and family). After identification, the biodiversity indexes were determined: (Shanon index, Pielou, Average and total richness and abundance). The data were analyzed using descriptive statistics and multivariate techniques using group dissimilarity. 20,995 arthropods were collected throughout the study. The highest abundance was found for millet (9,974 individuals), and the lowest abundance values were reported for soybean (222) and maize (824), respectively. The highest biodiversity index is reported for the soybean area (2.69), although there is less abundance, in this area, the groups are evenly distributed due to the homogeneous management in the study area. The main axis in the analysis of the main components (PCA) explained 50.9% of the correlation of the groups with the sampled areas. The dendrogram had demonstrated that the area of soybean and maize are similar and had isolated the area of millet with the most dissimilar in relation to the others. The use and management of the soil in the study areas determine the occurrence of soil arthropods in function of food availability.
10

Monitoring the Impact of Scott Base in Antarctica: A Recent Evaluation of Wastewater, Water and Soil Quality at Pram Point, Ross Island.

Williams, Thomas Mervyn January 2012 (has links)
Antarctica is widely perceived as the most untouched continent on Earth. However, increasing anthropogenic presence in Antarctica is creating continual pressure on the pristine environment. To protect the Antarctic environment, monitoring and reporting procedures must be a priority for Nations wishing to conduct research on the continent. A significant contributor to environmental degradation is poor waste management and waste disposal, in particular the discharge of sewage and wastewater into the marine environment. This study provides information on the potential impact of Scott Base wastewater on the local marine environment, which can be used to improve operating systems and as a tool to ultimately reduce the environmental footprint of the base. This study investigated the characteristics of the sewage from Scott Base, Antarctica, and the water quality within the wastewater discharge plume beneath the sea ice. Results from seawater analysis were then compared with Redvers (2000) to give an indication of how contamination levels have changed over the last decade. Results show that in the vicinity of the wastewater outfall, seawater samples contained no faecal coliforms or Escherichia coli. Nitrate-Nitrogen (NO3ˉ- N) concentrations were recorded up to 1.1 mg/L, while phosphate (PO43-) ranged from 0.28 to 0.45 mg/L. The pH ranged from 7.84 to 7.92. Dissolved oxygen ranged between 10.05 and 13.02 mg/L, and conductivity between 48.4 to 55.2 mS/cm. Concentrations of copper (Cu), manganese (Mn), and zinc (Zn) were greatest at sites within 30m of the outfall. Iron (Fe) and nickel (Ni) were detected at most sites within the plume. The general spatial extent of the plume is now approximately 50m long-shore, and 30m offshore. Compared to Redvers (2000) the current plume is more localised, with a reduction of approximately 100-125m long-shore and 10-20m offshore. Faecal coliforms have reduced to no longer be detected within the plume, while dissolved oxygen and total organic carbon concentrations in the plume have increased, and conductivity has decreased. Soils surrounding Scott Base were also investigated as a potential source of trace metal (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) discharge to the marine environment. Total recoverable soil metal concentrations and readily leachable metal concentrations were measured. Sites were selected on the basis of being potential sources of contamination (fuel storage areas or refuelling areas), or potentially effecting the marine environment (shorelines). Results show that the greatest concentrations of metals and readily leachable metals were found primarily along the shoreline, and not necessarily where contamination related to current base activities is likely to occur. The results indicate that historic contamination may still persist in the terrestrial environment, and has the potential to be transported into the marine environment. Domestic and drinking water samples were analysed for trace metals and nutrients to ensure that contaminants from the wastewater outfall were not entering the reverse osmosis plant. Results show that the drinking water meets New Zealand Drinking Water Standards (Ministry of Health, 2008).

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