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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.
11

Implications of residue removal on soil quality in southwest Kansas

Ihde, Nicholas Adam January 1900 (has links)
Master of Science / Department of Agronomy / DeAnn R. Presley / Through the 2007 Energy Independence and Security Act, the U.S. government has set goals to decrease fossil fuel use and sustainably produce ethanol from biomass, rather than existing corn grain-based ethanol. In southwest Kansas, crop residues are necessary to protect soil from erosion and to contribute to soil organic carbon (SOC) levels, a key factor in most desirable characteristics of soil quality, and are positively related to soil and crop productivity. Our objective was to quantify the effect of different residue management treatments (residue continuously retained, residue continuously removed, and alternating year residue removal) on soil physical properties, chemical properties, and corn yield. For 2.5 years, measurements and samples were collected from a Hugoton loam (L) and Bigbow fine sandy loam (FSL) in southwest Kansas. Residue continuously removed decreased water stable aggregates ≥ 0.25 mm and mean weight diameter of aggregates in contrast to residue continuously retained treatments following two winter seasons at the Bigbow FSL site. In residue continuously removed treatment for the Bigbow FSL, dry aggregate size distribution (ASD) measurements at the soil surface in the fine sandy loam had higher levels of soil % < 0.84 mm (wind erodible fraction) during the winter season of 2008-2009 and 2009-2010 by 6% and 15%, respectively. No significant differences in wet aggregate stability and ASD were measured at the Hugoton L site. Soil temperature and moisture levels monitored during the winter season showed a higher frequency of freeze-thaw cycles, which can be destructive to aggregates, in residue continuously removed plots. During the winter seasons of 2008-2009 and 2009-2010, the residue continuously removed treatments experienced three more freeze-thaw cycles than the residue continuously retained treatments in the Bigbow FSL soil. Bulk density measurements were variable, and no significant differences due to residue treatment were observed in both the loam and fine sandy loam. Total C, N, and exchangeable K were significantly different in residue continuously retained and removed plots due to residue treatment following 1 year of establishment of the study in the FSL. Total C was 14 g kg-1 and 8.7 g kg-1 in the residue continuously retained and removed treatments, respectively. Total N was 0.3 g kg-1 higher in the residue continuously retained versus the residue continuously removed treatment in the FSL. Irrigated continuous corn in southwest Kansas produces a lot of biomass, and has been reported to create emergence problems in the past. Corn emergence was slightly higher in residue continuously removed treatments in both the spring of 2009 and 2010, but differences were insignificant. No significant treatment effects on corn grain yield were observed in the duration of the study.
12

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.
13

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).
14

Evaluation of maize and soybean intercropping on soil quality and nitrogen transformations in the Argentine Pampa

Regehr, Alison January 2014 (has links)
Agricultural intensification to increase food, feed, and fibre production has also resulted in environmental degradation, including poorer soil quality and high emissions of greenhouse gases (GHGs) like nitrous oxide (N2O). Intercropping, an agroecosystem management practice where more than one crop is planted on the same plot of land at the same time, promotes the complementary use of soil nutrients, and may improve soil quality and increase the retention of inorganic nitrogen (N) in the soil, thereby reducing N2O emissions. An experiment was conducted in Balcarce, Argentina to determine the impact of intercropping maize (Zea mays L.) and soybean (Glycine max (L.) Merr.), (either 1:2 or 2:3 rows of maize to soybean) on soil quality and soil N transformations after six cropping seasons. It was found that intercropping significantly improved soil quality over a six year period, as indicated by the soil organic carbon (SOC), soil total nitrogen (TN), soil light fraction organic matter (LF), and soil microbial biomass carbon (SMB-C). However, the soil quality also significantly improved in the sole crops over this time, and in 2012, only SMB-C was significantly (p<0.05) greater in the 2:3 intercrop than in the sole crops. Intercropping resulted in higher rates of gross nitrogen (N) mineralization than the sole crops, and the 2:3 intercrop resulted in higher rates of gross N immobilization than in the other treatments. However, the high rate of gross N mineralization resulted in a low relative NH4+ immobilization in both intercrops, signifying a lower potential for reducing soil NH4+ concentrations than in the sole crop treatments. Net N immobilization occurred in all treatment plots, which was desired at the end of the fallow period to reduce N losses from the soil. The 2:3 intercrop appeared to perform better than the 1:2 intercrop. However, further research needs to be conducted to determine the seasonal variations in N mineralization and immobilization, and to further examine the intercrop spatial arrangements to increase crop residue yield.
15

CARBON AND NITROGEN CYCLING IN GIANT CANE (ARUNDINARIA GIGANTEA (WALT.) MUHL.) RIPARIAN ECOSYSTEMS

Nelson, Amanda 01 May 2015 (has links)
Large stands of Arundinaria gigantea (Walt.) Muhl., called canebrakes, were vital to wildlife and lowland ecosystem functions and historically covered millions of acres in the southeastern United States. Since European settlement, human disturbance (i.e, clearing for agriculture and fire suppression) has caused giant canebrakes to become critically endangered ecosystems. Increasing evidence suggests the loss of canebrakes has directly impacted riparian ecosystems, resulting in increased soil erosion, poorer water quality, and reduced flood control. Cane's ecological importance has led to an increased interest in canebrake restoration in riparian zones. To examine the role that cane plays in nutrient cycling and to attempt to determine targeted restoration sites, a four phase research strategy was designed to determine physical and chemical properties of existing riparian stands of native giant cane and their associated soils. Phase one was a GIS analysis to determine what geographical features may be used in selecting sites within a landscape suitable for canebrake restoration. First, common physical site characteristics for 140 existing southern Illinois canebrakes were determined. Soil taxonomy and pH were used to represent soil characteristics and percent slope was used as a topographic metric. These factors, combined with digital elevation models and land cover in GIS were used to identify the potential suitability of sites within the watershed for canebrake plantings and general riparian restoration. The following soil characteristics were determined to be associated with giant cane success: percentage of area containing slopes of 3 percent or less, fine to coarse-silty textures, pH of 5.3 - 6.7, effective cation exchange capacity of less than 30 units, available water holding capacity greater than 0.12, bulk density of 1.37 - 1.65 g cm-3, and percent clay of 11 - 55. Eighty-percent of existing giant cane sites were found within these slope and soil characteristics. The total area of potential riparian canebrake landscapes based on these parameters is 13,970 hectares (35,600 acres) within the Cache River watershed. The remaining three phases examined the role that cane plays in nutrient cycling. Phase two determined the pools and cycling of nitrogen and carbon in canebrakes and compared those to nearby agricultural and forested riparian areas. Phase three quantified the N2O and CO2 fluxes from canebrakes and adjacent forested areas. Phase four included methods to quantify nutrient content of leaf litter and live leaves from existing canebrakes to estimate the nutrient use efficiency of cane. Further, a decomposition study was conducted to calculate the decomposition rate of cane leaves and to explore the litter quality attributes of giant cane. The primary purpose of phase two was to compare the effects of perennial riparian vegetation (giant cane and forest) and annual crops on soil quality, nitrogen cycling, and physical properties. This was to determine if any of them have a significant influence on giant cane distribution, while focusing on nitrogen dynamics to help determine why giant cane is a successful riparian buffer species. Five study sites in the Cache River watershed that had cane, agricultural fields (corn-soybean rotation), and forested areas adjacent to one another were selected. Data were collected on soil texture, carbon/nitrogen ratios, bulk density, nitrogen content (as ammonia and nitrate), and net nitrogen mineralization rates. The crop sites had significantly lower soil C:N ratios than both forest and cane (9.8:1 vs. 10.9:1 and 10.7:1, respectively), though all sites had ratios less than 25:1, indicating a tendency toward nitrogen mineralization. Forest soils had significantly higher rates of net mineralization than cane (19.0 μg m-2 day-1 and 6.6 μg m-2 day-1, respectively), with crop not significantly different from either cane or forest (8.0 μg m-2 day-1). Cane had higher levels of soil carbon and nitrogen when compared to forest and crop soils. Cane can be successful in wetter areas than previously thought, implying that the range of conditions that will support cane is broader than previously thought. Overall, there were few identifiable soil controls on giant cane distribution, or those that differentiate long-standing canebrakes from the nearby crop and forest land. For Phase three, nitrous oxide and carbon dioxide emissions were measured monthly for one year in riparian canebrakes and forests in southern Illinois to determine the rates of greenhouse gas (GHG) fluxes in bottomland riparian areas. Carbon dioxide emissions had a strong correlation with soil temperature (p < 0.001, r2= 0.54), but not with soil water content (p > 0.05), and were greater during the warmer months. Nitrous oxide emissions had a correlation with soil water content (p=0.470, r2 = 0.11), but no relation with soil temperature (p > 0.05), nor a difference across time. Vegetation type did not appear to influence GHG fluxes. Riparian CO2 and N2O emission rates were higher than documented cropland emissions, indicating riparian restoration projects to reduce NO3 delivery to streams may affect N2O and CO2 emissions resulting in an ecosystem tradeoff between water quality and air quality. Leaf deposition, N resorption efficiency and proficiency, and decomposition rates were analyzed in riparian stands of Arundinaria gigantea in southern Illinois for the first time in Phase four. Leaf litter was collected from five established canebrakes monthly over one year and a decomposition study was conducted over 72 weeks. Live leaves, freshly senesced leaves, and decomposed leaves were analyzed for carbon and nitrogen content. Leaf litterfall biomass peaked in November at twice the monthly average for all but one site, indicating a resemblance to deciduous leaf fall patterns. Nitrogen and carbon levels decreased 48% and 30%, respectively, between live leaves and 72 weeks decomposed. High soil moisture appeared to slow decomposition rates, perhaps due to the creation of anaerobic conditions. Cane leaves have low resorption proficiency and nutrient use proficiency, suggesting that these riparian canebrakes are not nitrogen limited. These results will help improve our understanding of the role that giant cane plays in a riparian ecosystem and help focus cane restoration efforts in southern Illinois.
16

RESTORATION OF RIPARIAN BUFFER FUNCTION IN RECLAIMED SURFACE MINE SOILS IN SOUTHERN ILLINOIS

Rahe, Nathan 01 May 2013 (has links)
Riparian buffers have been proven to reduce nutrient and sediment transport to streams in agricultural watersheds. Southern Illinois offers a unique opportunity to study functions of riparian buffers in reclaimed mine soils. In Perry County, Illinois three stream segments of Bonnie Creek, Galum Creek and Pipestone Creek were restored to their approximate original position following mining. Between 1980 and 2000, as part of the restoration, vegetative buffers of grasses and trees were planted along the streams to minimize nutrient and sediment inputs from adjacent restored agricultural land. Our research objective was to determine whether riparian soil function was being restored in the vegetated buffers by comparing multiple soil properties to the adjacent reclaimed soils in agricultural production. Four transects were established on each study site through the buffer and agricultural field. Ten one meter plots were evenly spaced along each transect in each of the land uses. In summers 2010 and 2011, water infiltration rates, bulk density, total carbon concentration, total nitrogen concentration, and C:N ratio measurements were made to assess the restoration of soil function. Soil water infiltration was significantly higher and bulk density was significantly lower in the riparian buffers compared to the adjacent agricultural fields. In the riparian buffer, roots likely helped to break up the soil adding pore space, which reduced the bulk density and increased the water infiltration rates. Soil total carbon, total nitrogen, and C:N ratio were significantly higher in the riparian buffers than the agricultural fields. The additional organic matter inputs from the roots of the riparian vegetation along with incorporation of litter from the soil macrofauna likely helped to increase the soil carbon and nitrogen levels compared to the agricultural fields. Even though the soil C:N ratio was significantly higher in the riparian buffers than the agricultural fields, more time is needed to restore the ratio to levels where nitrogen will be immobilized not mineralized in the riparian soils. Soil function in the riparian areas should continue to develop at a faster rate compared to the agricultural fields due to the impact of the perennial vegetation. Restoration of landscapes is not estimated by the return of structure alone, it also includes the re-establishment of function such as soil quality improvement, water quality improvement, and wildlife habitat restoration.
17

Avaliação de atributos físico-químicos do solo sobre palhadas de diferentes poáceas e adubação nitrogenada em semeadura direta na cultura do feijoeiro / Soil physical and chemical attributes of assessment on different poaceae straws and nitrogen in notillage culture bean

Oliveira, Jefferson Anthony Gabriel de [UNESP] 23 February 2016 (has links)
Submitted by JEFFERSON ANTHONY GABRIEL DE OLIVEIRA null (jeffunesp@yahoo.com.br) on 2016-05-08T22:02:27Z No. of bitstreams: 1 Tese Jefferson Final.pdf: 2156121 bytes, checksum: ef8e9ae3951c0e807526ae02fb2aa5bf (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-05-10T18:08:46Z (GMT) No. of bitstreams: 1 oliveira_jag_dr_ilha.pdf: 2156121 bytes, checksum: ef8e9ae3951c0e807526ae02fb2aa5bf (MD5) / Made available in DSpace on 2016-05-10T18:08:46Z (GMT). No. of bitstreams: 1 oliveira_jag_dr_ilha.pdf: 2156121 bytes, checksum: ef8e9ae3951c0e807526ae02fb2aa5bf (MD5) Previous issue date: 2016-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A cultura do feijoeiro (Phaseolus vulgaris L.) constitui-se numa das mais importantes explorações agrícolas tanto pela área cultivada quanto pelo valor de produção. O cultivo agrícola realizado visando a preservação dos atributos físicos, químicos e biológicos do solo é fundamental para a realização de uma agricultura sustentável. O objetivo do trabalho foi avaliar o cultivo do feijoeiro cultivar IAC, sobre diferentes palhadas de plantas de cobertura e doses de nitrogênio, aplicados em cobertura, e sua influência sobre a produção e qualidade de sementes e sobre os atributos físicos e químicos do solo. O experimento foi realizado na Fazenda de Ensino, Pesquisa e Extensão da UNESP - Campus de Ilha Solteira, localizada no município de Selvíria-MS. Os tratamentos foram compostos por 5 doses de nitrogênio (0, 40, 80, 120 e 160 kg ha-1) utilizando-se como fonte a ureia e 6 de palhadas (milho, milheto, Urochloa decumbens, Urochloa ruziziensis, Urochloa brizantha cv. MG5, Urochloa brizantha cv. Marandu), no cultivar IAC Formoso. As parcelas constaram de 6 linhas de 5 m sendo considerado como área útil as 4 linhas centrais a 0,5 m de cada extremidade. Após a colheita foram feitas análises dos componentes de produção do feijoeiro (número de vagens por planta, número de sementes por planta, número de sementes por vagem, massa de 100 sementes e produtividade), qualidade fisiológica de sementes (teste de germinação, teste de primeira contagem, índice de velocidade de germinação, comprimento de plântulas, teste de condutividade elétrica, tese de envelhecimento acelerado e teste de frio sem solo) e atributos físicos e químicos do solo, por meio da avaliação da resistência à penetração e análise química do solo, respectivamente. Conclui-se que: a produtividade do feijoeiro foi influenciada pelas plantas de cobertura nos dois anos, porém nem as maiores Produtividades e nem as menores ocorreram nas mesmas espécies. ara doses de nitrogênio em cobertura ocorreram variações entre os anos, sendo que em um dos anos para massa de 100 sementes foram obtidos ajustes dos dados a uma função linear, não ficando evidenciada nas demais avaliações efeito do nutriente sobre componentes de produtividade e produtividade do feijoeiro provavelmente devido a seca no período; as sementes obtidas apresentaram bom nível de qualidade fisiológica. A resistência à penetração de solo apresentou valores impeditivos ao pleno desenvolvimento da cultura. A as plantas de cobertura não influenciaram os atributos químicos de solo. / The common bean (Phaseolus vulgaris L.) is in one of the most important farms both the acreage and by production value. The agricultural cultivation carried out for the preservation of the physical, chemical and biological soil is essential for the achievement of a profitable and sustainable agriculture. The objective was to evaluate the bean cultivation IAC on different straws cover crops and nitrogen, applied in coverage , and its influence on the production and quality of seeds and about the physical and chemical soil. The experiment was conducted in Fazenda de Ensino, Pesquisa e Extensão da UNESP - Ilha Solteira, located in Selvíria-MS. The treatments consisted of five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1) using as source urea and 6 straws (maize, millet, Urochloa decumbens, Urochloa ruziziensis, Urochloa brizantha cv. MG5, Urochloa brizantha cv. Marandu) in IAC Formoso. The plots consisted of 6 lines of 5 m length. After harvest were made analysis of yield components (number of pods per plant, number of seeds per plant, number of seeds per pod, weight of 100 seeds and productivity), physiological seed quality (germination test, first count, speed germination index, seedling length, electrical conductivity, accelerated aging and cold test without soil) and physical characteristics and soil chemistry, by evaluating the resistance to penetration and chemical analysis of soil, respectively. In conclusion: bean yield was influenced by cover crops in two years, but not the highest productivity and even the smallest occurred in the same species; for nitrogen levels in coverage there were variations between years, and in one year for mass of 100 seeds were obtained settings data to a linear function, not being evidenced in other evaluations effect of nutrient on yield components and bean yield probably due to drought in the period; the obtained seeds showed good level of physiological quality. resistance to soil penetration values presented impede the full development of crop; cover crops did not affect the chemical aspects of soil, with all providing a good nutrient cycling.
18

Avaliação de atributos físico-químicos do solo sobre palhadas de diferentes poáceas e adubação nitrogenada em semeadura direta na cultura do feijoeiro /

Oliveira, Jefferson Anthony Gabriel de. January 2016 (has links)
Orientador: Marco Eustáquio Sá / Resumo: A cultura do feijoeiro (Phaseolus vulgaris L.) constitui-se numa das mais importantes explorações agrícolas tanto pela área cultivada quanto pelo valor de produção. O cultivo agrícola realizado visando a preservação dos atributos físicos, químicos e biológicos do solo é fundamental para a realização de uma agricultura sustentável. O objetivo do trabalho foi avaliar o cultivo do feijoeiro cultivar IAC, sobre diferentes palhadas de plantas de cobertura e doses de nitrogênio, aplicados em cobertura, e sua influência sobre a produção e qualidade de sementes e sobre os atributos físicos e químicos do solo. O experimento foi realizado na Fazenda de Ensino, Pesquisa e Extensão da UNESP - Campus de Ilha Solteira, localizada no município de Selvíria-MS. Os tratamentos foram compostos por 5 doses de nitrogênio (0, 40, 80, 120 e 160 kg ha-1) utilizando-se como fonte a ureia e 6 de palhadas (milho, milheto, Urochloa decumbens, Urochloa ruziziensis, Urochloa brizantha cv. MG5, Urochloa brizantha cv. Marandu), no cultivar IAC Formoso. As parcelas constaram de 6 linhas de 5 m sendo considerado como área útil as 4 linhas centrais a 0,5 m de cada extremidade. Após a colheita foram feitas análises dos componentes de produção do feijoeiro (número de vagens por planta, número de sementes por planta, número de sementes por vagem, massa de 100 sementes e produtividade), qualidade fisiológica de sementes (teste de germinação, teste de primeira contagem, índice de velocidade de germinação, comprimen... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The common bean (Phaseolus vulgaris L.) is in one of the most important farms both the acreage and by production value. The agricultural cultivation carried out for the preservation of the physical, chemical and biological soil is essential for the achievement of a profitable and sustainable agriculture. The objective was to evaluate the bean cultivation IAC on different straws cover crops and nitrogen, applied in coverage , and its influence on the production and quality of seeds and about the physical and chemical soil. The experiment was conducted in Fazenda de Ensino, Pesquisa e Extensão da UNESP - Ilha Solteira, located in Selvíria-MS. The treatments consisted of five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1) using as source urea and 6 straws (maize, millet, Urochloa decumbens, Urochloa ruziziensis, Urochloa brizantha cv. MG5, Urochloa brizantha cv. Marandu) in IAC Formoso. The plots consisted of 6 lines of 5 m length. After harvest were made analysis of yield components (number of pods per plant, number of seeds per plant, number of seeds per pod, weight of 100 seeds and productivity), physiological seed quality (germination test, first count, speed germination index, seedling length, electrical conductivity, accelerated aging and cold test without soil) and physical characteristics and soil chemistry, by evaluating the resistance to penetration and chemical analysis of soil, respectively. In conclusion: bean yield was influenced by cover crops in two years, but n... (Complete abstract click electronic access below) / Doutor
19

Assessment of indicators of pollution of soil and water and its implications in supply system of public Juazeiro North - CE / AvaliaÃÃo de indicadores de poluiÃÃo de solos e Ãguas e suas implicaÃÃes no sistema de abastecimento pÃblico de Juazeiro do Norte - CE

Joelma Lima Oliveira 29 August 2014 (has links)
nÃo hà / This study evaluates the indicators of soil and water and its implications for the public supply of Juazeiro system pollution from interactions between aquifers and soils that makes up part of the drainage area of the stream of the Apes. For this, a characterization of the soils of the area as the physical, chemical and biological aspects was conducted through qualitative indicators of total organic carbon, total nitrogen, basal respiration and C / N ratio. Surface waters were also characterized in terms of COD and BOD parameters and groundwater for the parameters of Ammonia, Nitrite, Nitrate and chloride. The data obtained in the characterization of the soils of the study area were analyzed using multivariate statistical methods Principal Component Analysis and Cluster Analysis Hierarchical Agglomerative; and those obtained in the characterization of surface water were contrasted with the framework set out by the CONAMA Resolution No. 357 for classes of freshwaters. Data from qualitative monitoring of groundwater, provided by CAGECE, were analyzed regarding the classification according to the predominant uses, by Resolution No. 396 of CONAMA and how to meet potability standards, by Ordinance No. 9214 MS. It was found that the soils of the drainage area of &#8203;&#8203;the stream of the Apes are degraded by human interference in the area, standing surface water polluted by sewage to the fullest extent analyzed, not fitting into any of the classes of freshwater, based the parameters analyzed. Of groundwater supply wells included in the study area meet the required legal standards, but already show signs of pollution by domestic sewage. / Este trabalho procura avaliar os indicadores de poluiÃÃo de solos e Ãguas e suas implicaÃÃes no sistema de abastecimento pÃblico de Juazeiro do Norte, a partir das interaÃÃes entre os aquÃferos e os solos que compÃe parte da zona de drenagem do riacho dos Macacos. Para isso, foi realizada uma caracterizaÃÃo dos solos da Ãrea quanto os aspectos fÃsicos, quÃmicos e biolÃgicos, atravÃs dos indicadores qualitativos de carbono orgÃnico total, nitrogÃnio total, respiraÃÃo basal e relaÃÃo C/N. Foram caracterizadas tambÃm as Ãguas superficiais quanto aos parÃmetros de DQO e DBO e as Ãguas subterrÃneas quanto aos parÃmetros de AmÃnia, Nitrito, Nitrato e Cloreto. Os dados obtidos na caracterizaÃÃo dos solos da Ãrea de estudo foram analisados atravÃs dos mÃtodos de estatÃstica multivariada AnÃlise de Componentes Principais e AnÃlise de Cluster Aglomerativa HierÃrquica; e os obtidos na caracterizaÃÃo das Ãguas superficiais foram contrastados com o enquadramento previsto pela ResoluÃÃo n 357 do CONAMA para classes de Ãguas doces. Os dados de monitoramento qualitativo das Ãguas subterrÃneas, fornecidos pela CAGECE, foram analisados, quanto ao enquadramento segundo os usos preponderantes, pela ResoluÃÃo n 396 do CONAMA e quanto ao atendimento aos padrÃes de potabilidade, pela Portaria MS n 9.214. Constatou-se que os solos da Ãrea de drenagem do riacho dos Macacos encontram-se degradados pelas interferÃncias antrÃpicas na Ãrea, estando as Ãguas superficiais poluÃdas por esgotos em toda a extensÃo analisada, nÃo se enquadrando em nenhuma das classes de Ãgua doce, com base nos parÃmetros analisados. As Ãguas subterrÃneas dos poÃos de abastecimento inseridos na Ãrea de estudo atendem aos padrÃes legais exigidos, mas jà apresentam indÃcios de poluiÃÃo por esgotos domÃsticos.
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Can Soil Microbial Activity Be Improved With the Use of Amendments?

Kruger, Matthew Wayne January 2020 (has links)
Low microbial activity and associated nutrient cycling are concerns in agricultural problem soils. The objectives of this study were to investigate microbial response on problem soils to amendments, drying-wetting cycles, and the interaction of amendments and drying-wetting cycles. In this laboratory study, soil carbon dioxide (CO2) flux was measured from thermal desorption treated soils and saline soils in response to Proganics, spent lime, and composted beef manure applications. Microbial activity was measured through CO2 flux and its rate of change, permanganate oxidizable C, and residual inorganic nitrogen. Proganics had the greatest ability to elevate and sustain microbial activity on problem soils, but spent lime and compost had the greatest potential to improve microbial mediated nitrogen mineralization. In conclusion, spent lime and compost can be effective amendments for improving soil quality of saline and thermal desorption treated problem soils to increase microbial activity and associated nitrogen cycling.

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