Soil erosion from American cropland poses a problem to society in many ways. Ground and surface water is polluted by chemicals carried on the eroded soil, silt builds up in rivers and other water bodies, soil particles carried by wind pollute the air, and finally there is a decline in the productivity of the remaining cropland soil. The rate that soil is eroded from cropland is directly affected by the type of crops planted, tillage systems used and government agricultural programs. This thesis presents the economic costs of soil erosion from cropland and the private and social benefits that can be obtained by reducing erosion rates. Many conservation programs have been less than effective in controlling erosion levels and some commodity and income programs have actually increased erosion rates. A survey of government policies and their various effects on soil erosion rates is included in this thesis. Alternative government policy options are presented.

Soil erosion has been recognised as a global threat against the sustainability of natural ecosystem. The work in this thesis has been undertaken to assist in combating this threat, and addresses the soil erosion issues associated with urban construction activities. The Revised Universal Soil Loss Equation (RUSLE) was employed in this research work and the parameters associated with the model were calibrated. This model was chosen for calibration, as it has been proven to be an easy to use tool yet providing reasonable results. Large scale rainfall simulators developed at UWS were used for rainfall simulation at two sites with diverse soil types: dispersive clayey soils at Penrith and highly permeable sandy soil at Somersby (Both in New South Wales, Australia). It is concluded that RUSLE can be successfully used in single storms for erosion prediction. Calibrated values of RUSLE parameters are useful in predicting soil erosion from the construction sites in NSW. It is also identified that in rolled smooth land condition, clayey soils are more erodible than sandy soil. Specific support practices such as short grass strips, gravel bags and silt fences are identified as very effective erosion control measures in reducing soil erosion from 45% to 85%. These results will be very useful in soil erosion prediction planning and conservation management in NSW. / Master of Engineering (Hons)

Thesis (M.S.)--Humboldt State University, 2008. / Includes bibliographical references (leaves 45-47). Also available via Humboldt Digital Scholar.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 84-88). Also available on the Internet.

Thesis (M.A.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains v, 38 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 26-28).

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 84-88). Also available on the Internet.

Thesis (Ph.D.)(Agricultural Economics)--University of Pretoria, 2007. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Made available in DSpace on 2014-06-11T19:32:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-12-16Bitstream added on 2014-06-13T21:04:34Z : No. of bitstreams: 1 gomes_ln_dr_botfca.pdf: 919435 bytes, checksum: 21a680807df6222aa5f0029cc1b06f57 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / A ação de processos erosivos em áreas rurais constitui um dos principais problemas da agricultura mundial. A falta de ações conservacionistas nessas áreas, somadas às ações de intemperismo proporciona perda considerável de solos agricultáveis, prejuízo ambiental que é acrescido pela poluição e assoreamento dos rios. Na tentativa de potencializar a produção de alimentos e visando atender à demanda proporcionada pelo crescente aumento da população, técnicas como o cultivo mínimo e o plantio direto contribuem para que haja equilíbrio entre produção agrícola e o meio ambiente, interesse patente das gerações presente e futura. Contudo, notadamente em pequenas propriedades rurais, é comum ainda o uso de tecnologias convencionais, como implantação de cordões de contorno. Em pequena propriedade rural, em área de reforma de pastagem, foram locados quatro cordões de contorno utilizando trator e arado convencional. Com estação total foram realizados dois levantamentos planialtimétricos, logo após a construção dos cordões de contorno e decorridos doze meses. Os dados foram processados pelos softwares DataGEOSIS e LandDESKTOP, onde foram criados artifícios para o cálculo do volume admissível nos canais dos cordões de contorno nas duas épocas distintas com o objetivo de verificar a validade da modelagem numérica do terreno na caracterização da movimentação de solo nos canais. Com base na metodologia adotada foi possível concluir que o modelo numérico do terreno permitiu avaliar o volume de solo movimentado nas três feições de relevo estudadas (relevo natural à montante, fundo do canal e camalhão), quando se constatou que a diminuição da capacidade de acúmulo de águas pluviais nos cordões de contorno foi em média 20,76% em um ano. / The actions of the erosive process in rural areas constitutes one of the most serious problem in agriculture worldwide. The lack of conservationist actions in those areas added to the weathering actions led to a preoccupying agricultural soil loss, environmental damage increased by pollution and rivers sedimentation. To attempt to increase the food production and aiming to help the food demand due to the population increasing, techniques like minimum tillage and no tillage contribute to the equilibrium between agricultural production and environment, what is the interest of the current and future generations. However, mainly in small farms it is common the use of conventional techniques like the contour lines implantation. In an area of pasture reformation into a small farm, four contour lines were demarcated using a tractor and conventional plow. Using a total station were made two topographic survey just after the contour lines demarcation and after twelve months. The data were processed using the software DataGEOSIS and LandDESKTOP, where artifices were created to the calculation of the possible water volume into channels of contour lines for the two dates of surveying, aiming to verify the validity of numerical terrain model to the soil movement characterization into channels. Considering the methodology used was possible to conclude that the numerical terrain model allowed to evaluate the soil volume alteration in the three relief forms studied (natural relief above, channel bottom and soil ridge), when was verified that the water storage capacity into contour lines decreased in average 20,76 % in a year.

Made available in DSpace on 2014-06-11T19:35:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-16Bitstream added on 2014-06-13T19:24:48Z : No. of bitstreams: 1 queiroz_rp_dr_ilha.pdf: 1433368 bytes, checksum: da394fb054e147bac86fee358da18db7 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / As culturas agrícolas são responsável pela terça parte da produtividade de grãos destinada à alimentação brasileira, desempenhando importante papel econômico-financeiro à nação. Desta forma, no ano agrícola 2005/2006, na Fazenda de Ensino, Pesquisa e Extensão da Faculdade de Engenharia/UNESP- Campus Ilha Solteira, localizada no município de Selvíria-MS (20º22´S, 51º22´W e 335m de altitude média), foram estudadas a variabilidade e a dependência espacial entre alguns atributos do solo e componentes de produção da soja, quando rotacionada após milho safrinha, sobre um Latossolo Vermelho Distroférrico. Assim, foram estudadas as correlações lineares e espaciais entre os atributos do solo (MA, MI, PT, DS e MO) e os da planta (AP, AV, NV, NG, MM e PG), com o objetivo de selecionar aquele que melhor se apresentasse para explicar a produtividade de grãos de soja. Para tanto, na área agrícola da FEPE/Cerrado, instalou-se a malha geoestatística contendo 124 pontos amostrais, com espaçamento de 10,0 x 10,0 m, 5,0 x 5,0 m e 1,67 x 1,67 m entre eles, numa área total de 4000 m2. Do ponto de vista linear e espacial, foi observada correlação direta entre a macroporosidade, avaliada de zero-0,10 m de profundidade e a produtividade de grãos de soja, sugerindo-a como indicadora da qualidade física do solo pesquisado. / The crops are responsible for third of grain yield for the Brazilian food, performing economic and financial importance to the nation. Thus, in the agricultural year 2005/2006, the Finance of Education, Research and Extension, Universidade/UNESP-Campus Ilha Solteira, located in Selvíria-MS (20 ° 22'S, 51 º 22'W and 335m of altitude average) , evaluated the variability and spatial dependence among soil attributes and components of the soybean production, where rotational after winter maize on an Oxisol. Therefore, we studied the linear and spatial correlation between soil attributes (MA, MI, PT, DS, and MO) and the plant (AP, AV, NV, NG, MM and PG) with the goal of selecting that better to present to explain the grain yield of soybean. Thus, the area's agricultural FEPE / Cerrado, installed to geostatistics mesh containing 124 sampling points with spacing of 10.0 x 10.0 m, 5.0 x 5.0 x 1.67 m 1.67 m between them, a total area of 4000 m2. From a linear and space, was a direct correlation between the macroporosity, evaluated from zero-0, 10 m depth and grain yield of soybean, suggesting it as an indicator of soil physical quality searchable.

Resumo: A ação de processos erosivos em áreas rurais constitui um dos principais problemas da agricultura mundial. A falta de ações conservacionistas nessas áreas, somadas às ações de intemperismo proporciona perda considerável de solos agricultáveis, prejuízo ambiental que é acrescido pela poluição e assoreamento dos rios. Na tentativa de potencializar a produção de alimentos e visando atender à demanda proporcionada pelo crescente aumento da população, técnicas como o cultivo mínimo e o plantio direto contribuem para que haja equilíbrio entre produção agrícola e o meio ambiente, interesse patente das gerações presente e futura. Contudo, notadamente em pequenas propriedades rurais, é comum ainda o uso de tecnologias convencionais, como implantação de cordões de contorno. Em pequena propriedade rural, em área de reforma de pastagem, foram locados quatro cordões de contorno utilizando trator e arado convencional. Com estação total foram realizados dois levantamentos planialtimétricos, logo após a construção dos cordões de contorno e decorridos doze meses. Os dados foram processados pelos softwares DataGEOSIS e LandDESKTOP, onde foram criados artifícios para o cálculo do volume admissível nos canais dos cordões de contorno nas duas épocas distintas com o objetivo de verificar a validade da modelagem numérica do terreno na caracterização da movimentação de solo nos canais. Com base na metodologia adotada foi possível concluir que o modelo numérico do terreno permitiu avaliar o volume de solo movimentado nas três feições de relevo estudadas (relevo natural à montante, fundo do canal e camalhão), quando se constatou que a diminuição da capacidade de acúmulo de águas pluviais nos cordões de contorno foi em média 20,76% em um ano. / Abstract : The actions of the erosive process in rural areas constitutes one of the most serious problem in agriculture worldwide. The lack of conservationist actions in those areas added to the weathering actions led to a preoccupying agricultural soil loss, environmental damage increased by pollution and rivers sedimentation. To attempt to increase the food production and aiming to help the food demand due to the population increasing, techniques like minimum tillage and no tillage contribute to the equilibrium between agricultural production and environment, what is the interest of the current and future generations. However, mainly in small farms it is common the use of conventional techniques like the contour lines implantation. In an area of pasture reformation into a small farm, four contour lines were demarcated using a tractor and conventional plow. Using a total station were made two topographic survey just after the contour lines demarcation and after twelve months. The data were processed using the software DataGEOSIS and LandDESKTOP, where artifices were created to the calculation of the possible water volume into channels of contour lines for the two dates of surveying, aiming to verify the validity of numerical terrain model to the soil movement characterization into channels. Considering the methodology used was possible to conclude that the numerical terrain model allowed to evaluate the soil volume alteration in the three relief forms studied (natural relief above, channel bottom and soil ridge), when was verified that the water storage capacity into contour lines decreased in average 20,76 % in a year. / Orientador: Lincoln Gehring Cardoso / Coorientador: João Carlos da Costa Catalão Fernandes / Banca: Zacarias Xavier de Barros / Banca: Vilmar Antonio Rodrigues / Banca: Sérgio Pascola de Campos / Banca: Fernanda Leite Ribeiro / Doutor