Papers by Walquiria Machado
Anais da Academia Brasileira de Ciencias, Jan 25, 2018
Retaining sugarcane straw over the soil after harvesting can improve soil structure and increase ... more Retaining sugarcane straw over the soil after harvesting can improve soil structure and increase soil carbon stabilization, mainly in macroaggregates. We evaluated the carbon content in the aggregate classes in areas under burn and no-burn (adopted for five years) sugarcane management systems, focusing on the superficial layer (0.00-0.20 m). The experiment was carried in an Oxisol and the treatments consisted in burnt sugarcane, manual harvest; burnt sugarcane, mechanized harvest; and no-burn, mechanized harvest. The retention of sugarcane straw on the soil surface is justified by the increase in carbon content and carbon stock in the surface layer (0.00-0.20 m) by restructuring of the soil, even though it cannot match the structure of the soil under native forest. Our results suggest that in no-burn management the carbon not occluded inside aggregates was important to increase carbon stabilization in soil and that more attention should be given to macroaggregates 2.00-8.00 mm prese...
Semina: Ciências Agrárias, 2016
Vinasse is a potassium-rich waste generated in large amounts by the ethanol production that, appl... more Vinasse is a potassium-rich waste generated in large amounts by the ethanol production that, applied in the soil, can promote changes in water dispersible clay and in its physical quality. The aim of this study was to evaluate the clay dispersion of Oxisols after vinasse application and correlate it with some chemical attributes. Samples were collected in two Oxisols (155 and 471 g of clay kg-1), put in pots, received dosages of vinasse (0, 50, 100, 150 and 200 m3 ha-1) and remained incubated during 120 days. Phosphorous, organic carbon, pH H2O, pH KCl, pH CaCl2, Al3+, H+Al3+, Ca2+, Mg2+, K+, Na+, Delta pH and the proportion between monovalent and bivalent cations have been evaluated and correlated with the clay flocculation degree. Vinasse changed almost all chemical variables in both soils and increased the flocculation in the sandy soil, but did not change the clayey one. Delta pH, Mg2+ and K+ significantly correlated with the flocculation degree in the sandy soil. It is possible...
Revista Sociedade Natureza, Nov 3, 2009
The human survival is closely connected to the use we do of our natural resources existing in our... more The human survival is closely connected to the use we do of our natural resources existing in our planet, in a way that this connection depends on the consumption habits and apprehension of these goods. During the last century (XX), we noticed a boom of technology and a great changing in the habits of the world population. With the information globalization and knowledge, the environmental situation in the planet was more evident, and we concluded that the mankind should rethink the model of exploration of the natural resources. (Stockholm, Rio-92, Agenda 21 among others), and even the social paradigms. The proposal of this work is make a factual approach in this ocean of knowledge and discussions about the environmental problems currently presented in our society. It was chosen as a study unity the Hydrographic basin, specifically the physical processes presented at Ribeirão das Marrecas micro basin river. Collecting the data, basically a physical environmental inventory, characterizing the environment as most detailed as possible of the micro basin by consulting the cartographic documents available and bibliographic information. To the developing of the micro basin hydrographical of Ribeirão das Marrecas, it was necessary the confection of several themes letters. Each item of the inventory was translated into basic themes maps: geological, geo morphological, downward slopes maps, hydrographic, climatologically, the use of the soil and pedological. The intervention unit "hydrographical basin" presents Sociedade & Natureza, Uberlândia, Special Issue, 953-960, May, 2005 954 advantages and disadvantages. The main advantage is that this territorial unit relates the effects/causes of the environmental more clearly and easier measuring. So, we intend to establish the recovery proposals presenting some mitigating alternatives or solving conflicts in the area of the micro basin. Due the region peculiarities, concerning to the dynamic economical and social factors, it becomes imperative that the civil responsibility takes it over in response to the environmental passive, whether they come from naturals means or from the action of man.
Geografia, Oct 11, 2010
RESUMO: A microbacia Hidrográfica do Ribeirão dos Apertados, localizada entre os municípios de Lo... more RESUMO: A microbacia Hidrográfica do Ribeirão dos Apertados, localizada entre os municípios de Londrina e Arapongas no norte do Estado do Paraná, caracteriza-se pela presença de solos férteis de Nitossolos (TRE), por ser produtora de grãos (soja, milho e trigo), apresentando um quadro de degradação ambiental comum às outras microbacias da região, ou seja, ausência da mata ciliar em alguns pontos e presença de algumas formas de processos erosivos. Tendo como base o manejo e algumas práticas conservacionistas implementadas por alguns agricultores da região, em parcerias com a Emater e algumas firmas de tecnologia agrícola, este estudo teve como objetivo avaliar a eficácia destas práticas e o sistema de manejo na área em questão, com vistas à manutenção do equilíbrio dos recursos ambientais, de modo a proporcionar um desenvolvimento satisfatório da atividade agrícola. As técnicas conservacionistas na microbacia se iniciaram com a construção de terraços para evitar o carreamento de nutrientes e sedimentos e, em seguida com o restabelecimento da mata ciliar e a recuperação das estradas rurais em algumas áreas. Posteriormente foi desenvolvido o manejo do solo, com base na introdução do Sistema de Plantio Direto. O resultado destas ações, principalmente da ação conjunta dos técnicos responsáveis com os agricultores desta região efetivaram melhoria das condições ambientais para o desenvolvimento da atividade agrícola com o aumento na produção e manutenção do equilíbrio ambiental da microbacia. Palavras-chave: manejo e conservação do solo; microbacias; Sistema de Plantio Direto.
Revista Sociedade Natureza, Nov 3, 2009
The environmental planning in hydrographic micro basins may minimize the incidence of environment... more The environmental planning in hydrographic micro basins may minimize the incidence of environmental impacts as consequence of the human indiscriminate action. The hydrographic basin is worldly recognized as the best unit for handling natural resources. Thus, a methodology for diagnosis of the real situation of natural resources, in a basin, turns to be a necessary tool for the preservation and management of these resources. The identification of the different kinds of predominant vegetables informs, chiefly, about the level of soil protection, since the vegetation is responsible for the protection against the impacts of the raindrops (splash), by the reduction of the speed of surface outflow (runoff), through the increasing of the land ruggedness and greater soil structure constitution that may offer greater resistance to the action of the erosive processes. Besides, the collected data about the covering vegetation generally comes along with the information about the current use of the soil, since they both are strictly related. Several authors have pointed out the importance of geo morphological mappings of environmental planning projects. The use of the cartography and geo morphological information aim to represent the physiography of the landscape,
Anais da Academia Brasileira de Ciências
Retaining sugarcane straw over the soil after harvesting can improve soil structure and increase ... more Retaining sugarcane straw over the soil after harvesting can improve soil structure and increase soil carbon stabilization, mainly in macroaggregates. We evaluated the carbon content in the aggregate classes in areas under burn and no-burn (adopted for five years) sugarcane management systems, focusing on the superficial layer (0.00-0.20 m). The experiment was carried in an Oxisol and the treatments consisted in burnt sugarcane, manual harvest; burnt sugarcane, mechanized harvest; and no-burn, mechanized harvest. The retention of sugarcane straw on the soil surface is justified by the increase in carbon content and carbon stock in the surface layer (0.00-0.20 m) by restructuring of the soil, even though it cannot match the structure of the soil under native forest. Our results suggest that in no-burn management the carbon not occluded inside aggregates was important to increase carbon stabilization in soil and that more attention should be given to macroaggregates 2.00-8.00 mm present in this management system, that showed higher carbon content and was responsible for increase of the geometric and weight diameter, increasing the erosion resistance in the long term in relation to burn systems.
Semina: Ciências Agrárias, 2015
Remote sensing and geographic information systems (GIS) with applied digital image-processing (DI... more Remote sensing and geographic information systems (GIS) with applied digital image-processing (DIP) techniques are essential tools for maintaining land-use records over time. The sugar-ethanol industry has increased over the last 30 years in areas of the Paranapanema Valley in the Western São Paulo Plateau, which is considered one of the last major regions of São Paulo State, Brazil with soil, climate, and relief favorable for expanding sugarcane production. However, there is still no detailed study on changes in land-use and land occupation in the Capivara River basin. In this context, this study aimed to evaluate the expanding land-use toward sugarcane crop production throughout the middle course of the Capivara River basin, southwestern São Paulo, Brazil between 1970 and 2010 using remote sensing. Thus, thematic maps referring to soil types and the land-use of the area were organized using GIS tools, and the cartographic data were used to prepare maps with ArcMap 9.3 software. Th...
Revista Brasileira de Ciência do Solo, 2010
This study had the purpose of evaluating the effects of two management types of sugarcane: harves... more This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40-55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned) management system were closest to those of the soil under native forest. cana picada, crua), sobre propriedades físicas do solo. Os dados foram comparados com os resultados do mesmo solo sob mata nativa. O delineamento utilizado foi o inteiramente casualizado, com três tratamentos e 20 repetições. Foram determinadas a matéria orgânica, estabilidade de agregados, densidade e porosidade do solo, na profundidade de 0-0,20 m, e a resistência do solo à penetração. Após 15 anos de cultivo, constatou-se alteração do solo no sistema CCQ, evidenciada pela diminuição do diâmetro médio ponderado dos agregados estáveis em água e pelo aumento da densidade do solo. Foram também detectadas alterações significativas na porosidade total e distribuição de poros, devido às práticas de manejo nos dois sistemas de colheita. Valores críticos de resistência à penetração foram observados na área de cana mecanizada (CSQ), a 0,40-0,55 m de profundidade, sendo o valor (4,5 MPa) classificado como alto, podendo indicar compactação e restrição ao crescimento radicular. O manejo mecanizado foi o sistema que apresentou características do solo mais próximas às da área de mata nativa. Termos de indexação: Saccharum officinarum, densidade do solo, porosidade, resistência do solo à penetração, estabilidade dos agregados.
Agriculture, Ecosystems & Environment, 2012
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.
This study had the purpose of evaluating the effects of two management types of sugarcane: harves... more This study had the purpose of evaluating the effects of two management types of sugarcane: harvesting of burnt cane (BCH) and mechanized harvesting of unburnt green cane (MCH), on some soil physical properties of a dystrophic Rhodic Haplustox. The data were then compared with results for the same soil type under native forest. A completely randomized design was used, with three treatments and 20 replications. The following characteristics were determined: organic matter, aggregate stability, soil bulk density, and porosity at depths of 0-0.20 m and soil penetration resistance. After 15 years of cultivation, there were some alterations in the soil under cane burnt before harvesting, evidenced by a drop in the weighted average diameter of stable aggregates in water and increased soil bulk density. Significant changes were also detected in total porosity and pore distribution under both harvesting systems. Critical values for penetration resistance were observed in the area under mechanized sugar cane harvesting, with a value of 4.5 MPa in the 40-55 cm layer. This value is considered high and could indicate compaction and restriction of root growth. Soil properties under the green cane (unburned) management system were closest to those of the soil under native forest. cana picada, crua), sobre propriedades físicas do solo. Os dados foram comparados com os resultados do mesmo solo sob mata nativa. O delineamento utilizado foi o inteiramente casualizado, com três tratamentos e 20 repetições. Foram determinadas a matéria orgânica, estabilidade de agregados, densidade e porosidade do solo, na profundidade de 0-0,20 m, e a resistência do solo à penetração. Após 15 anos de cultivo, constatou-se alteração do solo no sistema CCQ, evidenciada pela diminuição do diâmetro médio ponderado dos agregados estáveis em água e pelo aumento da densidade do solo. Foram também detectadas alterações significativas na porosidade total e distribuição de poros, devido às práticas de manejo nos dois sistemas de colheita. Valores críticos de resistência à penetração foram observados na área de cana mecanizada (CSQ), a 0,40-0,55 m de profundidade, sendo o valor (4,5 MPa) classificado como alto, podendo indicar compactação e restrição ao crescimento radicular. O manejo mecanizado foi o sistema que apresentou características do solo mais próximas às da área de mata nativa. Termos de indexação: Saccharum officinarum, densidade do solo, porosidade, resistência do solo à penetração, estabilidade dos agregados.
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Papers by Walquiria Machado