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| Franco,Henrique Coutinho Junqueira; Pimenta,Maria Teresa Borges; Carvalho,João Luís Nunes; Magalhães,Paulo Sérgio Graziano; Rossell,Carlos Eduardo Vaz; Braunbeck,Oscar Antonio; Vitti,André Cesar; Kölln,Oriel Tiago; Rossi Neto,João. |
| Due to new possibilities for using sugarcane (Saccharum spp.) trash for electricity generation, and the production of 2nd generation ethanol and others chemicals, the interest for its recovery has increased. However, the question of how much trash can be removed from sugarcane field still needs to be clarified. This study evaluated the amount of dry matter, nutrients content, structural compounds and efficiency of the enzymatic hydrolysis of the hydrothermal pretreated materials for tops and dry leaves in samples from sugarcane varieties. Tops and dry leaves present differences in nutrients content and moisture. Therefore, the amount of trash to be collected should not be simply based on percentages, but also should take into account the different... |
| Tipo: Info:eu-repo/semantics/article |
Palabras clave: Saccharum spp.; Enzymatic hydrolysis; Sugarcane crop residues. |
| Año: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000500004 |
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| Segnini,Aline; Carvalho,João Luís Nunes; Bolonhezi,Denizart; Milori,Débora Marcondes Bastos Pereira; Silva,Wilson Tadeu Lopes da; Simões,Marcelo Luiz; Cantarella,Heitor; Maria,Isabella C. de; Martin-Neto,Ladislau. |
| The maintenance of sugarcane (Saccharum spp.) straw on a soil surface increases the soil carbon (C) stocks, but at lower rates than expected. This fact is probably associated with the soil management adopted during sugarcane replanting. This study aimed to assess the impact on soil C stocks and the humification index of soil organic matter (SOM) of adopting no-tillage (NT) and conventional tillage (CT) for sugarcane replanting. A greater C content and stock was observed in the NT area, but only in the 0-5 cm soil layer (p < 0.05). Greater soil C stock (0-60 cm) was found in soil under NT, when compared to CT and the baseline. While C stock of 116 Mg ha-1 was found in the baseline area, in areas under CT and NT systems the values ranged from 120 to 127... |
| Tipo: Info:eu-repo/semantics/article |
Palabras clave: Laser-Induced Fluorescence Spectroscopy; Sugarcane replanting; Crop residues; No-tillage; Soil organic matter. |
| Año: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000500006 |
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| Farhate,Camila Viana Vieira; Souza,Zigomar Menezes de; Oliveira,Stanley Robson de Medeiros; Carvalho,João Luís Nunes; Scala Júnior,Newton La; Santos,Ana Paula Guimarães. |
| ABSTRACT: The use of data mining is a promising alternative to predict soil respiration from correlated variables. Our objective was to build a model using variable selection and decision tree induction to predict different levels of soil respiration, taking into account physical, chemical and microbiological variables of soil as well as precipitation in renewal of sugarcane areas. The original dataset was composed of 19 variables (18 independent variables and one dependent (or response) variable). The variable-target refers to soil respiration as the target classification. Due to a large number of variables, a procedure for variable selection was conducted to remove those with low correlation with the variable-target. For that purpose, four approaches of... |
| Tipo: Info:eu-repo/semantics/article |
Palabras clave: Soil CO2 emission; Data mining; Variable selection; Soil temperature; Soil organic matter. |
| Año: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000300216 |
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| Carvalho,João Luís Nunes; Carlos Eduardo Pelegrino,Cerri; Feigl,Brigitte Josefine; Píccolo,Marisa de Cássia; Godinho,Vicente de Paula; Herpin,Uwe; Cerri,Carlos Clemente. |
| Land use change and land management practices can modify soil carbon (C) dynamics and soil fertility. This study evaluated the effect of tillage systems (no-tillage - NT and conventional tillage - CT) on soil C and nutrient stocks in an Oxisol from an Amazonian cerrado following land use change. The study also identified relationships between these stocks and other soil attributes. Carbon, P, K, Ca and Mg stocks, adjusted to the equivalent soil mass in the cerrado (CE), were higher under NT. After adoption of all but one of the NT treatments, C stocks were higher than they were in the other areas we considered. Correlations between C and nutrient stocks showed positive correlations with Ca and Mg under NT due to continuous liming, higher crop residue... |
| Tipo: Info:eu-repo/semantics/article |
Palabras clave: Oxisol; No-tillage; Conventional tillage; Nutrient stock. |
| Año: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162009000200013 |
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| Carvalho,João Luís Nunes; Otto,Rafael; Franco,Henrique Coutinho Junqueira; Trivelin,Paulo Cesar Ocheuze. |
| Sugarcane (Saccharum spp.) crops provide carbon (C) for soil through straw and root system decomposition. Recently, however, sugarcane producers are considering straw to be removed for electricity or second generation ethanol production. To elucidate the role of straw and root system on the carbon supply into the soil, the biomass inputs from sugarcane straw (tops and dry leaves) and from root system (rhizomes and roots) were quantified, and its contribution to provide C to the soil was estimated. Three trials were carried out in the State of Sao Paulo, Brazil, from 2006 to 2009. All sites were cultivated with the variety SP81 3250 under the green sugarcane harvest. Yearly, post-harvest sugarcane residues (tops, dry leaves, roots and rhizomes) were... |
| Tipo: Info:eu-repo/semantics/article |
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| Año: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000500008 |
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| Araújo,Alexandre Romeiro de; Carvalho,João Luís Nunes; Guilherme,Luiz Roberto Guimarães; Curi,Nilton; Marques,João José. |
| No sistema de plantio convencional, a prática anual de revolvimento do solo provoca alterações nas propriedades físicas, como diminuição da porosidade, modificação da estabilidade de agregados e destruição dos canais deixados pelo sistema radicular. No sistema de plantio direto, não há revolvimento do solo. Portanto, a aplicação de calcário, assim como de N, deve ser feita em superfície, em razão da impossibilidade de sua aplicação em profundidade. Objetivou-se com este trabalho estudar a movimentação de NO- e NH+ em colunas de solo indeformado, com e sem aplicação de calcário. Conduzido em casa-de-vegetação, utilizaram-se tubos de PVC com 0,2 m de diâmetro e 0,2 m de comprimento. As amostras de um Latossolo Vermelho Distrófico típico de textura muito... |
| Tipo: Info:eu-repo/semantics/article |
Palabras clave: Lixiviação; Nitrogênio; Colunas de solo. |
| Año: 2004 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542004000300008 |
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| Cardoso,Terezinha de Fátima; Cavalett,Otávio; Chagas,Mateus Ferreira; Morais,Edvaldo Rodrigo de; Carvalho,João Luís Nunes; Franco,Henrique Coutinho Junqueira; Galdos,Marcelo Valadares; Scarpare,Fábio Vale; Braunbeck,Oscar Antonio; Cortez,Luis Augusto Barbosa; Bonomi,Antonio. |
| Mechanized sugarcane (Saccharum spp.) harvest without burning has been increasingly adopted in Brazil, increasing trash availability on the field. This study aims at showing the importance of using an integrated framework tool to assess technical and economic impacts of integral harvesting and baling trash recovery strategies and different recovery rates as well as its implications in the sugarcane production, transport and processing stages. Trash recovery using baling system presents higher costs per unit of mass of recovered trash in comparison to system in which trash is harvested and transported with sugarcane stalks (integral harvesting system). However, the integrated agricultural and industrial assessment showed that recovering trash using baling... |
| Tipo: Info:eu-repo/semantics/article |
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| Año: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000500010 |
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