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| Registros recuperados: 10 | |
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| Tiecher,Tales; Pias,Osmar Henrique de Castro; Bayer,Cimélio; Martins,Amanda Posselt; Denardin,Luiz Gustavo de Oliveira; Anghinoni,Ibanor. |
| ABSTRACT The use of gypsum to improve the root environment in tropical soils in the southeastern and central-western regions of Brazil is a widespread practice with well-established recommendation criteria. However, only recently gypsum began to be used on subtropical soils in South of Brazil, so available knowledge of its effect on crop yield is incipient and mainly for soils under no-till (NT) systems. Avaiable studies span a wide range of responses, from a substantial increase to a slight reduction in crop yield. Also, the specific conditions leading to a favorable effect of gypsum application on crop yield are yet to be accurately identified. The primary objectives of this study were to examine previously reported results to assess the likelihood of a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphogypsum; Aluminum saturation; Subsurface acidity; Base saturation. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100505 |
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| Michalovicz,Leandro; Müller,Marcelo Marques Lopes; Foloni,José Salvador Simoneti; Kawakami,Jackson; Nascimento,Ronaldo do; Kramer,Luiz Fernando Machado. |
| Annual crop yield and nutrition have shown differentiated responses to modifications in soil chemical properties brought about by gypsum application. The aim of this study was to evaluate the effect of gypsum application rates on the chemical properties of a Latossolo Bruno (Clayey Oxisol), as well as on the nutrition and yield of a maize-barley succession under no-till. The experiment was set up in November 2009 in Guarapuava, Parana, Brazil, applying gypsum rates of 0.0, 1.5, 3.0, 4.5, and 6.0 Mg ha-1 to the soil surface upon sowing maize, with crop succession of barley. Gypsum application decreased the levels of Al3+ and Mg2+ in the 0.0-0.1 m layer and increased soil pH in the layers from 0.2-0.6 m depth. Gypsum application has increased the levels of... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphogypsum; Calcium saturation; Sulfur; Zea mays; Hordeum vulgare. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832014000500015 |
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| Müller,Marcelo Marques Lopes; Tormena,Cassio Antônio; Genú,Aline Marques; Kramer,Luiz Fernando Machado; Michalovicz,Leandro; Caires,Eduardo Fávero. |
| Gypsum application may enhance the soil quality for plants in terms of soil chemical and physical properties. The objective of this study was to evaluate the effects of gypsum application on the structural quality of a no-tillage Red Latosol. The experiment was initiated in September 2005 in Guarapuava-PR, with gypsum applications of 0; 4; 8; and 12 Mg ha-1 on the soil surface. In November 2009, two soil blocks were sampled from the 0-0.3 m layer for visual evaluation of the soil structure quality (Sq) and to determine the aggregate-tensile strength (ATS). Soil penetration resistance (PR) and gravimetric moisture (H%) of the 0-0.300 m layer were evaluated, and soil cores were collected (layers 0.000-0.075 and 0.075-0.150 m), to determine soil bulk density... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phosphogypsum; Soil physics; Visual score; Aggregation forces. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832012000300030 |
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| Guimarães,Alaine Margarete; Caires,Eduardo Fávero; Silva,Karine Sato da; Rocha,José Carlos Ferreira da. |
| Chemical stratification occurs under no-till systems, including pH, considering that higher levels are formed from the soil surface towards the deeper layers. The subsoil acidity is a limiting factor of the yield. Gypsum has been suggested when subsoil acidity limits the crops root growth, i.e., when the calcium (Ca) level is low and/or the aluminum (Al) level is toxic in the subsoil layers. However, there are doubts about the more efficient methods to estimate the gypsum requirement. This study was carried out to develop numerical models to estimate the gypsum requirement in soils under no-till system by the use of Machine Learning techniques. Computational analyses of the dataset were made applying the M5'Rules algorithm, based on regression models. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rule induction; Calcium; Aluminum; Subsoil acidity; Phosphogypsum. |
| Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902015000200250 |
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| Prochnow,L.I.; Kiehl,J.C.; Pismel,F.S.; Corrente,J.E.. |
| With the purpose of evaluating the effectiveness of phosphogypsum and simple superphosphate in controlling ammonia losses by volatilization during the process of manure composting, an experiment was carried out in closed flasks of 1.6 liter, in which different rates (50, 100, 150 and 200 kg.t-1) of phosphogypsum and simple superphosphate were mixed with a substrate composed of equal amounts (on weight basis) of fresh chicken manure and cattle manure. Ammonia lost by volatilization was determined after 7, 14, 21, 28 and 35 days by trapping the gas in sulfuric acid solution placed in a small glass vial which, in turn, was maintained inside the volatilization flask The remaining acid after the exposure to ammonia was determined by titration with 0.025N NaOH.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonia losses; Phosphogypsum; Simple superphosphate; Manure composting. |
| Ano: 1995 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90161995000200024 |
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| Caires,Eduardo Fávero; Maschietto,Evandro Henrique Gonçalves; Garbuio,Fernando José; Churka,Susana; Joris,Hélio Antonio Wood. |
| The conditions in which a favorable response to a gypsum application can be expected on crop yields are not clear. A 3-year field trial was carried out to evaluate the effects of gypsum application on soil chemical attributes and nutrition and yield of corn (Zea mays L.) and soybean (Glycine max L. Merrill) on a clayey Typic Hapludox of high fertility and low acidity under no-till in Guarapuava, Parana State, Brazil. Treatments were arranged in a randomized complete block design with four replications, and consisted of gypsum application on the soil surface at 4, 8, and 12 Mg ha-1. Gypsum application increased the P content in the soil most superficial layer (0.0 - 0.1 m) and also the exchangeable Ca and S-SO4(2-) contents and the Ca/Mg ratio in the soil... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zea mays; Glycine max; Brazil; Phosphogypsum; Calcium; Sulfur. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162011000200011 |
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| Registros recuperados: 10 | |
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