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| Reis, Daniele Nogueira dos; van Straaten, Peter; Furtini Neto, Antonio Eduardo; Bittar, Sheila Maria Bretas; Curi, Nilton. |
| Knowledge of a rock’s composition allows for inferences regarding several properties, ranging from its physical characteristics to its solubility. This study aimed to evaluate the use of different extractants to solubilize the K present in rocks as a potential source of nutrients and the effects of extractant contact time and temperature on rock solubilization. Samples of two rocks and a mineral concentrated from a granitic rock were treated with ammonium dihydrogen phosphate (NH4(H2PO4)), calcium dihydrogen phosphate (Ca(H2PO4)2), sodium hydroxide (NaOH) and water (control). Sample-extractant treatments were performed using a water bath shaker at temperatures of 25 and 50°C for periods of 3, 7, 10, 20, and 30 days. The amounts of K extracted from rocks... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Minerals; Soluble K; Fertilizers; Powdered rock. |
| Ano: 2016 |
URL: http://periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/28457 |
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| Gomes, Joao Bosco Vasconcellos; Araújo Filho, José Coelho de; Curi, Nilton. |
| Landscapes formed on Barreiras Formation sediments occupy signifi cant area on Brazilian territory. Many of these landscapes have highly intensive agricultural use, dueto favorable climate and topography. The objective of this study was to characterize and to compare soil profi les situated on non-dissected coastal plains from southern Bahia to Alagoas, occurring under natural vegetation (forest) and agricultural use. Seven soil profi leswere analyzed and data from six soil profi les obtained in other works were incorporated. Particle size distribution, organic C (OC), Al, Ca, Mg, Al+H, K, Na, P, Fe, Ti and Si were determined. Clay mineralogy was analyzed by X-ray diffraction. Soil profi les occur on fl at relief, have yellow color, weak small to medium... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cohesive character; Barreiras Formation; Kaolinite Caráter coeso; Formação Barreiras; Caulinita. |
| Ano: 2012 |
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/324 |
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| D’Andrea, Alexandre Fonseca; Silva, Marx Leandro Naves; Freitas, Diego Antonio França de; Curi, Nilton; Silva, Carlos Alberto. |
| Soil is an important compartment of carbon in terrestrial ecosystem, retaining substantial quantity of this element in organic forms, mainly in forest areas. The understanding of the factors that affect the fluxes of soil CO2 is the basic to the reduction of emissions of greenhouse gases to the atmosphere. The objective of this work was to evaluate the patterns of spatial variability of soil CO2 flux in native forest in a very clayey dystroferric Red Latosol (Oxisol), in Lavras city, Minas Gerais state, Brazil. A grid of 32 points was delimited, regularly spaced in 5 m distance, in which the CO2 flux and environmental factors (water evaporation, temperature and soil moisture) and attributes related to fertility (pH, base soil saturation and exchangeable... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Environmental factors; Carbon; Organic matter; Linear correlation. fatores ambientais; Carbono; Matéria orgânica; Correlação linear. |
| Ano: 2010 |
URL: http://pfb.cnpf.embrapa.br/pfb/index.php/pfb/article/view/169 |
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