ABSTRACT The traditional paradigm of education, although outdated, still supports Soil Educational procedures in several Brazilian universities. However, the strategic documents of these institutions (Institutional Development Plan-IDP, Institutional Political Project-IPP and Pedagogical Projects of Courses-PPC's) support a critical vision of education, which converges with the emancipatory paradigm and with the purpose of Soil Education (SE), which is the formation and transformation of subjects for conscious actions in reality. To overcome this problem, we propose educational procedures guided by emancipatory principles for two disciplines related to the subject of soils in Higher Education (HE) in a traditional paradigm structure, with the objective of meeting the conception of education supported in the strategic documents of a Brazilian public university and achieving the purpose of SE. A bibliographical research and documental analysis of the strategic documents were carried out to form a theoretical and methodological base. In addition, emancipatory principles were considered in the elements that made up the educational procedures in SE. The proposal was analyzed and discussed based on the behavior of these principles in the structure of the disciplines. To verify how the proposal articulates with the conception of education defended by the university, the analysis started from the didactic-pedagogical aspects expressed in the IDP, IPP, PPC's and Teaching Plans of the disciplines involved in the research. We emphasize that it was possible to propose and apply educational procedures on soils with emancipatory principles within a traditional paradigm structure. Some principles were considered in essence, while others could not be considered or were only partially considered, showing that the traditional paradigm limits principles that go against its foundations. The proposal responded more to the concept of critical education defended in the strategic documents than the Soil Educational procedures with traditional principles elaborated and used by professors, since the proposal considered the student’s protagonism, the constitution of their autonomy, knowledge as relational, research as an educational principle, interculturality and procedural and continuous evaluation. On the other hand, procedures with traditional principles considered students as passive subjects, knowledge was seen as fragmented and their approach was made in an authoritarian way, disregarding students’ knowledge and the evaluation was quantitative. Furthermore, the convergence of educational intentionality between Education in Soils and education with emancipatory principles allows us to state that the emancipatory paradigm was an alternative to achieve the educational and formative purpose in educational processes on soils.

ABSTRACT Soil Education aims to give individuals a transforming formative process for conscious actions related to the soil in their life experiences in and with the world. As such, the educational methodologies addressing soil-related contents should be in dialogue with the purpose of this educational process. On the perspective of education for social transformation, it is recommended that professors of Higher Education avoid from pedagogical actions with traditional approaches, and start using other strategies and methodologies centered on students and their context. With the challenge of addressing the implementation of emancipatory principles in educational procedures within the disciplinary structure of a traditional paradigm of education and achieving the aim of Soil Education, we put forward the Alternative Methodology of Problem Cases (AMPC), which was shaped up from two methodologies with constructivist principles, P roblem-Based Learning (PBL) and Team-Based Learning (TBL). This methodology is divided into three phases (preparation, application, and reflection), which are in turn divided into seven steps that complement each other (recovery of socio-historical knowing and knowledge; study of the themes; problem case resolution; team guidance; individual activity report; and individual and collective feedback). In addition, the steps contain individual and team assignments, which revolve around the resolution of problem cases related to the future profession. The AMPC is different from PBL and TBL as the former is grounded on emancipatory principles that facilitate the development of educational processes that value the socio-historical knowing and knowledge of individuals and enable the development of students’ autonomy, creativity, critical thinking, and awareness for actions in real life. The challenges through which individuals can develop relational, complex, and critical thinking, apply them to professional life situations, confront and reframe their knowledge and knowing, as well as create solutions and plan future scenarios with the practice of solving problem cases about soils consist in the capacity of AMPC to be efficient to soil learning.

ABSTRACT The teacher’s formative process is developed by a critical reflective response to the paths of life, the profession, and its practices. The teacher’s formative process analysis should consider the process’s objectives (theoretical, practical, and emancipatory), and the dimensions that make up the teacher (person, practices, and profession). As a result, this study aims to introduce the elements that outline the categories stemming from the relationship matrix between the objectives and the dimensions, and use them to analyze a formative process in Soil Education assessed using Formative (Auto)biographical Narratives. The research subjects were 61 teachers active in the Public Education System in the cities of Campo Largo and Curitiba, state of Paraná, Brazil, who took part in the formative process known as Soil Program for Teachers within the Soil at School Project from the Federal University of Paraná, held in 2018. Data collection was performed through written narratives given in response to three groups of open-ended questions, which aimed to encourage teachers to think deep. We performed the Content Analysis in the narratives while differentiating expressions associated with the elements in each category, and, consequently, the frequency of the expressions was recorded. As for the Theoretical Objectives within the analysis of the Program, in which the teacher is the study object, we found that the teachers built and rebuilt knowledge and expertise about the soil while drawing on the relationship between the formative conceptual approaches and the recollection of their professional and personal experiences through the Narratives. Within the Practical Objectives, in which self-formation is analyzed, the Narrative influenced a critical and reflective perspective about the person, the practice, and the profession, while driving teachers to their self-formation and creating their professional identity. As for the analysis of the Emancipatory Objectives, which demonstrate the change of reality, the teacher’s transformation was seen in their change of attitude and practices, as well as in their intent to get involved with the school. We concluded that the elements proposed to outline the nine categories were effective to analyze the formative process in Soil Education, by taking into account, in an integral way, the Objectives of the analysis and the Dimensions that make up the teacher while in his/her formative process. We would also like to point out that the Narratives were an important instrument for continuous education in Soil Education.

Resumo O texto a seguir dialoga sobre a experiência vivenciada e integrada entre estudantes de uma turma do Curso de Licenciatura em Ciências e de uma turma do 9° ano do ensino fundamental no litoral paranaense. Compreendendo a importância de buscar a ruptura epistemológica com o paradigma educacional dominante, buscou-se por novos sentidos e maneiras de fazer e fazer-se na docência. Em docência compartilhada, via aprendizagem por projetos e, especialmente, apoiados na pedagogia freireana, os autores apresentam suas percepções sobre os processos de mediação na formação de professores e na formação humana. Apontam como principais aprendizados: a necessidade de intervenção nos espaços formativos; o reconhecimento do contexto local para a ressignificação de conceitos e valores; a garantia de espaços de escuta e de fala; e, sobretudo, o cuidado afetivo com o outro.

Abstract The following text dialogues with the integrated and lived experience between students of a Bachelor of Science Degree course and students of the 9th grade from a middle school in Paraná state coast, Brazil. Understanding the importance of seeking for the epistemological break with the dominant educational paradigm, new meanings were sought, ways of doing and being in academic teaching. In shared teaching, through learning projects, specially based on Paulo Freire's pedagogy, the authors present their perceptions of mediation processes in teacher education and human formation. The main indicated sources of learning are the need for intervention in the formative spaces; the recognition of the local context to reframe concepts and values; the guarantee of listening and speech spaces and, above all, the emotional care for the other.

Hidróxidos duplos lamelares (HDL) são intercaladores potenciais aniônicos. Com o objetivo de obter fertilizantes de liberação lenta de nitrato, foram sintetizados HDL com a fórmula geral [M2+1-xM3+x(OH)2]x-(NO3)x.yH2O, em que M2+ = Mg2+ e M3+ = Al3+ e, ou, Fe3+, utilizando-se o método de coprecipitação a pH alcalino constante. Medidas de difração de raios-X evidenciaram que a cristalinidade aumenta com o acréscimo do valor de pH e da razão molar M2+/M3+. As medidas de FTIR apresentaram bandas características de nitrato livre no espaço interlamelar, além de pequena contaminação de íons carbonato. Medidas de TGA/DTA possibilitaram a confirmação das composições e dos teores de íons de nitrato intercalados. As curvas de liberação de nitrato demonstraram dois comportamentos de liberação complementar, um inicial rápido (A) e um lento gradativo (D), sendo, este último, relacionado à orientação planar do íon nitrato intercalado. Os materiais sintetizados e investigados neste trabalho apontaram grande potencial para serem utilizados como matrizes para fertilizantes de liberação lenta de nitrato.

Layered double hydroxides (LDHs) are potential anionic intercalators. To obtain nitrate slow-release fertilizers, LDHs with the general formula [M2+1-xM3+x(OH)2]x-(NO3)x.yH2O (where M2+ = Mg2+ and M3+ = Al3+ and/or Fe3+) were synthesized by the method of co-precipitation at constant alkaline pH. The X-ray diffraction (XRD) measurements showed that crystallinity increases with the pH value and with the M2+/M3+ molar ratio. The FTIR measurements showed characteristic bands of free nitrate in the interlayer, as well as minor carbonate ion contamination. The compositions and concentrations of intercalated nitrate ions were confirmed by TGA/DTA measurements. The nitrate release curves showed two patterns of complementary release - fast initial release (A) and slow gradual release (D). The latter is related to the planar orientation of the intercalated nitrate ion. The synthesized materials investigated in this study proved to be highly promising as matrices for nitrate slow-release fertilizers.

Diante do extensivo uso de fertilizantes nitrogenados na agricultura e elevado potencial de lixiviação do nitrato, há uma demanda por fertilizantes de liberação lenta ou controlada. Os hidróxidos duplos lamelares (HDLs) sintéticos reúnem características que os qualifica para o uso como matrizes para fertilizantes de liberação lenta de íons nitrato. Os objetivos deste trabalho foram focados na síntese, caracterização e investigação do processo de liberação lenta de nitrato em um HDL contendo íons Mg2+ e Al3+ em sua estrutura. O HDL com a fórmula Mg0,83Al0,17(OH)2(NO3)0,17.0,56H2O foi sintetizado pelo método de coprecipitação em pH alcalino constante, separado por centrifugação e seco em estufa a vácuo. As análises de difração de raios-X, de espectroscopia vibracional na região do infravermelho com transformada Fourier e as análises térmicas comprovam a obtenção do composto contendo o íon nitrato hidratado intercalado, além da fórmula proposta. O composto foi submetido a testes de liberação de nitrato em solução de NaHCO3 tamponado a pH 6,5 e em água destilada. As curvas obtidas evidenciaram dois eventos complementares de liberação de nitrato, um evento inicial rápido e um outro lento e gradativo. O composto investigado neste trabalho demonstrou potencial para ser utilizado como matriz para fertilizante de liberação lenta de nitrato.

Due to the extensive use of nitrogen fertilizers in the agriculture e due to the elevate potential of nitrate leaching, there is a great demand for slow or controlled release fertilizers. Synthetic layered double hydroxides (HDLs) combine the characteristic that qualifies them to be used as matrixes for nitrate slow release fertilizers. The objectives of the present work are focused in the synthesis, characterization and investigation of the slow release of nitrate process in one structure of a HDL containing ions Mg2+ and Al3+ in its structure. The HDL with the formula Mg0,83Al0,17(OH)2(NO3)0,17.0,56H2O was synthesized by the co-precipitation method at constant alkaline pH, isolated by centrifugation and dried in an vacuum oven. Measurements of X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR) and thermal analysis (TGA/DTA) confirmed the obtaining of the compound containing the intercalated hydrated nitrate anions and the proposed formula. The compound was tested for release nitrate NaHCO3 solution buffered to pH 6.5, and distilled water. The representative curves demonstrated two complementary behaviors nitrate release a fast initial and a slow gradual. The compound investigated in this study demonstrates the potential to be used as a matrix for slow release fertilizer nitrate. The compound was submitted to the nitrate release tests using a NaHCO3 solution buffered at pH 6.5 and in distilled water. The obtained curves have shown two complementary events of nitrate release, one fast initial event and another slow and gradual. The compound investigated in the present work has shown a potential to be used as matrix for nitrate slow release fertilizers.

A acidez do solo e variáveis associadas são muito importantes nos manejos dos solos, especialmente nas regiões tropicais e subtropicais. Com o objetivo de estudar algumas variáveis da acidez do solo e verificar a influência da mineralogia da fração argila sobre a relação entre pH em CaCl2 e grau de saturação por bases (V), amostraram-se os horizontes B e C de diferentes classes de solo no Estado do Paraná: Latossolo Bruno ácrico húmico (LBw-1), Latossolo Bruno distrófico húmico (LBw-2), Latossolo Vermelho distroférrico húmico (LVdf), Cambissolo Háplico alumínico típico (CXa) e Cambissolo Húmico distroférrico típico (CHd). A fração argila foi estudada por difratometria de raios X, análise termodiferencial, análise termogravimétrica e análises químicas. As amostras de solo foram incubadas por 60 dias, após terem recebido doses crescentes de óxido de cálcio, para atingir valores preestabelecidos do grau de saturação por bases (natural, 25, 45, 60, 70, 125 e 150 %). Em seguida, determinaram-se os teores de cátions trocáveis e os valores de pH em H2O e solução de CaCl2 1 mol L-1. Os solos apresentaram o seguinte comportamento quanto à mineralogia da fração argila: mais esmectítico/vermiculítico - CXa; mais oxídico, principalmente óxidos de Fe - LVdf e óxidos de Al - LBw1; mais caulinítico, com menores teores de óxidos de Fe e Al - CHd e LBw2. Essa diversidade mineralógica foi determinante na relação pH em CaCl2 e grau de saturação por bases (V) dos solos. As curvas que mostraram essa relação foram não lineares, o que significa poder tamponante diferenciado ao longo da faixa de pH em CaCl2 estudada; formato convexo dos solos mais oxídicos e côncavo dos solos cauliníticos e com argila 2:1. O formato convexo das curvas foi conseqüência da formação de cargas negativas e dissociação de H+ preferencialmente a valores elevados de pH em CaCl2 (acima de 5), devido à menor acidez (PCZ mais alto) dos radicais Fe-OH e Al-OH. O formato côncavo foi atribuído a cargas permanentes e a maior dissociação de H+ a valores menores de pH em CaCl2 (abaixo de pH 5), uma vez que o radical Si-OH é considerado um ácido forte (PCZ baixo). Para um mesmo pH em CaCl2 verificou-se a seguinte seqüência nos valores de V em função da mineralogia da fração argila: solos com predomínio de óxidos de Fe e Al < solos com predomínio de caulinita < solos cauliníticos com minerais 2:1.

The soil acidity and associated variables are very important on soil management, especially at tropical and subtropical regions. In order to study some soil acidity variables and verify the influence of clay mineralogy on the relationship between pH and base saturation degree (V%), soil samples were collected from B and C horizons of different soil classes in Paraná State: Acric Red-Yellow Latossol (LBw-1), Dystric Red-Yellow Latossol (LBw-2), Dusky Red Latosol (LVdf), Alumic Cambisol (CXa) and Dystric Cambisol (CHd). The clay fraction was studied by X-ray diffraction, thermal differential, thermal gravimetric and chemical analysis. Soil samples were incubated for 60 days, after treatment with increasing calcium oxide rates, in order to reach determined degrees of base saturation (native, 25, 45, 60, 70, 125, and 150 %). Then, the exchangeable base contents and pH in H2O and CaCl2 0.01 mol L-1 were determined. Results indicated the following clay mineralogy composition in the soils: smectite/vermiculite - CXa; Fe oxide - LVdf, Al oxide - LBw1; Kaolinite with low contents of Fe and Al oxide - CHd and LBw2. This diversity in clay mineralogy was important for the CaCl2 pH with base saturation (V%) relationship. The curves show that this relationship is non-linear, meaning that buffer capacity varies in the evaluated pH range. A convex curve represents a more oxidic soil, while a concave curve represents a kaolinitic soil with 2:1 clay. The convex curve shape was result of the negative charge formation and preferential H+ dissociation at high pH (above pH 5), since Fe-OH and Al-OH act as weak acid (high PZC). The concave shape was attributed to the presence of permanent charges and high dissociation capacity of H+ at low pH (below pH 5), since the Si-OH acts as strong acid (low PZC). For the same pH in CaCl2 the following sequence of V % values were observed as a function of clay mineralogy: soil with predominance of Fe and Al oxide < soil with predominance of Kaolinite < soil with predominance of Kaolinite with 2:1 clay.