Abstract The right choice of a university program by young people constitutes a challenge for themselves, their families and society, since their personal development, professional success, values, and community service depend on it. Considering the factors that intervene in this choice are diverse, this work seeks to determine empirically if school self-esteem and motivation degree influences enrolment in a first-preference university program. The sample corresponds to the 2626 students who entered at Universidad de Concepción Campus Chillán, between 2016 and 2021. A binary probit model was used since the dependent variable oscillates between two discrete values. The self-esteem and motivation degree was measured from one of the Personal and Social Development Indexes (IDPS, in Spanish), delivered by the Education Quality Agency dependent of the Chilean Secretaryship of Education, for each high school graduation institution. Control variables such as personal characteristics of both, students and institutions, were added. The results confirm that the higher the school self-esteem and motivation degree, the greater the probability that the student enters the program of his/her first preference. This study confirms the importance of school self-esteem and motivation, also there is still a progress to be made in firming up school programs that put the emphasis on promoting conditions that allow the full development of students, highlighting strengths over weaknesses.

Resumen Para los jóvenes, la elección acertada de un programa universitario constituye un desafío para ellos, su familia y la sociedad, puesto que el desarrollo personal, el éxito profesional, los valores y el servicio a la comunidad dependen de ella. Considerando que los factores que intervienen en esta elección son variados, el estudio buscó determinar, empíricamente, si el grado de autoestima y motivación escolar tiene efecto en la matrícula de un programa universitario, como primera preferencia. La muestra corresponde a los 2626 jóvenes que ingresaron a la Universidad de Concepción, Campus Chillán, en 2016-2021. Se utilizó un modelo probit binario, pues la variable dependiente toma uno de dos valores discretos. El grado de autoestima y motivación se midió a partir de uno de los índices de desarrollo personal y social (IDPS), entregado por la Agencia de Calidad del Ministerio de Educación de Chile para cada establecimiento de egreso de enseñanza media. Se incorporaron variables de control, como las características personales del estudiante y del establecimiento. Los resultados confirman que, cuanto mayor es el índice de autoestima y motivación escolar, mayor es la probabilidad de que el estudiante ingrese al programa de su primera preferencia. Este análisis confirma (1) la importancia de este Indicador y (2) que aún faltan avances para fortalecer programas escolares que pongan el énfasis en propiciar condiciones que permitan el desarrollo integral de los estudiantes, destacando las fortalezas por sobre las debilidades.

Abstract A cyclone occurred off the southern Brazilian coast between 30/06/2020 and 01/07/2020, moving eastwards from land towards offshore. The system was registered in numerical models and in-situ observations (buoy and ship) from the day it started until dissipated. The goal of this work is to use the data collected during this extreme environmental condition in a statistical comparison with the atmospheric operational model Global Forecast System (GFS) and a local implementation of the WAVEWATCH III (WW3) wave model, which used the GFS as one of the inputs, to understand the limitations of these models. Initially, the results showed that the system near the southern Brazilian coast was a strong explosive cyclone according to the Sanders and Gyakum (1980) classification. We found that the GFS and WW3 models exhibited greater errors when compared with the buoy data during the 48 h period of explosive weather conditions, while for the GFS model, the greatest errors around the ship occurred after that period. The WW3 errors may be explained by the difference between the buoy and WW3 gridpoint depth and the GFS errors at this location.

Resumo Ocorreu um ciclone na costa sul do Brasil entre 30/06/2020 e 01/07/2020, movendo-se do continente em direção ao mar. O sistema foi registrado em modelos numéricos e observações in-situ (boia e navio) desde o dia em que se formou até se dissipar. O objetivo deste trabalho é utilizar os dados coletados durante essa condição ambiental extrema em uma comparação estatística com o modelo atmosférico operacional Global Forecast System (GFS) e uma implementação local do modelo de ondas WAVEWATCH III (WW3), que utiliza o GFS como um dos inputs, para entender as limitações desses modelos. Inicialmente, os resultados mostraram que o sistema próximo à costa sul do Brasil era um ciclone explosivo forte de acordo com a classificação de Sanders e Gyakum (1980). Descobrimos que os modelos GFS e WW3 apresentaram maiores erros em comparação com os dados da boia durante o período de 48 horas de condições meteorológicas explosivas, enquanto para o modelo GFS, os maiores erros ao redor do navio ocorreram após esse período. Os erros do WW3 podem ser explicados pela diferença entre a profundidade da boia e o ponto da grade do WW3, e os erros do GFS nessa localização.

ABSTRACT We assessed the impacts of the biological invasion of Azadirachta indica on the quality of plant species native to a Seasonally Dry Tropical Forest. We planted Amburana cearensis, Libidibia ferrea, Mimosa caesalpiniifolia, and Cenostigma pyramidale individuals alone and interacting with the exotic species. We measured their diameters at ground level and heights for four months, calculating their monthly and general average. After this period, seedlings were destroyed to obtain their number of leaves, leaf area, specific leaf area, length and primary root area, wood density, wood dry matter, leaf dry matter, shoot dry matter, primary root dry matter, secondary root dry matter, root system dry matter, and total dry matter. The presence of the exotic species affected the functional characteristics of native species in different ways. We observed negative effects in M. caesalpiniifolia and A. cearensis, positive effects in C. pyramidale, and mixed effects in L. ferrea. In addition, we identified conflicting demands between pairs of characteristics of the interacting species A. cearensis and M. caesalpiniifolia. Based on the results, it is possible to conclude that A. indica decreases the quality of individuals of most native species studied, which may have consequences for their establishment and the local biodiversity.

Resumo A água residuária de suínos (ars) pode impulsionar o crescimento e o desenvolvimento de mudas em várias espécies, pois esse resíduo é rico em nutrientes necessários às plantas. Este estudo testou a hipótese de que mudas de Guazuma ulmifolia cultivadas em substrato à base de lodo suíno apresentam melhor desempenho fisiológico e morfológico. As mudas foram cultivadas em sete substratos: T1 - casca de arroz e vermiculita; T2 - 20% ars; T3 - 40% ars; T4 - 60% ars; T5 - 80% ars; T6 - 100% ars; e T7 - 100% Bioplant®. Foram avaliados a altura (H), diâmetro (D), número de folhas (NF), bem como a razão H para D, índices de clorofila, trocas gasosas, biomassa, razões alométricas, Índice de Qualidade Dickson (IQD), e a porcentagem de mudas mortas. Os dados foram analisados pela análise de variância e as médias comparadas pelo teste de Tukey. Os substratos com a maior porcentagem de lodo suíno promoveram a maior H, D, NF, índices de clorofilas, trocas gasosas, biomassa caulinar e IQD. A maior mortalidade foi obtida no substrato comercial (85%) e casca de arroz carbonizada e vermiculita (37,5%). Pode-se concluir que os substratos com alto teor de lodo de suíno foram os melhores para as mudas de G. ulmifolia.

Abstract Swine wastewater (sw) can boost seedling growth and development in several species as this residue is rich in nutrients required by plants. This study tested the hypothesis that seedlings of Guazuma ulmifolia grown in a substrate based on swine wastewater showed better physiological and morphological performance. The seedlings were cultivated in seven substrates: T1 - rice husk and vermiculite; T2 - 20% sw; T3 - 40% sw; T4 - 60% sw; T5 - 80% sw; T6 - 100% sw; and T7 - 100% Bioplant®. Were evaluated the height (H), diameter (D), number of leaves (NF), as well as the H to D ratio, chlorophyll indices, gas exchange, biomass, allometric ratios, Dickson Quality Index (DQI), and mortality percentage of the seedlings. The data were analyzed by analysis of variance, and the means were compared by Tukey’s test. The substrates with the highest percentage of swine sludge promoted the highest H, D, NF, chlorophyll indices, gas exchange, stem biomass and IQD. The highest mortality was obtained in commercial substrate (85%) and carbonized rice husk and vermiculite (37.5%). Can be concluded that the substrates with high swine wastewater content were better for seedling G. ulmifolia.

Resumo O fósforo (P) é um dos nutrientes mais exigidos pelas plantas, principalmente, na fase inicial, no entanto, existem espécies cujos efeitos de crescimento promovidos pelo fósforo ainda são desconhecidos. Portanto, este trabalho teve como objetivo testar se níveis crescentes de fósforo influenciam no comportamento fisiológico e morfológico e na qualidade das mudas de Guazuma ulmifolia. Para tanto, as mudas foram cultivadas em substrato produzido apenas com LATOSSOLO VERMELHO distrófico, em delineamento inteiramente casualizado e submetido a cinco níveis de fósforo (0, 100, 200, 300 e 400 mg dm-3 ). Aos 120 dias, as avaliações biométricas e fisiológicas foram realizadas, e os índices de clorofila, biomassa, relações alométricas, Índice de Qualidade de Dickson e o teor de fósforo foram determinados. Os dados foram submetidos à análise de variância pelo teste F e posteriormente à análise de regressão e correlação linear de Pearson. A fertilização com fósforo promoveu ganhos significativos (p ? 0,05) à todas as variáveis morfológicas e fisiológicas, exceto para a área foliar específica e relações alométricas. O conteúdo de fósforo foi positivamente correlacionado com todas as variáveis testadas. Com base nos resultados obtidos, conclui-se que as mudas responderam positivamente à fertilização com fósforo. Além disso, a fertilização com fósforo promoveu melhor desempenho fisiológico e morfológico e maior qualidade das mudas.

Abstract Phosphorus (P) is one of the nutrients most required by plants, especially in the initial phase, however, there are species whose growth effects promoted by phosphorus are still unknown. Therefore, this study aimed to test whether increasing levels of phosphorus influence the physiological and morphological behavior and the quality of seedlings of Guazuma ulmifolia. For that purpose, the seedlings were grown in a substrate produced only with Dystrophic RED LATOSOL (Oxisol) under a completely randomized design and subjected to five levels of phosphorus (0, 100, 200, 300, and 400 mg dm-3 ). At 120 days, the biometric and physiological evaluations were performed, and the chlorophyll indices, biomass, allometric relationships, Dickson Quality Index, and the phosphorus content were determined. The data were subjected to analysis of variance by the F-test and subsequently to regression analysis and Pearson’s linear correlation. Phosphorus fertilization promoted significant gains (p ? 0.05) for all variables morphological e physiological, except for the specific leaf area and allometric relationships. The phosphorus content was positively correlated with all tested variables. Based on the results obtained, it is concluded that the seedlings responded positively to phosphorus fertilization. Furthermore, phosphorus fertilization promoted better physiological and morphological performance and higher seedling quality.

Resumo Testamos a hipótese que das espécies estudadas do Semiárido brasileiro, as funcionalmente mais semelhantes com a arbórea exótica Azadirachta indicaseriam mais afetadas na germinação e no desenvolvimento inicial. Inicialmente foi produzido extrato bruto das folhas frescas da exótica em seis diluições. Para cada diluição foram colocadas para germinar 25 sementes, de quatro espécies nativas ( Cenostigma pyramidale, Libidibia ferrea, Mimosa caesalpiniifoliae Amburana cearensis), em placas de Petri com quatro repetições para cada espécie, onde foram avaliados: comprimento da radícula, porcentagem de emergência, índice de velocidade de emergência e tempo médio de emergência. Para avaliar a influência da exótica sobre o desenvolvimento dos indivíduos das espécies estudadas foi realizado um experimento em casa de vegetação. As sementes foram plantadas em 10 baldes de 20 l., sendo cinco baldes para cada espécie nativa isolada e cinco para ela em interação com a espécie exótica. O experimento durou quatro meses, e os atributos funcionais dos indivíduos foram coletados. Das nativas analisadas, de acordo com a análise de agrupamento usando os atributos funcionais das espécies plantadas isoladamente, M. caesalpiniifolia, C. pyramidalee L. ferreaforam funcionalmente mais próximas da exótica. No experimento de germinação notou-se que o extrato afetou apenas o comprimento da raiz, independente da proximidade funcional. Notamos que apenas M. caesalpiniifolia, plantada em interação, teve seu desenvolvimento inicial fortemente inibido. A semelhança funcional entre a exótica e as nativas não influenciou na germinação, mas afetou negativamente o desenvolvimento.

Abstract We tested the hypothesis that of the species studied in the Brazilian Semiarid, the ones most functionally similar to tree Azadirachta indicawould be more affected by this exotic species during germination and early development. At first, we produced a crude extract of A. indica fresh leaves in six different dilutions. We placed 25 seeds of four native species ( Cenostigma pyramidale, Libidibia ferrea, Mimosa caesalpiniifolia, and Amburana cearensis) to germinate in Petri dishes for each dilution, with four replicates for each species. We assessed: radicle length, emergence percentage, emergence speed index, and mean emergence time. We conducted an experiment in a greenhouse to assess how the exotic plant affected the development of individual plants of the studied species. We planted five seeds of each native species alone and five in interaction with the exotic species using ten 20-l buckets. The experiment lasted four months, and the functional attributes of the individuals were collected. Among the native species analyzed, according to the cluster analysis using the functional attributes of the species planted alone, M. caesalpiniifolia, C. pyramidaleand L. ferreawere functionally more similar to the exotic species. In the germination experiment, the extract affected only root length, regardless of the functional similarity. We noticed that only M. caesalpiniifoliahad its early development strongly inhibited when planted in interaction with the exotic species. Although the functional similarity between the exotic and the native species did not influence germination, it negatively affected the development.

Resumen El propósito de este estudio es medir el efecto del anuncio de una emisión de bonos corporativos sobre los retornos accionarios de las empresas que cotizan en la Bolsa de Comercio de Santiago de Chile (BCS). La muestra está compuesta por 29 empresas que realizaron 87 anuncios de emisión de bonos corporativos durante el período 2010-2017. El efecto del anuncio de emisión de bonos sobre el retorno de la acción se mide mediante un estudio de eventos. Esta metodología permite calcular los retornos anormales de las acciones en el día del evento (el día del anuncio) y alrededor de ese día. Los resultados muestran que el retorno anormal promedio en el día del anuncio es negativo (entre -0,09% y -0,03%), pero no significativo. Sin embargo, el retorno anormal promedio en el día siguiente al anuncio es positivo (entre 0,27% y 0,32%) y significativo. El retorno anormal promedio positivo y significativo del día posterior al anuncio sugiere una reacción tardía del mercado. El estudio evidencia que hay un efecto de señalización significativo de los anuncios de emisión de bonos sobre los retornos de las acciones.

Abstract This study measures the announcement effect of corporate bond issuance on stock returns for companies listed on the Santiago de Chile Stock Exchange (BCS). The sample is made up of 29 firms and 87 corporate bond issuance announcements during the 2010-2017 period. The announcement effect of corporate bond issuance on stock return is measured by an event study. This methodology allows to calculate abnormal returns for the days of the event period. The results show that the average abnormal return on the day of the announcement is negative (between -0.09% and -0.03%), but it is not statistically significant. However, the average abnormal return on the day after the announcement is positive (between 0.27% and 0.32%) and has statistical significance. The significant and positive average abnormal return on the day after the announcement suggests a late market reaction. The study shows that there is a significant signaling effect of bond issuance announcements on stock returns.

Resumo Hymenaea stigonocarpa é uma espécie arbórea medicinal usada na recuperação de áreas degradadas. No entanto, pouco se sabe sobre suas exigências nutricionais durante a fase de mudas, principalmente em termos de potássio. Dessa forma, objetivou-se com este trabalho avaliar se doses potássicas promovem alterações morfofisiológicas de mudas Hymenaea stigonocarpa. O delineamento utilizado foi inteiramente ao acaso, com seis doses (0, 50, 100, 150, 200 e 250mg dm-3 de KCl), e quatro repetições. As variáveis avaliadas foram: biométricas, biomassa, fisiológicas e teor de potássio. A espécie apresentou resposta significativa à adubação potássica para os parâmetros fisiológicos e biométricos. Os maiores valores obtidos foram nas doses entre 150 e 200 mg dm-3. E, ainda, observou-se efeito de concentração para o teor de potássio contido nas folhas e caule das mudas de Hymenaea stigonocarpa.

Abstract Hymenaea stigonocarpa is anarboreal medicinal species used in the recovery of degraded areas. However, little is known about its nutritional requirements during the seedling phase, especially concerning to potassium. In this context, the aim of this study was to evaluate if potassium doses promote morphophysiological changes in Hymenaea stigonocarpa seedlings.A completely randomized design, consisting in six KCl doses (0, 50, 100, 150, 200 and 250 mg dm-3 KCl) and four replications was applied. Biometric, biomass, physiological and potassium content variables were assessed. Hymenaea stigonocarpa displayed significant physiological and biometric responses to potassium fertilization, with the highest values observed at doses ranging from 150 to 200 mg dm-3 KCl. Moreover, concentration effects were noted regarding to potassium contents in seedling leaves and stems.

Resumo O presente artigo pretende contribuir para as discussões sobre as formas de ocupação de terras e de direitos de propriedade no Pará de fins do XIX e início do XX. Atentaremos para um estudo de caso de litígio de terras que envolveu pequenos posseiros, suas estratégias de legitimação, concepções e práticas de propriedade tecidas em suas redes de vizinhança. Discutiremos ações que desvelam noções de direito que se defrontam em querelas onde a defesa do acesso à terra vai mobilizar tanto o repertório empírico de práticas costumeiras de apossamento quanto o recurso à formalização jurídica que está sendo (re)construída no período inicial da República. Nossa abordagem se inscreve na vertente da História Social da Propriedade, onde, contrariando uma visão estatista que naturaliza a noção de propriedade a partir de sua formalização institucional e sua consagração como lei, entende que propriedade deve ser pensada no seu fazer-se histórico, como prática, a partir das relações sociais ensejadas pelos sujeitos atuantes. Para tanto, trataremos de um caso de litígio de terras entre duas famílias de posseiros, ocorrido entre 1893 e 1905 na região nordeste do Pará, na localidade do Apeú, área então pertencente à municipalidade de Belém. Nossa abordagem terá como eixo principal a análise de um processo de Ação de Força Velha Espoliativa que atravessa os anos iniciais da República.

Abstract This article intends to contribute to the discussions on the forms of land occupation and property rights in Pará in the late 19th and early 20th centuries. We will look at a case study of land litigation involving small squatters, their legitimation strategies, conceptions and property practices woven into their neighborhood networks. We will discuss actions that unearth notions of law that face the challenges in which the defense of access to the land is mobilizing both the empirical repertoire of customary practices of possession and the recourse to the legal formalization that is being (re)built in the initial period of the Republic. Our approach is part of the social history of property, where, contrary to a statist view that naturalizes the notion of ownership from its institutional formalization and its consecration as law, understands that property should be thought in its history, as a practice, from the social relations that the working subjects have. In order to do that, we will deal with a case of land litigation between two families of squatters that took place between 1893 and 1905 in the northeastern region of Pará, in the locality of Apehú, an area that belongs to the municipality of Belém. Our approach will have as main axis the analysis of a Plundering Old Force Action process that crosses the early years of the Republic.

ABSTRACT We analyzed the effect of managerial ownership, leverage, and managerial discretion on the agency costs of 14,719 Chilean companies. The results of the instrumental variables (IV) regressions indicate that managerial ownership and capital structure have a negative and non-linear effect on agency costs. Managerial ownership concentration is an effective means of internal control over agency costs, discarding the managerial entrenchment effect. The non-linear impact of debt suggests that for high leverage levels, agency costs would increase due to higher bankruptcy costs. Managerial discretion reduces agency costs; however, in firms with low growth opportunities, it increases them. These results have relevant implications for firms’ corporate policy and investors.

Resumen En este artículo se analizan los efectos de la concentración de mercado y diversificación de ingresos sobre la estabilidad financiera de la banca en el ámbito mundial. Usamos el estimador GMM de Arellano y Bover (1995) para una muestra de 206 países entre 1994 y 2015. Los resultados demuestran que la concentración de mercado y la diversificación de ingresos tienen un efecto positivo y no lineal sobre la estabilidad financiera; y negativo y no lineal sobre el riesgo. La no linealidad sugiere que sus efectos se reversan cuando la industria bancaria tiene una elevada concentración y diversificación, observándose una industria menos estable y más riesgosa. La no linealidad establece valores umbrales que son relevantes para el diseño óptimo de políticas financieras y estrategias bancarias.

Abstract This paper analyzes the effects of market concentration and income diversification on the financial stability of the world banking system. It uses the GMM estimator proposed by Arellano and Bover (1995) to study 206 countries between 1994 and 2015. The results show that market concentration and income diversification have a positive and nonlinear effect on financial stability; and a negative and nonlinear effect on bank risk. The nonlinearity shape suggests that the effects are reversed when the banking industry has a higher market concentration and income diversification. In these cases, lower levels of stability and higher risks would characterize the banking industry. Nonlinearity establishes threshold values that are relevant for the empirical discussion oriented to an optimal design of financial policies and banking strategies.

Resumo O objetivo deste estudo foi determinar de que forma as mudas de Guazuma ulmifolia respondem a doses nitrogenadas, tendo como fonte de nitrogênio (N) a ureia. O cultivo das mudas ocorreu em delineamento inteiramente ao acaso, as quais foram submetidas a cinco doses (0, 50, 100, 150 e 200 mg dm-3) de N. Aos 120 dias de cultivo foram realizadas avaliações biométricas, fisiológicas, acúmulo de biomassa, razões alométricas, índice de qualidade de Dickson (IQD), teor, acúmulo e eficiência do uso de N (EUN) na parte aérea das mudas. Os dados foram submetidos a análise de variância e regressão. Além disso, o coeficiente de correlação de Pearson também foi analisado. As doses de N promoveram significativamente (p≤0,05) o aumento do teor de N na parte aérea das mudas. Por outro lado, registrou-se a redução significativa do acúmulo de N, de variáveis fisiológicas, crescimento, biomassa, IQD e EUN, que culminou em correlação negativa com o fornecimento crescente de N. Doses de N muito elevadas, tendo como fonte a ureia, foram prejudiciais para as mudas de Guazuma ulmifolia. As doses entre 20 e 38,8 mg dm-3 de N, de modo geral, foram as que promoveram os melhores resultados.

Abstract The aim of this study was to determine how Guazuma ulmifolia seedlings respond to nitrogen doses, with urea as a nitrogen source (N). The seedlings were cultivated in a completely randomized design, which were subjected to five doses (0, 50, 100, 150 and 200 mg dm-3) of N. At 120 days of cultivation, biometric, physiological, biomass accumulation, allometric ratios, Dickson's quality index (IQD), content, accumulation and N efficiency use (NUE) in the aerial part of the seedlings. The data were submitted to analysis of variance and regression. In addition, Pearson's correlation coefficient was also analyzed. The N doses significantly promoted (p≤0.05) the increase in the N content in the aerial part of the seedlings. On the other hand, there was a significant reduction in the N accumulation, of physiological variables, growth, biomass, IQD and NUE, which resulted in a negative correlation with the increasing N supply. Very high N doses, having as source the urea, were harmful to the seedlings of Guazuma ulmifolia. The doses between 20 and 38.8 mg dm-3 of N, in general, were those that promoted the best results.

Abstract In face of the global situation, a practice which has been gaining strength is producing seedlings for environmental restoration. Among the species that stand out for such activity is Hymenaea stigonocarpa. However, little is known about their nutritional requirements. The objective of this study was to evaluate the morphophysiological behavior of H. stigonocarpa seedlings submitted to phosphorus doses. The design was completely randomized with five doses (0, 100, 200, 300 and 400 mg dm-3) and four replicates. Physiological, morphological, biomass and phosphorus content analyses were performed. There was a difference for root mass ratio, leaf mass ratio, shoot mass ratio, leaf area and root area. The dose of 200 mg dm-³ is recommended for H. stigonocarpa seedlings.

RESUMO O estado de Mato Grosso, com uma área de 903 357 km², não possui uma metodologia oficial para estimar a acidez potencial do solo (H + Al), e sua determinação pelo método padrão é onerosa e demorada. O objetivo deste estudo foi comparar os valores estimados de (H + Al) determinados pelo método padrão de acetato de cálcio com os obtidos por três métodos tampão, a saber, tampão Shoemaker, McLean and Pratt (SMP), tampão Sikora e tampão Santa Maria (SMB), considerando amostras das principais classes de solos cultivados no estado de Mato Grosso. Para isso, 196 amostras de solo foram coletadas na camada arável (0-20 cm) em diferentes sistemas agropastoris e nativos adjacentes. Os modelos estatísticos obtidos foram comparados com modelos hipoteticamente inadequados utilizados pelos laboratórios, pois não há calibração para solos no estado. Após as análises laboratoriais, os pares de valores determinados de H+Al e o pH de equilíbrio corresponde de cada solução tampão foram submetidos a análise de correlação e regressão não-linear (p < 0,05). Verificou-se que o método SMB, que não gera resíduos de poluentes no meio ambiente, foi melhor que os métodos Sikora e SMP para substituir o método padrão, usando a equação H + Al (cm 3 c dm-3) = 51.189-25.70 ln (pHSMB) (R2 = 0,88, P < 0,0001). Assim, se os laboratórios usarem equações não calibradas para estimar a acidez potencial do solo, isso implica subestimar ou superestimar a recomendação de calcário, o que pode comprometer a produtividade das culturas no Mato Grosso.

ABSTRACT Mato Grosso, with a total area of 903357 km², does not have an official methodology for estimating soil potential acidity (H + Al), and determination of H + Al using the standard method is onerous and time consuming. The objective of this study was to compare estimated values of H + Al determined using the standard calcium acetate method with those obtained using three buffer methods, namely, the Shoemaker, McLean, and Pratt (SMP) buffer, Sikora buffer, and Santa Maria buffer (SMB) methods, with samples of the main classes of cultivated soils in the state of Mato Grosso. A total of 196 soil samples were collected from the arable layer (0-20 cm) in agropastoral and adjacent native systems. Statistical models were obtained and compared with models used by laboratories that are hypothetically inadequate because there is no calibration for soils in the state. After laboratory analyses, the paired H + Al and equilibrium pH values corresponding to the equilibrium of each buffer solution (SMP buffer, SMB, and Sikora buffer) were subjected to nonlinear regression analysis (P < 0.05). The SMB method, which does not release pollutant residues into the environment, was better than the Sikora and SMP methods for replacing the standard method used in state laboratories for soil analysis, that is, H + Al (cm3 c dm-3) = 51.189 -25.70 ln(pHSMB) (R2 = 0.88, P < 0.0001). Thus, if laboratories use uncalibrated equations to estimate soil potential acidity, the recommended limestone correction will be underestimated or overestimated, which may compromise crop productivity in Mato Grosso.

Abstract Acrocarpus fraxinifolius, known as Indian cedar, has little forestry development in Brazil. Thus, the objective of this study was to find the best relation between nutrition and container (tube) volume in seedlings of this species. The experiment was carried out in a 2 × 8 factorial scheme (2 containers and 8 fertilizers), with polypropylene tubes of 50 and 110 cm³ being tested, and the following fertilization treatments: one control, 4 increasing doses of osmocotee plus: 3, 5, 7, 9 kg per m³ of substrate, and fractionated mineral fertilizations with cover manure. It was possible to note that the tube with the highest volume (110 cm³) presented better results for the morphological characteristics. However, when analyzing the physiological variables, it is clear that the 50 cm³ tubes presented similar results to the largest volume tube when well fertilized. It is concluded that the indicated to form seedlings of the species is the combination of tubes of 50 cm³ with the fertilization or double of this recommendation.