ABSTRACT Analyses of fertilizer are essential to ensuring that fertilizer sold to final users presents chemical and physical qualities in the range determined by law. As regards the sampling of fertilizers, the official method currently used in Brazil for sampling preparation is to reduce the size of the sample (from ~ 3 kg to ~ 0.25 kg) by quartering, followed by grinding (so as to pass through a 0.85 sieve) and nutrient quantification. Herein, we propose an alternative method of sampling preparation by grinding the total sample (~ 3 kg) before quartering to improve accuracy and reduce segregation during quartering. Six formulations of fertilizers (basal samples) were weighed (0.01 kg precision) and sampled according to the two methods (official and alternative), followed by the quantification of nutrient concentration in duplicate. Results showed that both methods presented similar nutrient concentrations for most formulations compared to the basal samples. However, the alternative method presented higher precision (less variation between replicates) and accuracy (versus the basal samples) than the official method. Consequently, the alternative method can be used for sampling preparation fertilizers with high accuracy and precision in determining nutrient concentration. law from 025 0 25 0.2 so 085 85 0.8 sieve Herein ( samples 0.01 001 01 (0.0 alternative, , alternative) duplicate However less replicates versus Consequently 02 2 0. 08 8 0.0 00 (0. (0

ABSTRACT Afforestation and reforestation were the challenges the farmer can seize to plant a culture that can capture more carbon than the amount emitted for cultivation. Assuming that the land was legally rented and owned, and part of an area that had not been obtained through recent deforestation, the main questions were: “why a farmer should have preferred to reserve the area to plant trees?”; and “How much did one ton of Carbon Dioxide [CO2] have to be rewarded to buy this opportunity?” This work had the target to estimate which was the minimum price for carbon credit so that the farmer will plant a forest instead of using the soil for grain cultivation. Based on the analysis that economic aspects and profit were the main drivers considered by the farmer to decide how to use the soil in case the area was not classified as Legal Reserve or Permanent Protection Area, seeking the usage which maximized the value per hectare. Considering a eucalyptus commercial forest planted under the premises of the current study, results showed that a price of around 24 BRL per ton of CO2 in 2021 is enough to turn it economically feasible. Business case had been estimated with and without profit coming from the commercial use of forest, and even assuming that no wood is cut and sold, the 2021 price of 40,48 BRL per ton of CO2 can ensure more profit than grain production over 14 years timeframe, allowing the farmer to make money beyond the usual commercial use of a forest. cultivation owned deforestation why trees trees?” How CO [CO2 opportunity opportunity? Area hectare study 2 202 feasible sold 4048 40 48 40,4 1 timeframe trees? [CO 20 404 4 40,

RESUMO Florestar e reflorestar foram os desafios que o agricultor pode enfrentar para plantar uma cultura capaz de capturar mais carbono do que a quantidade emitida para o cultivo. Partindo do pressuposto de que a terra era legalmente arrendada e própria, e parte de uma área que não havia sido obtida por meio de desmatamento recente, as principais questões eram: “por que um agricultor teria preferido reservar a área para plantar árvores?” e “Quanto uma tonelada de Dióxido de Carbono [CO2] teve que ser recompensada para comprar esta oportunidade?” Este trabalho teve como objetivo estimar qual o preço mínimo do crédito de carbono para que o agricultor plante uma floresta ao invés de usar o solo para cultivo de grãos. Com base na análise, os aspectos econômicos e de lucro foram os principais direcionadores considerados pelo agricultor para decidir como usar o solo caso a área não fosse classificada como Reserva Legal ou Área de Proteção Permanente, buscando o uso que maximizasse o valor por hectare. Considerando uma floresta comercial de eucalipto plantada nas dependências do presente estudo, os resultados mostraram que um preço em torno de R$ 24 por tonelada de CO2 em 2021 é suficiente para torná-la economicamente viável. O caso de negócios foi estimado com e sem lucro proveniente do uso comercial da floresta e, mesmo assumindo que nenhuma madeira seja cortada e vendida, o preço de 2021 de R$ 40,48 por tonelada de CO2 pode garantir mais lucro do que a produção de grãos ao longo de 14 anos, permitindo ao agricultor ganhar dinheiro além do uso comercial usual de uma floresta. própria recente eram árvores árvores? Quanto CO [CO2 oportunidade oportunidade? análise Permanente hectare estudo R 2 202 tornála torná la viável vendida 4048 40 48 40,4 1 anos [CO 20 404 4 40,

RESUMO O objetivo deste trabalho foi avaliar o acúmulo de potássio e cloreto na produtividade e qualidade de tubérculos de batata, cultivar Asterix, sob aplicação de duas fontes de fertilizante potássico (KCl e K2SO4.2MgSO4) e combinações destes. O delineamento experimental foi em blocos casualizados, com cinco tratamentos e quatro repetições, em esquema fatorial com parcela subdividida. A presença de cloreto na fertilização potássica acima de 61,8% da dose recomendada afeta o crescimento das plantas de batata, com menor acúmulo de matéria seca na parte aérea. Isso não ocorre nos tubérculos devido à menor translocação de nutrientes para os tubérculos. O acúmulo de K é variável entre os níveis, dependendo dos íons companheiros das fontes. Ao longo do ciclo, a quantidade de cloreto aumenta na parte aérea e tubérculos com o aumento da % de KCl. A produtividade total é afetada pelo uso da combinação das doses da fonte de potássio, com produtividade máxima de 41,3 t ha-1 com a associação entre 64,5% KCl e 36,5% KCl and K2SO4.2MgSO4. Os sólidos solúveis não variaram com as fontes na dose de 180 kg ha-1 K2O.

ABSTRACT The objective of this study was to evaluate potassium and chloride accumulation in, and the yield and quality of the potato tubers of the Asterix cultivar, under the application of two potassium fertilizer sources (KCl and K2SO4.2MgSO4) and their combinations. The experimental design was a randomized complete block with five treatments and four replications in a factorial scheme with a subdivided plot. The presence of greater than 61.8% of the recommended dose of chloride in potassium fertilization affects potato plant growth, with less dry matter accumulation in the aerial part. This does not occur in the tubers because of lower nutrient translocation to the tubers. K accumulation varies between levels depending on the companion ions of the sources. Throughout the cycle, the amount of chloride increased in the aerial parts and tubers with an increase in the percentage of KCl. The total productivity is affected by the use of a combination of potassium sources in different proportions, with a maximum yield of 41.3 t ha-1 with a combination of 64.5% KCl and 36.5% K2SO4.2MgSO4. Soluble solids did not vary with the sources at a dose of 180 kg ha-1 K2O.

RESUMO A qualidade do solo é importante para proporcionar uma condição adequada à produção de alimentos, fibras e energia sem alterações significativas no ambiente. Índices de fragilidade do solo têm sido apresentados como indicadores de qualidade do solo (exemplo, porosidade do solo e estoques de carbono), devido à fácil modificação pelo manejo do solo e sistemas de cultivo. Um estudo foi realizado para explicar como o carbono atua na distribuição de macro e microporos. Verificou-se que em solos de textura fina a distribuição de microporos foi maior que macroporos devido ao aumento natural de argila no solo. O carbono orgânico criou poros orgânicos que impactaram positivamente a microporosidade.

ABSTRACT Soil quality is important for providing adequate conduction for the production of food, fiber, and energy without significant alterations in the environment. Fragile soil indexes have been presented as soil quality indicators (i.e., soil porosity and carbon stocks) due to the easy modification by soil management and crop cultivation systems. The objective of this study was to determine and discuss how carbon operates in the distribution of macro- and micropores in fine-textured soils in tropical conditions using sugarcane and coffee production. The experiments were conducted in the region of Triângulo Mineiro, Minas Gerais, Brazil, using sugarcane cultivation (Saccharum officinarum) and coffee (Coffea sp.) in the conditions of the Brazilian Cerrado. It was verified that the distribution of micropores in fine-textured soils was higher than macropores due to the natural increment of clay in the soil. Organic carbon produced organic pores that positively impacted microporosity.

RESUMO O uso do organomineral tem um alto potencial para substituir fertilizantes sintéticos. O objetivo do presente estudo foi encontrar uma taxa de substituição ideal do organomineral em comparação com o fertilizante mineral para aumentar a produtividade e a qualidade da batata. O delineamento experimental foi em blocos casualizados, com quatro repetições, utilizando seis tratamentos: quatro doses substitutas de fertilizante organomineral (25, 50, 75, e 100% da demanda de fertilizante mineral), uma dose de fertilizante mineral (100% de fertilizante mineral) e controle (sem aplicação de fertilizante). As doses do organomineral foram testadas como alternativas para substituir de 25 a 100% do fertilizante mineral. A produtividade e qualidade da batata (total e em classes) e o teor de nutrientes na planta e no solo foram monitorados. Houve correlação positiva entre pH e conteúdo de sólidos solúveis totais com a produtividade. A batata acumulou maiores teores de potássio > nitrogênio > fósforo nas folhas, caules e tubérculos. A dose de 3,7 t ha-1 do organomineral (equivalente a 100% de fertilizante mineral) foi a taxa ideal para aumentar a produtividade e qualidade da batata. O organomineral é uma alternativa viável para aumentar a qualidade e a produtividade da batata com um incremento positivo de nutrientes nas plantas e no solo.

ABSTRACT Organomineral fertilizer has great potential to replace synthetic fertilizers. The goal of this study was to determine an optimal substitution rate of organomineral fertilizer for mineral fertilizer to increase potato yield and quality. The experimental design was a randomized complete block with four replicates and six treatments, namely four substitution rates of organomineral fertilizer application (25, 50, 75, and 100% of mineral fertilizer demand), one rate of mineral fertilizer application (100% of mineral fertilizer demand), and the control (no fertilizer application). The organomineral application rates were tested as an alternative to substitute 25 to 100% of mineral fertilizer. The potato yield (total and in-class) and quality and plant and soil nutrient contents were monitored. The pH and total soluble solid contents had positive correlations with yield. Potatoes accumulated higher contents of K > N > P in the leaves, stems, and tubers. The organomineral fertilizer application rate of 3.7 t ha-1 (equivalent to 100% of mineral fertilizer demand) was the optimal rate to increase potato yield and quality. Organomineral fertilizer is a viable alternative to increase potato quality and yield and to increase plant and soil nutrient contents.

Resumo O objetivo deste trabalho foi avaliar a eficiência de fontes e doses de magnésio solúvel (MnSO4.H2O) e insolúvel (MnCO3) nos processos de absorção, transporte e redistribuição deste nutriente na soja (Glycine max), bem como na produtividade da cultura, em solo de Cerrado. O delineamento experimental foi em blocos ao acaso, em arranjo fatorial 4×2 – quatro doses (150, 250, 350 e 450 g ha−1) × duas fontes (MnSO4.H2O e MnCO3) de Mn –, com quatro repetições. Nas safras de 2015/2016 e 2016/2017, realizaram-se adubações foliares no terceiro trifólio e avaliaram-se os conteúdos de Mn e a produtividade da soja. Em ambas as safras, a fertilização foliar com Mn aumentou os teores do nutriente nas folhas, nos caules e nos grãos, mas não afetou o rendimento de grãos e a produção de matéria seca. Os teores máximos de Mn nas folhas foram obtidos com doses entre 150 e 450 g ha−1. A aplicação de MnSO4.H2O aumentou a absorção, o transporte e a redistribuição de Mn na planta, com desempenho superior ao de MnCO3. A fertilização foliar com MnSO4.H2O em soja, em solo de Cerrado, aumenta os teores de Mn nas folhas, mas não a produtividade e a produção de matéria seca.

Abstract The objective of this work was to evaluate the efficiency of sources and rates of soluble (MnSO4.H2O) and insoluble (MnCO3) manganese on the processes of uptake, transport, and redistribution of this nutrient in soybean, as well as on crop yield, in Cerrado soil. The experimental design was randomized complete blocks in a 4×2 factorial arrangement – four rates (150, 250, 350, and 450 g ha−1) × two sources (MnSO4.H2O and MnCO3) of Mn –, with four replicates. In the 2015/2016 and 2016/2017 crop seasons, foliar fertilizations were carried out on the third trifoliate leaflet, and Mn content and soybean yield were evaluated. In both crop seasons, Mn foliar fertilization increased the contents of the nutrient in leaves, stems, and grains, but did not affect grain yield and dry matter production. The maximum Mn contents in leaves were obtained with rates between 150 and 450 g ha−1. The fertilization with MnSO4.H2O increased Mn uptake, transport, and redistribution in the plant, with a performance superior to that of MnCO3. Foliar fertilization with MnSO4.H2O in soybean, in a Cerrado soil, increases Mn contents in the leaves but not yield and dry matter production.

Abstract Analyses of potential sources and products that aim to balance nutrients in soil and plants; improve physical, mineral, and biological attributes of soil; and reduce environmental impacts require greater attention. Therefore, the aim of this study was to evaluate the agronomic efficiency of organomineral fertilizers (OMFs) in Atlantic potato cultivars. The experimental design was a randomized complete block design, with four treatments and six replicates. The treatments consisted of NPK mineral fertilizers (recommended according to soil analysis and nutritional crop requirements) as a control and NPK plus OMF according to composition and form of application (planting, ridging, and leaf), referred to as managements A and B, which indicate the amount of nutrients that the plants received. Therefore, treatments with OMF were designated as follows: P-OMF(A): organomineral fertilizer management applied through the planting furrow; PR-OMF (B): organomineral fertilizer management applied through the planting and ridging, and PR-OMF (B) + L-OMF (B): organomineral fertilizer management applied through the planting and ridging and by leaf application. The applications of P-OMF (A) and PR-OMF (B) + L-OMF (B) resulted in positive effects on special class production and total productivity of Atlantic potato tubers, which increased by 12% to 16% and 11% to 15.5%, respectively. The application of PR-OMF (B) + L-OMF (B) improved the soluble solid content by 2.7% compared to the control (absence of OMF application). Therefore, organomineral fertilizers have the potential to improve the quantitative and qualitative attributes of potatoes.

Resumen El análisis de las posibles fuentes y productos que apuntan a equilibrar los nutrientes en el suelo y las plantas, mejorar los atributos físicos, minerales y biológicos del suelo y reducir los impactos ambientales necesitan más atención. En este sentido, el objetivo de este estudio fue evaluar la eficiencia agronómica de los fertilizantes organominerales (OMF) en papa, cultivar Atlantic. El diseño experimental fue un bloque completo aleatorizado, con cuatro tratamientos y seis repeticiones. Los tratamientos consistieron en el control -fertilizantes minerales NPK (recomendado de acuerdo con el análisis del suelo y los requerimientos nutricionales del cultivo); y NPK más OMF de acuerdo con: composición y forma de aplicación (plantación, crestas y hojas), que fue llamado a lo manejo A y B. Lo manejo A y B se relaciona con las tasas de nutrientes que recibieron las plantas. Por lo tanto, los tratamientos con OMF se designaron como: P-OMF (A): manejo de fertilizantes organominerales (A) aplicado en el surco de siembra; PR-OMF (B): manejo de fertilizantes organominerales (B) aplicada en la siembra y la formación de surcos y PR-OMF + L-OMF (C): manejo de fertilizantes organominerales (B) aplicada en la siembra, la formación de surcos y la aplicación de hojas. Las aplicaciones de P-OMF (A) y PR- PR-OMF (B)+ L-OMF (B) dan como resultado una acción positiva para la producción de Clase Especial y la productividad total de los tubérculos del cultivar Atlantic, con incrementos entre 12 y 16% y 11 a 15.5%, respectivamente. La aplicación de PR-OMF (B)+ L-OMF (B) mejora en un 2.7% el contenido de sólidos solubles, en comparación con la ausencia de aplicación de OMF. Por lo tanto, los fertilizantes organominerales presentan potencial para mejorar los atributos cuantitativos y cualitativos de las papas.

ABSTRACT The use of nitrification inhibitors (NIs; dicyandiamide - DCD) is an alternative to reduce oxidation of ammonium (NH4+-N) to nitrate (NO3–-N) in the soil, reducing NO3–-N losses from fertilization practices. Based on the hypothesis that DCD reduces conversion of NH4+-N to NO3–-N in tropical soils and inhibits ammonia oxidizing microorganisms (AOM) abundance, soils from the Piracicaba region, São Paulo, with different textures (sand, loam and clay) were incubated with ammonium sulphate (AS) and DCD. Contents of NH4+-N, NO3–-N, soil pH, and AOM abundance were quantified periodically. Ammonium sulphate increased AOM abundance in all soils, but AS+DCD presented AOM abundances similar to the control. During 90 days of incubation, the effectiveness of DCD in reducing NO3–-N production was 1.8, 86.4, and 145.6 mg kg–1, while the effectiveness of DCD in reducing AOM abundance was 1.2, 3.0 and 2.3 × 10–3 g soil–1 for sandy, loamy, and clayey soils, respectively. DCD effectiveness was greater in loamy and clayey soils due to the naturally low nitrification in sandy soils. Application of AS treated with DCD showed potential not only to reduce NO3–-N production in loamy and clayey soils, but also to decrease the soil nitrification rate. Overall, DCD was effective in reducing AOM abundance and conversion of NH4+-N to NO3–-N in loamy and clay soils evaluated here. The increase in clay content directly influences DCD effectiveness in reducing conversion of NH4+-N to NO3–-N.

RESUMO Adubações com fósforo (P) apresentam baixa eficiência devido à adsorção de P na superfície da argila em solos tropicais. O superfosfato complexado com ácido húmico (SSP+HA) é apresentado como uma alternativa para melhorar a eficiência do uso do P e a produtividade das culturas. Nesse sentido, o objetivo deste estudo foi investigar o desempenho do SSP+HA na produção de cana-de-açúcar com incrementos da matéria seca (MS) e conteúdo de P nas plantas. O experimento foi conduzido com duas fontes de P (superfosfato simples-SSP; SSP+HA) e cinco doses (0; 45; 90; 135 e 180 kg ha-1 de P2O5). A dose de 135 kg ha-1 foi usada para explicar o efeito residual do P, coletando solo na cana-planta e primeiro corte. Amostras de caules, ponteiras e raízes foram coletadas para determinar MS e conteúdo de P; ambas variáveis foram usadas para calcular a eficiência de assimilação de fósforo (EaP). Os resultados mostraram que a aplicação de SSP aumentou MS e conteúdo de P nas plantas, com desempenho superior ao SSP+HA. A EaP foi maior no SSP+HA, indicando que o P foi metabolizado de forma mais eficiente, mas não refletiu no aumento de MS. As doses de P aumentaram a produtividade da cana-planta, mas não houve efeito do P aplicado em soqueira, devido ao efeito residual do P aplicado no plantio. O SSP apresentou desempenho superior ao SSP+SH no plantio da cana-de-açúcar. Mais pesquisas são necessárias para melhor ilustrar o efeito do SSP+HA na absorção e translocação do P.

ABSTRACT In tropical soils, the efficiency of phosphorus (P) fertilization is low, due to P adsorption on the surface of the clay. Superphosphate complexed with humic acid (SSP+HA) is presented as an alternative for improving P use efficiency and crop yields. The aim of this study was to investigate SSP+HA performance in sugarcane production including increases in plant dry matter (DM) and P content. The experiment was conducted with two sources of P (simple superphosphate - SSP, SSP+HA) and five doses (0, 45, 90, 135 and 180 kg ha-1 P2O5). The dose of 135 kg ha-1 P2O5 was used to explain the residual effect of P, collecting soil samples from the plant cane and first ratoon. Stalk, top and root samples were collected to determine DM and P content; both variables were used to calculate the P assimilation efficiency (PaE). Results showed that the application of SSP increased the DM and P content of the plants, with superior performance compared to SSP+HA. PaE was greater under SSP+HA, indicating that P was metabolized more efficiently; however this did not reflect in an increase in DM. AThe P rates increased the sugarcane yield in cane plant, but there was no effect of P applied in the first ratoon due to the residual effect of P applied in planting. SSP presented superior performance compared to SSP + SH in sugarcane planting. Further research is needed to better demonstrate the effect of SSP+HA on the absorption and translocation of P.

ABSTRACT: Integrating plant density and nitrogen (N) management is a strategy for improving corn yields, especially for off-season corn production in the tropics. This study tested the hypothesis that increasing plant densities and N rates promotes yield gains for off-season corn production in high-yielding environments. The aim of the study was to investigate the yield performances of two hybrid versions (DKB PRO and DKB PRO3) submitted to three plant densities (55,000; 65,000 and 75,000 plants ha−1) and four N rates (control, 60, 120 and 180 kg ha−1 N). Field trials were undertaken at Uberlândia-MG (site1 and 2) and Pedro Afonso-TO (site 3), Brazil from which data on corn yield parameters were collected and analyzed. Multivariate analysis separated the three trial areas into two groups, presenting high (sites 1 and 2) and low yields (site 3), which were related to weather conditions. There was no influence of a hybrid version or plant densities on crop yields at site 1 or 2. In contrast, there was a positive response to increasing plant densities and the use of DKB PRO3 at site 3. A significant response to N was observed at sites 2 and 3, following a plateau model. Our results suggest that N application rates and plant densities do have the potential to increase off-season corn yields in low yielding environments.

Resumo: O maracujá-amarelo conquistou significativa posição no agronegócio de frutas tropicais, com isso, produtores despertaram interesse para expandir seus pomares, sendo necessárias informações técnicas que garantam a alta produtividade das lavouras. No intuito de observar fatores relacionados ao material propagativo visando a qualidade e a maximização do potencial genético objetivou-se avaliar a germinação e a emergência de sementes de maracujá coletadas em três posições nos frutos e submetidas a métodos de retirada da mucilagem (arilo). Os frutos de maracujá foram seccionados em três partes: distal, mediana e proximal. Cada um destes conteúdos foi submetido aos métodos mecânico e de fermentação para remoção do arilo. Podendo concluir que a posição da semente no fruto do maracujazeiro não interfere na germinação e o método de remoção do arilo por extração mecânica prejudica a germinação e a emergência de plântulas.

Abstract: Yellow passion fruit has conquered a significant position in the agribusiness of tropical fruits; therefore, farmers have been interested in expanding their groves, and technical information that guarantees the high yield of the farmings is needed. Aiming to observe factors related to the propagative material targeted at quality and maximization of the genetic potential, the objective of the study consisted in assessing germination and emergence of passion fruit seeds collected in three positions in the fruits and submitted to different methods of mucilage removal (aryl). The passion fruits were split in three parts: distal, medial and proximal and the contents of each part was divided in two. The content of each part of the fruit was submitted to mechanical and by fermentation methods for removal of aryl. It is concluded that the seed position in the fruit does not interferes with the germination. The aryl removal method by mechanical extraction affects the germination and seedling emergence.

O uso de modelos matemáticos pode ser útil para o entendimento das alterações do uso e manejo do solo e fornecem subsídios para testar cenários futuros, possibilitando desenvolver estratégias de manejo menos impactantes ao meio ambiente. Os objetivos deste trabalho foram: (a) usar o modelo Century v4.5 para simular os efeitos dos usos e manejos sobre os estoques de carbono e nitrogênio do solo em diferentes compartimentos, (b) comparar os estoques medidos e simulados pelo Century, e (c) testar impacto de cenários futuros até o ano de 2100. Os tratamentos avaliados foram Pinus, plantio direto e plantio convencional, com histórico das áreas até o momento da coleta de solo (2004). Para o Pinus foram testados três cenários futuros, um deles simulando o mesmo manejo adotado até o momento da coleta de solo, outro reduzindo os eventos de fogo, além do uso sem preparo do solo para o replantio. Para o plantio direto e plantio convencional, simularam-se dois cenários futuros, um com rotação milho/soja e outro com monocultura de milho. O modelo Century foi sensível às mudanças de manejo adotadas, os compartimentos mais lábeis apresentam maior sensibilidade (ativo e lento), do que o mais estável (passivo). Em relação ao estoque de C, o modelo simulou estoques próximos aos medidos no campo, com um erro mínimo de 0,36%. Para os estoques de N, os valores simulados apresentaram erro de 5,71% para os compartimentos mais lábeis. Os cenários futuros mostraram a importância de se evitar queimadas no Pinus e o uso de monocultivo.

The use of mathematical models can be useful for understanding the changes in the use and management of soil and provide aid in testing future scenarios, making it possible to develop management strategies which have less impact on the environment. The objectives of this study were: (a) to apply the Century Model v4.5 in order to simulate the effects of usages and managements on carbon stocks and soil nitrogen in different compartments; (b) compare both the observed stocks and those simulated by the Century Model; (c) to test the impact of future scenarios until the year 2100. The treatments evaluated were of Pine, under both no-tillage and conventional tillage, using historical data from the areas up until when the soil was sampled (2004). For the pine, three future scenarios were tested, one by simulating the management adopted up to the time the soil was sampled, another by reducing the fire events, as well as by soil usage without any preparation when replanting. For both no-tillage and conventional tillage, two future scenarios were simulated: one with corn and soybean rotation, and the other with a monoculture of corn. The Century model was sensitive to the changes in management which were adopted, the more labile compartments showing greater sensitivity (the active and the slow) than the most stable (passive). In relation to stocks of C, the model simulated values close to those measured in the field, with a minimum error of 0.36%. For stocks of N, the simulated values showed an error of 5.71% for the more labile compartments. For pine, the future scenarios demonstrated the importance of preventing fires, and the use of monocultures.