Solos
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11737
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Resultados da Pesquisa
Item New methods for estimating lime requirement to attain desirable pH values in Brazilian soils(Sociedade Brasileira de Ciência do Solo, 2020-04-21) Teixeira, Welldy Gonçalves; Alvarez V., Víctor Hugo; Neves, Júlio César LimaIn Brazil, empirical models are traditionally used to determine lime requirement (LR), but their reliability is doubtful in most cases, since they can lead to under- or overestimation of LR for different soil types. In this study, the most critical characteristics influencing LR were selected to develop reliable models for predicting LR that raise soil pH to optimum values for crop production in Brazil. Soil samples (n = 22) with varying proportions of clay (5-88 %) and organic matter (OM) levels (3.78-79.35 g kg-1) were used to develop the models. Organic matter and potential acidity (HAl) combined with ΔpH [target pH(H2O) - initial pH(H2O)] were the best predictor variables for estimating LR. Four models were developed (OMpH5.8, OMpH6.0, HAlpH5.8, and HAlpH6.0) for estimating LR to attain target pH values of 5.8 or 6.0 with reasonably high prediction performance (0.758≤ R2 ≤0.886). An algorithm was further developed for selecting the LR to be recommended among those estimated by the models. The proposed algorithm enables to select the minimum LR that ensure the adequate supply of Ca and Mg to plants and does not exceed the levels of soil HAl, thus preventing excessive pH increase. The new predictive models were less sensitive to predict LR high enough to meet Ca2+ and Mg2+ requirements of plants in soils containing levels of HAl lower than 5 cmolc dm-3 and OM lower than 40 g kg-1. However, they ensured an adequate supply of Ca2+ and Mg2+ to plants and avoided the overestimation of LR for most soils used in this research. Validation via an independent dataset (n = 100 samples) confirmed the good predictive performance of the models across a wide range of soil types. In summary, the proposed models can be used as good alternatives to traditional methods for predicting LR for a great variety of Brazilian soils. Further, they are versatile and may be easily deployed in soil testing laboratories, since soil pH, OM, and HAl are characteristics determined in routine analysis.Item Establishment of critical nutrient levels in soil and plant for eucalyptus(Sociedade Brasileira de Ciência do Solo, 2020-03-03) Neto, Antonio João de Lima; Neves, Júlio César Lima; Martinez, Herminia Emilia Prieto; Sousa, Jailson Silva; Fernandes, Loane VazThe adoption of more productive and nutrient-demanding genotypes, in addition soils with low availability of nutrients of soils under forest plantations, lead high fertilizer demand and justify research that seeks to rationalize the use of these inputs. Therefore, we aimed with this research to determine classes of interpretation of soil fertility using boundary line (BL) and estimate macronutrient sufficiency ranges for eucalyptus. Fertility classes and sufficiency ranges were obtained using a database of areas cultivated with eucalyptus in the Central-East region of Minas Gerais, Brazil, totaling 689 plots, containing information on yield, leaf contents, and soil chemical properties. Scatter plots were drawn relating the mean annual increment (MAI) in trunk volume (relative) with soil organic matter (OM), phosphorus (P), potassium (K+ ), calcium (Ca2+), and magnesium (Mg2+) of the 0.00-0.20 m layer. Those graphs and equations were used to estimate soil fertility classes. Leaf contents of N, P, K, Ca, and Mg were plotted with soil contents of OM, P, K+ , Ca2+, and Mg2+. Using the Quadrant Diagram of the plant-soil Relationship (QDpsR) method, horizontal and vertical lines were drawn separating the cloud of points in four quadrants. With the points at the quadrants III and I, regression equations were fitted. To obtain foliar sufficiency ranges, soil values of critical and optimal levels of OM, P, K+ , Ca2+, and Mg2+, obtained by BL, were substituted in the equations generated by the QDpsR method. The appropriate soil content ranges determined by BL for productivity of 47.7 m3 ha-1 yr-1 were: 24.75-38.28 g kg-1 of OM, 8.5-14.6 mg dm-3 of P, 100.0-150.35 mg dm-3 of K+ , 0.77-1.47 cmolc dm-3 of Ca2+, and 0.25-0.43 cmolc dm-3 of Mg2+. Leaf content ranges determined by QDpsR are: 19.4-21.3 g kg-1 of N, 1.0-1.2 g kg-1 of P, 8.5-10.6 g kg-1 of K, 4.8-6.1 g kg-1 of Ca, and 1.9-2.4 g kg-1 of Mg. The critical levels of nutrients in the soil, obtained by the BL method, and the leaf sufficiency ranges, obtained using the QDpsR method, are similar to those existing in the literature. This indicates that this methodology is reliable in establishing standards and that the critical levels obtained can be used to improve the recommendation of fertilizers for eucalyptus.Item Evaluation of traditional methods for estimating lime requirement in Brazilian soils(Revista Brasileira de Ciência do Solo, 2020-08-10) Teixeira, Welldy Gonçalves; Alvarez V., Víctor Hugo; Neves, Júlio César Lima; Paulucio, Rodrigo BazzarellaThe optimal soil pH for most annual crops in Brazil varies between 5.7 and 6.0. Numerous methods have been developed for estimating lime requirement (LR), but they vary widely in their predictions and fail to raise pH to desired values for optimum crop production in the highly weathered soils of Brazil. The objectives of this study were to (i) compare seven traditional methods for estimating LR in Brazilian soils; (ii) assess the effects of LR predicted by these methods on soil-acidity related properties, and (iii) determine if these methods are predicting LR to attain target pH values of 5.8 and 6.0, which are within the pH range recommended to optimize crop yields. The traditional LR methods evaluated in this study are based on the following criteria: exchangeable acidity (EA), base saturation (BSAT), exchangeable acidity along with Ca 2+ and Mg 2+ as proposed by the 4th (MG4A) and 5th (MG5A) Approximations to the Minas Gerais State, SMP soil-buffer pH (SMP), potential acidity (PA), and soil pH along with organic matter (pHOM). These methods were compared with the standard incubation method using correlation-regression analysis and, alternatively, the identity test designed for assessing equivalence between methods. Representative agricultural soils (n = 22) were incubated for 60 days with incremental amounts of lime determined by the tested methods. On average, LR predictions differed among methods, and increased in the following order: EA < BSAT ≈ MG5A ≤ MG4A ≈ SMP ≤ PA < pHOM. Suitable changes in soil pH, exchangeable acidity, potential acidity, base saturation, and Ca 2+ and Mg 2+ were achieved upon application of LR estimated by all methods except the EA and pHMO, which resulted in undesirable soil acidity characteristics. All methods evaluated in this study were unable to predict LR for attaining target pH values of 5.8 and 6.0 as revealed by the identity test, even though they were moderate to strongly correlated with the standard incubation method as indicated by the correlation-regression analysis. Further research should focus on the development of reliable methods for predicting LR to attain desired pH values and consequently maximize crop production on Brazilian soils.Item Universality of Kenworthy and DRIS norms for prata and cavendish bananas grown in two environments(Revista Brasileira de Ciência do Solo, 2020-11-23) Filho, Vagner Alves Rodrigues; Neves, Júlio César Lima; Donato, Sérgio Luiz Rodrigues; Guimarães, Bruno Vinícius CastroTissue analysis results are interpreted by comparing them with nutrient standards; however, using universal standards may lead to a misleading nutritional diagnosis. This study aimed to evaluate the degree of universality of Kenworthy and DRIS norms for irrigated ‘Prata-Anã’ (AAB) and ‘Grande Naine’ (AAA) banana plants grown in two environments. The study was carried out using a database containing leaf nutrient contents and yield data of two farms located in Ponto Novo, Bahia State, and Missão Velha, Ceará State, Brazil. A reference population was that with yields above the average yield plus 0.5 standard deviation. Using a reference population, the mean, standard deviation, and coefficient of variation of nutrient content and dual nutrient ratios were calculated for each site × cultivar combination. To verify the homogeneity of variance among populations, F-test was used (p≤0.05). Means were compared using t-test (p≤0.05). Differences in climate and soil at each farm explain the high frequency of significant differences found between norms for each site. Kenworthy norms established for interpreting leaf nutrient contents of P, K, Ca, Mg, S, Cu, Fe, Mn, and Zn for ‘Prata-Anã’ grown in Ceará were higher than those in Bahia, while for N and B contents, the norms were higher in Bahia. This is due to differences in soil fertility and alkalinity affecting nutrient availability as well as non-nutritional factors. Kenworthy and DRIS norms for ‘Prata-Anã’ and ‘Grande Naine’ bananas grown in Ceará have higher variability and are greater than for those grown in Bahia. Norms are less convergent for ‘Prata-Anã’ than ‘Grande Naine’. Site- and cultivar-specific norms are recommended over universal ones for assessing the nutritional status of ‘Prata-Anã’ and ‘Grande Naine’ banana plants cultivated in different environments.Item Clonal teak litter in tropical soil: decomposition, nutrient cycling, and biochemical composition(Revista Brasileira de Ciência do Solo, 2020-10-05) Cavalcante, Valéria Santos; Santos, Márcio Luiz dos; Cotta, Luisa Carla; Neves, Júlio César Lima; Soares, Emanuelle Mercês BarrosLitter decomposition dynamics and nutrient release are also dependent on their biochemical composition, and such information is important for adequate nutritional management but is still incipient for plants like teak. This study aimed to evaluate the decomposition dynamics, nutrient release, and biochemical composition of clonal teak litter. The study was conducted in areas of clonal teak stands, in São José do Rio Claro, Mato Grosso, Brazil. Litter collectors were arranged in the area to collect material along the entire dry period. Subsequently, this litter was placed in litter bags, which were distributed in the area. The litter bags were collected every month, for 0.91 years, to determine the dry matter and mineral nutrient contents, in order to estimate the decomposition and nutrient release. Litter biochemical composition was determined at the times of 0, 0.25, 0.58, 0.75, and 0.91 years. Teak litter, essentially leaves, had a half-life time (t 1/2 ) of dry matter and C of 0.74 years, due to the high content of insoluble lignin, which corresponds to 2.28 Mg ha -1 of dry matter and 1.2 Mg ha -1 of C. The t 1/2 values of N and P release (1.20 and 1.01 years) were higher than those of K, Ca, and Mg (0.08, 0.47, and 0.66 years, respectively). Hence, the nutrient release rate of the litter followed the descending order: K > Ca > Mg > P > N. The litter biochemical composition at the end of the experimental period showed reductions of 18.7 % in polysaccharides and holocellulose, 56 % in polyphenols, 56.3 % in tannins, 22.2 % in extractives, and 28.5 % in soluble lignin; and increases of 25.6 % in insoluble lignin and 22.6 % in total lignin. These data are useful for the balance of carbon and mineral nutrients and to support fertilization management in teak plantations in low-fertility soils.Item Linha de fronteira e chance matemática na determinação do estado nutricional de pitaia(Revista Ciência Agronômica, 2016-10) Deus, José Aridiano Lima de; Almeida, Edmilson Igor Bernardo; Corrêa, Márcio Cleber de Medeiros; Crisostomo, Lindbergue Araujo; Neves, Júlio César LimaCom o presente trabalho objetivou-se avaliar, através dos métodos linha de fronteira e chance matemática, o estado nutricional de pitaias submetidas a combinações de doses crescentes de nitrogênio-potássio (N-K) e fósforo-zinco (P-Zn). Foram aplicadas cinco doses de N (0; 150; 300; 450 e 600 mg dm-3) e K (0; 75; 150; 225 e 300 mg dm-3) no experimento I, e cinco doses de P (0; 75; 150; 255 e 300 mg dm-3) e Zn (0; 2; 4; 6 e 8 mg dm-3) no experimento II. Ambos os experimentos foram arranjados em esquema fatorial 5 x 5, com quatro blocos ao acaso. Houve bastante similaridade entre as faixas de suficiência obtidas pela chance matemática e linha de fronteira, exceto para o fósforo. As faixas de suficiência obtidas pela linha de fronteira foram mais amplas que as obtidas pela chance matemática. O método linha de fronteira apresenta elevada capacidade preditiva no ajuste dos dados, demonstrando ser uma importante ferramenta na obtenção de faixas de suficiência e valores de referência para estudos posteriores de diagnose nutricional em pitaia.Item Carbono orgânico e estabilidade de agregados de um Latossolo Vermelho sob diferentes manejos(Pesquisa Agropecuária Brasileira, 2005-05) Wendling, Beno; Jucksch, Ivo; Mendonça, Eduardo de Sá; Neves, Júlio César LimaO objetivo deste trabalho foi verificar a influência de diferentes manejos no carbono orgânico e na estabilidade de agregados em um Latossolo Vermelho. Os seguintes tratamentos foram avaliados: PDs - plantio direto, por quatro anos, com a sucessão milho (silagem)/soja; PDg - plantio direto, por quatro anos, com a sucessão milho/milho/milho/soja; PDtf - três anos contínuos, com tifton (feno), e no quarto ano, soja sob plantio direto; SC - sistema convencional com soja, nos últimos quatro anos; e MN - mata nativa. A estabilidade de agregados foi expressa pelos índices: diâmetro médio ponderado, diâmetro médio geométrico, porcentagem de agregados maiores que 2,0 mm estáveis em água e índice de estabilidade de agregados. Em todos os tratamentos, houve diminuição da estabilidade de agregados com o aumento da profundidade. Os tratamentos cultivados tiveram seus índices de agregação reduzidos em relação à mata nativa. O sistema convencional apresentou os menores índices de agregação. O uso da gramínea perene tifton foi o tratamento que promoveu a melhor recuperação da estabilidade de agregados em água. Correlações significativas e positivas foram obtidas entre carbono orgânico total e os índices de estabilidade estudados.Item Parameterization of the 3- PG model for eucalypt in the region of Cerrado in Minas Gerais state(Ciência Florestal, 2012-07) Borges, Jarbas Silva; Neves, Júlio César Lima; Lourenço, Helton Maycon; Barros, Nairam Félix de; Dias, Sharlles Cristhian MoreiraThe 3-PG model is an effective tool for determining the productive productivity of eucalypt plantations. However, the model parameterizations available today produce underestimated results when they are applied to Cerrado region of Minas Gerais state. Thus, in this paper we aimed to parameterize the 3-PG model for fast-growing eucalypt clonal plantations in the Cerrado region of Minas Gerais state, Brazil. To perform the parameterization, there were collected data from stands of Eucalyptus grandis x Eucalyptus urophylla clonal hybrid, throughout an age range, from very young stands (about 3 months old) until adult stands (about 7 years old), in two regions (Curvelo and Itacambira - MG). The growth estimates obtained by 3-PG were compared with data from forest inventory in both regions, until 84 months old. The application of 3-PG model using the set of parameter and variable values determined in the study allowed to describe, accurately, the growth patterns of forests stands in the Cerrado region of Minas Gerais state. Thus, it follows that the parameterization upgraded the performance of the model that resulted in accurate estimates of growth.Item Relações entre parte aérea e raízes em povoamentos de teca(Revista Ceres, 2018-11) Neves, Júlio César Lima; Behling, Maurel; Felipe, Rafaella Teles Arantes; Farias, Jaqueline Bento; Carvalho, Géssica deHá pouca informação disponível sobre a relação entre folhas e raízes de teca, cultivada no Brasil. O objetivo deste trabalho foi avaliar se a biomassa dos componentes da parte aérea e a área foliar são bons estimadores da biomassa e da superfície de raízes, em povoamentos de teca (Tectona grandis). Na amostragem, realizada em árvores de teca, com 17 e 90 meses de idade, em parcelas estabelecidas em talhões comerciais em Tangará da Serra, MT, foram individualizados os componentes raízes, folhas, galhos e tronco, determinando-se, posteriormente, suas biomassas secas, AFE (área foliar específica) e ARE (área radicular específica). A superfície da folha de uma árvore jovem é quatro vezes maior que a superfície de uma folha de árvore adulta de teca. A superfície de raízes finas (< 2 mm) das árvores adultas é quatro vezes maior que a superfície de raízes médias (2 a 5 mm). A AFE foi de 13,14 m2 kg -1 e a ARE de 13,86 m2 kg -1 , indicando eficiência semelhante quanto à utilização do C na produção de superfícies para aquisição de radiação solar, água e nutrientes e, ainda, que há sincronia na alocação de C entre folhas e raízes finas para formação de novos tecidos foliares e radiculares. O IAF (Índice de Área Foliar) médio foi 1,2 m 2 m -2 , nas árvores jovens, e de 8,3 m 2 m -2 , nas árvores adultas. As relações entre áreas foliares e biomassas das partes aéreas com as áreas superficiais e biomassas de raízes finas e médias refletem os padrões de alocação de carbono nas árvores, até a idade em que foram avaliadas. A área foliar é um bom estimador da área superficial de raízes de teca.Item Influência do clima na susceptibilidade ao adensamento de três classes de latossolos brasileiros(Revista Ceres, 1999-07) Jantsch, Ricardo Luís; Olszevski, Nelci; Costa, Liovando Marciano da; Neves, Júlio César LimaObjetivou-se verificar a influência do clima, por intermédio da altitude, na susceptibilidade ao adensamento de três classes de latossolos brasileiros. Foram utilizados dados dos horizontes A1 e B22 de perfis de três classes de latossolos (LR, LE e LV), constantes de boletins de levanta mento de reconhecimento de solos do CNPS da EMBRAPA, cujos resultados de densidade do solo encontram-se disponíveis. As características altitude, grau de floculação, capacidade de troca de cátions total, saturação de bases, índice de intemperismo; teores de argila, carbono orgânico, caulinita, goethita, hematita e gibbsita foram submetidas a análise de trilha, permitindo avaliar os seus efeitos diretos e indiretos sobre a densidade do solo. Verificou-se maior influência dos fatores climáticos na camada superficial do solo, modificando o acúmulo de carbono orgânico e a lixiviação de sílica. Entretanto, pode-se inferir que os solos de uma mesma classe situados em altitudes menores apresentam maior susceptibilidade ao adensamento, implicando na utilização de um manejo diferenciado em relação aqueles situados em locais mais elevados.