EUCALYPTUS INICIAL GROWTH ON HUMIC CAMBISOL WITH APPLICATION OF LIMESTONE, GYPSUM, AND LIME MUD

The high demand for forest products in Brazil estimates a 2 million hectares increase in reforestation areas over the next 10 years, highlighting Eucalyptus species. However, these crops usually occur in acid soils that need correction to achieve high productivity. Besides limestone, lime mud, a residue from the cellulose industry, and gypsum can also be used as correctives, but there are doubts about doses and ways of application with the best results. Thus, were evaluated the soil chemical attributes, foliar nutrient content, and initial growth of a Eucalyptus dunnii Maiden crop in response to the application of limestone, lime mud, and gypsum in different doses and ways of applications, on a Humic Cambisol from Santa Catarina Plateau. The experiment was carried out with nine treatments in four replicates, where the evaluated parameters were determined up to 24 months after planting. In general, both limestone, lime mud, and gypsum, in different doses and ways of application, affected the chemical attributes of the soil but did not affect the foliar nutrient content at 12 months, height, and diameter at breast high (DBH) from trees and timber volume at 24 months. Gypsum do not correct soil acidity but lime mud provides similar results to limestone indicating that can substitute this corrective without damage to nutritional status and initial development of Eucalyptus dunnii

LIME AND GYPSUM APPLICATIONS ON SOIL CHEMICAL ATTRIBUTES AND INITIAL GROWTH OF EUCALYPTUS

Eucalyptus crops in Southern Brazil are generally conducted in acidic soils, thus their yield can be increased by lime and gypsum applications. The objective of this study was to evaluate the effect of lime and gypsum applications on soil chemical attributes and initial growth of Eucalyptus benthamii and Eucalyptus dunnii in a Humic Cambisol (Inceptisol). The experiment was conducted in a greenhouse, with seedlings of both species of eucalyptus grown in soil treated with different rates of lime (0, 3, 6, and 12 Mg ha-1), and gypsum (0, 6, 3, 12.6, and 25.2 Mg ha-1). At 90 days after application of the treatments, the soil chemical attributes and growth components of eucalyptus seedlings. The lime increased the production shoot dry weight, however, the response to gypsum was negative. The lime increased the soil pH, exchangeable calcium (Ca), base saturation (V %), and slightly the soil electrical conductivity, decreased the soil aluminium saturation (m %), and promoted little reduction in the exchangeable potassium (K) and magnesium (Mg) contents. The gypsum didn't alter the soil pH, but decreased the m%, increased soil phosphorus (P) contents, and expressively increased the electrical conductivity, which may have had a negative effect on the eucalyptus growth. In conclusion, the addition of limestone decreases the soil acidity and benefits the growth of eucalyptus seedlings. However, the addition of gypsum has no expressive effects upon those variables, but it can decrease the growth of seedlings when the rates are excessive.Eucalyptus crops in Southern Brazil are generally conducted in acidic soils, thus their yield can be increased by lime and gypsum applications. The objective of this study was to evaluate the effect of lime and gypsum applications on soil chemical attributes and initial growth of Eucalyptus benthamii and Eucalyptus dunnii in a Humic Cambisol (Inceptisol). The experiment was conducted in a greenhouse, with seedlings of both species of eucalyptus grown in soil treated with different rates of lime (0, 3, 6, and 12 Mg ha-1), and gypsum (0, 6, 3, 12.6, and 25.2 Mg ha-1). At 90 days after application of the treatments, the soil chemical attributes and growth components of eucalyptus seedlings. The lime increased the production shoot dry weight, however, the response to gypsum was negative. The lime increased the soil pH, exchangeable calcium (Ca), base saturation (V %), and slightly the soil electrical conductivity, decreased the soil aluminium saturation (m %), and promoted little reduction in the exchangeable potassium (K) and magnesium (Mg) contents. The gypsum didn't alter the soil pH, but decreased the m%, increased soil phosphorus (P) contents, and expressively increased the electrical conductivity, which may have had a negative effect on the eucalyptus growth. In conclusion, the addition of limestone decreases the soil acidity and benefits the growth of eucalyptus seedlings. However, the addition of gypsum has no expressive effects upon those variables, but it can decrease the growth of seedlings when the rates are excessive

Aporte de serapilheira e nutrientes ao solo em povoamentos jovens de Eucalyptus no planalto catarinense

Litter deposition and decomposition of litter may vary with age and, during the year, with climatic seasons. The objective of this study was to quantify the litter produced and the transfer of nutrients to the soil throughout the year in young stands of Eucalyptus dunnii Maiden. Field experiments were carried out over an Haplumbrept, in Bocaina do Sul, Santa Catarina State, Southern Brazil, with one, two and three year-old stands Three plots were installed int each plantation age, in order to collect plant litter. Litter sampling was performed monthly, during the entire year of 2011. It was used 11 collectors of 0.25 m² in each plot. It was quantified the deposition of dry matter of each component of litter (leaves, branches and bark) over the seasons, and determined the levels of P, S, K, Ca and. The three stands showed similar annual litter depositions, and about 95% of the total was constituted by leaves. Litter deposition presented seasonality, with the lowest deposition in the winter and the highest in the summer. Litter deposition was seasonal, with lower deposits in winter and higher in summer 99% P, 97% K, 97% Ca, 96% Mg and 98% S. The magnitude of values was: Ca > K > Mg > S > P.A deposição e decomposição de serapilheira em ecossistemas florestais pode variar com a idade e no decorrer do ano. Este trabalho tem por objetivo avaliar a deposição de serapilheira e quantificar a transferência de nutrientes ao solo ao longo do ano em povoamentos jovens de Eucalyptus dunnii Maiden. O estudo foi conduzido em Bocaina do Sul, SC, sobre um Cambissolo Húmico. Os tratamentos consistiram de avaliações em povoamentos de um, dois e três anos de idade. Em cada povoamento foram instaladas três parcelas e realizadas coletas mensais da serapilheira, utilizando 11 coletores de 0,25 m2 em cada parcela. Foi quantificada a deposição de matéria seca de cada componente da serapilheira (folhas, ramos e casca), e determinado os teores de P, S, K, Ca e Mg. Os três povoamentos apresentaram deposições anuais semelhantes de serapilheira, sendo cerca de 95% da biomassa representado pelas folhas. A deposição de serapilheira foi sazonal, com menor deposição no inverno e maior no verão. As folhas foram o principal contribuinte na transferência de nutrientes, transferindo em média 99% do P, 97% de K, 97% de Ca, 96% de Mg e 98% de S. A magnitude de transferência de foi: Ca > K > Mg > S > P

Alterações no carbono orgânico do solo de campo natural submetido ao plantio de Pinus taeda em três idades

Pine plantations on former natural grassland (NG) areas can change the forms and stocks of organic carbon (OC) in the soil. To quantify these changes, the contents and stocks of the total OC (TOC), consisting of particulate OC (POC) and the mineral-associated OC (MAC) fractions, were determined in fve layers, at depths between 0.0 and 0.40 m, in soil under NG and pine plantations aged fve (P5), 16 (P16) and 21 (P21) years. The study was carried out in areas of Cambissolo Húmico, dystrophic, on the southern plateau of Santa Catarina state. The TOC content in the different layers and under different land uses ranged from 15.0 to 44.5 g kg-1 and the TOC stock, in all layers together, from 86 to 144 Mg ha-1. The POC content varied from 2.1 to 23.2 g kg-1 and the POC stock from 7.4 to 21.8 Mg ha-1, while the MAC content varied between 12.2 and 23.7 g kg-1 and MAC stock between 79 and 122 Mg ha-1. In general, the TOC stocks and contents and MAC and POC fractions in the soil increase with the age of the pine plantations up to 21 years. The TOC and POC contents and POC stock usually decrease with depth under NG, P5 and P21, whereas the MAC content and MAC and TOC stocks generally remain unchanged in layers to a depth of 0.40 m.O plantio de pinus em áreas de campo natural (NG) pode alterar as formas e estoques de carbono orgânico (CO) do solo. Visando quantificar essas alterações, foram determinados os teores e estoques de CO total (TOC) e das frações particulada (POC) e associadas aos minerais (CAM) em cinco camadas, entre 0,0 e 0,4 m de profundidade, do solo sob usos com NG e plantios de pinus aos cinco (P5), 16 (P16) e 21 (P21) anos. O estudo foi realizado em áreas de Cambissolo Húmico na região do planalto sul de Santa Catarina. O teor de TOC, nas diferentes camadas e usos, variou entre 15 e 45 g kg-1 e seu estoque, na soma das camadas, entre 86 e 144 Mg ha-1. O teor de POC variou entre 2 a 23 g kg-1 e seu estoque, entre 7,5 e 22 Mg ha-1, enquanto o teor de CAM variou entre 12 e 24 g kg-1 e seu estoque, entre 78 e 122 Mg ha-1. Em geral, os teores e estoques de TOC e das frações CAM e POC do solo aumentam com a idade dos plantios de pinus até 21 anos. Os teores de TOC e POC e o estoque dessa fração, em geral diminuem com a profundidade do solo sob NG e P5 e P21, mas o teor de CAM e os estoques dessa fração e do TOC geralmente não variam entre as camadas até 0,40 m de profundidade

Modelagem estocástica: previsão das temperaturas para a localidade de Pelotas/RS/Brasil.

O conhecimento da temperatura do ponto de vista agronômico é importante para o crescimento e desenvolvimento das plantas, assim como para a produção agrícola. No entanto, nem sempre tem-se a disponibilidade de séries temporais, de forma que caracterize o comportamento da variável de interesse ao longo do tempo. Nesse sentido, objetivou-se modelar as séries de temperaturas médias mínima, máxima e média anual da estação agroclimatológica localizada em Pelotas, RS, Brasil, no período de 1931 a 2011, utilizando os modelos autorregressivos e, a partir da adequação do modelo selecionado, realizar a predição da variável. Para tanto foram utilizados os testes de Cox-Stuart, Wald-Wolfowitz, Spearman e Mann-Kendall, para comprovar ou não, a existência de tendência das séries de temperatura ao longo do tempo. Para a modelagem foram utilizados os modelos Autorregressivos Integrados Média Móvel e, para a seleção do modelo mais adequado, o teste de Porteau Monteau. O teste não-paramétrico de Spearman foi considerado o mais robusto para a detecção de tendência nas séries temporais, o que permitiu observar um acréscimo de 1,12ºC nas temperaturas médias mínimas anuais da localidade em estudo. As temperaturas médias mínimas anuais de Pelotas, RS, podem ser previstas pelos modelos autorregressivos – AR (1), cuja inclusão de outro parâmetro regressivo não apresentou ganho de informação na previsão das mesmas

Extração e fitodisponibilidade de metais em resposta à adição de lodo de esgoto no solo

To evaluate environmental risk of sludge application in agriculture, a greenhouse experiment was carried out in Piracicaba, SP, Brazil, to compare the efficiency of extractors in the availability of heavy metals to plants, in soil treated with sewage sludge. The effect of the sludge was also evaluated combined or not with P, K and PK, on the accumulation of metals in the shoot. Soil samples, collected from the 0-20 cm layer of a Typic Hapludalf were placed in pots and mixed with 0, 10, 20, 30, 40 and 50 Mg ha-1 (dry-basis) of sludge. Thirty days after incubation, soil samples were taken from each pot for determination of Fe, Mn, Cu, Zn, Cd, Ni, Cr and Pb (extracted by HCl 0.1 mol L-1, Mehlich-3 and DTPA pH 7.3). Two Rates of phosphate as were applied (0 and 100 Mg ha-1) as well as two rates of potassium (0 and 100 Mg ha-1). Maize (Zea mays L.) plants were grown for 50 days, collected and submitted to heavy metal determination. The application of sewage sludge increased the amounts of Fe, Mn, Cu and Zn accumulated in plants, whereas the addition of potassium increased dry matter yield and decreased the accumulation of Zn. The pH reduction and soil native metal influenced the availability of Mn. All extractors were efficient in predicting the Zn and Cu availability to plants. For Mn and Fe the most efficient solutions were: HCl and Mehlich-3, HCl and DTPA, respectively. For the other metals, none of the extractors was efficient.Diante dos riscos ambientais relacionados ao uso agrícola de lodo de esgoto contendo metais foi realizado um experimento, com o objetivo de avaliar o efeito do lodo, combinado ou não com P, K e PK, sobre o acúmulo de metais na parte aérea das plantas e comparar a eficiência de extratores na fitodisponibilidade de metais. Amostras da camada de 0-20 cm de um Argissolo Vermelho Amarelo eutrófico foram transferidas para vasos e tratadas com doses equivalentes a 0, 10, 20, 30, 40 e 50 Mg ha-1 de lodo (base seca). Após 30 dias de incubação, determinou-se os teores de Fe, Mn, Cu, Zn, Cd, Ni, Cr e Pb (extraídos por HCl 0,1 mol L-1, Mehlich-3 e DTPA pH 7,3), procedeu-se aplicação de duas doses de P (0 e 100 mg kg-1) e duas dose de K (0 e 100 mg kg-1). Cultivaram-se plantas de milho (Zea mays L.) durante 50 dias, coletando-se a parte aérea para determinação de metais. A aplicação de lodo aumentou o teor de Fe, Mn, Zn e Cu no solo e o acúmulo pelas plantas, enquanto a complementação do resíduo com potássio aumentou a produção de matéria seca e diminuiu o acúmulo de Zn. A redução do pH e o Mn nativo do solo influenciaram no aumento da disponibilidade Mn. Todos os extratores foram eficientes para predição da fitodisponibilidade de Zn e Cu. Para o Mn e Fe, os mais eficientes foram: HCl e Mehlich-3, HCl e DTPA, respectivamente. Para os demais metais, os extratores se mostraram pouco eficientes