RESPOSTA DO ÁLAMO (Populus deltoides Marsh) À ADUBAÇÃO NITROGENADA EM DOIS SÍTIOS DO MUNICÍPIO DE SÃO MATEUS DO SUL, PARANÁ

Os plantios de álamo realizados na região de São Mateus do Sul, PR, não tem o desenvolvimento esperado, pela ausência de informações a respeito de clones ideais, pragas, doenças e nutrição. Diante da carência de estudos sobre fertilização de povoamentos de álamo para as condições em que a espécie é plantada no Brasil e visando a melhorar a produtividade dos plantios de álamo na região de São Mateus do Sul, PR, foi instalado um experimento testando cinco doses de N e mais um formulado NPK em dois sítios diferentes. As avaliações mostraram um pequeno efeito da adubação sobre o crescimento em circunferência à altura do peito (CAP) e altura total (Ht). Também houve correlação positiva entre os parâmetros de crescimento com P, Ca e pH do solo, e os teores de P, Ca e B da folha, indicando a influência desses elementos sobre o crescimento das plantas, sugerindo a necessidade de adequação da fertilidade do solo, via corretivos da acidez e adubação, antes da implantação das mudas

SOIL CHEMICAL ATTRIBUTES AND THEIR INFLUENCE ON ELEMENTAL COMPOSITION OF YERBA MATE LEAVES

Yerba mate (Ilex paraguariensis St. Hil.) is a raw material used in making a beverage whose chemical composition can be altered by the growing environment and the management adopted during its cultivation. Thus, it is essential that scientific studies are undertaken to understand the chemical composition of yerba mate related to its growing environment. The aim of this work was to determine the elemental composition in the leaves of yerba mate from native cultivations that had never received fertilization and liming, from the Southern Region of the state of Paraná, Brazil. Soil and leaf samples were collected at 11 sites located in the municipalities of São Mateus do Sul, Mallet, São João do Triunfo, and Lapa. Leaf analyzes were performed in an Optical Emission Spectrometer with Inductively Coupled Plasma. The mean concentrations observed (mg kg-1), in decreasing order, were: Ca – 7880; K – 7310; Mn – 2418; - Mg – 820; P – 720; Al – 474; Fe – 231; B – 78; Zn – 62; Ba - 62; Cu – 8.9; Ni – 5.6; Cr – 0.82; V – 0.53; Co – 0.17. The Mn concentrations were directly correlated with Al3+ saturation and inversely correlated with base saturation, pH, and the available Ca2+, demonstrating that changes among these soil components can significantly modify the Mn concentrations in the yerba mate leaves. The high concentrations of Mn and Al in the leaves of yerba mate demonstrate the adaptation of this species to acidic soils with high saturation of Al3+.Yerba mate (Ilex paraguariensis St. Hil.) is a raw material used in making a beverage whose chemical composition can be altered by the growing environment and the management adopted during its cultivation. Thus, it is essential that scientific studies are undertaken to understand the chemical composition of yerba mate related to its growing environment. The aim of this work was to determine the elemental composition in the leaves of yerba mate from native cultivations that had never received fertilization and liming, from the southern region of the State of Parant, Brazil. Soil and leaf samples were collected at 11 sites located in the São Mateus do Sul, Mallet, São João do Triunfo, and Lapa municipalities. Leaf analyzes were performed in an Optical Emission Spectrometer with Inductively Coupled Plasma. The mean concentrations observed (mg kg-1), in decreasing order, were: Ca – 7880; K – 7310; Mn – 2418; - Mg – 820; P – 720; Al – 474; Fe – 231; B – 78; Zn – 62; Ba - 62; Cu – 8.9; Ni – 5.6; Cr – 0.82; V – 0.53; Co – 0.17. The Mn concentrations were directly correlated with Al3+ saturation and inversely correlated with base saturation, pH, and the available Ca2+, demonstrating that changes among these soil components can significantly modify the Mn concentrations in the yerba mate leaves. The high concentrations of Mn and Al in the leaves of yerba mate demonstrate the adaptation of this species to acidic soils with high saturation of Al3+

Biomass and phosphorus content in giant bamboo cuttings influenced by phosphate fertilization

Dendrocalamus asper, known as giant bamboo or bamboo-bucket, has been used as a substitute for wood and fiber, due mainly to its wide availability, rapid growth rate, short cycle and traditional use as construction material. In general, its cultivation is carried out on phosphorus-deficient soils, using vegetative propagation, mainly from cuttings. Thus, the aim of this study was to evaluate the effect of fertilization with phosphorus doses on the biomass allocation in roots, leaves and stems and on the level and content of P in leaves and roots of bamboo cuttings. The experiment was conducted in a greenhouse, using soil with low P content (2.4 mg dm-3). The treatments consisted of six doses of phosphorus (0, 20, 40, 80, 160 e 320 kg ha-1 of P2O5). The experimental design was a randomized block design, with five replications. After 90 days, the seedlings were collected and evaluated the following variables: dry mass of roots, leaves, stems and total dry mass, level and P content in leaves and roots. Phosphate fertilization promoted greater development of the cuttings and resulted in higher content of P. In general, the species D. asper responds positively to phosphate fertilization

Efeito de fontes e doses de acidificantes no pH do solo coletado do piso de galinheiros

A acidificação de resíduo de animais vem sendo uma das maneiras de combater proliferação de bactérias e a alta volatilização de amônia (NH3). No Brazil, contrariamente, procede a alcalinização com óxidos básicos com elevação do pH da cama e solo do piso dos aviários, criando neste último uma fonte constante de contaminação. Neste sentido, este estudo teve como objetivo verificar o efeito de Bissulfato de sódio (SB) e enxofre elementar (ES) na acidificação de diferentes solos de aviário, quanto a eficiência e tempo de reação. Utilizou-se três solos coletados dentro de galpões de criação de frango (6, 36 e 60 meses de ocupação), além da coleta do solo externo ao aviário, totalizando quatro locais de amostragens. As duas fontes de acidificantes, o SB e o ES foram aplicadas em 6 doses crescentes (0, 2, 3, 6, 12 e 24 cmolc/kg de H+ na camada de 3 cm de solo), incubados até 53 dias. Ao final de cada período de incubação determinou-se o pH do solo. Os resultados do presente estudo permitiram concluir que o SB é eficiente na redução do pH do solo de aviário com reação imediata após sua aplicação. Nas condições do presente estudo a dose indicada de SB para reduzir o pH para 5,0 foi de 6 cmolc kg-1 H+ que correspondeu a aplicação de 7,2 g do produto em 500 g de solo. O ES elementar mostrou reação lenta e baixa eficiência. Acidificação do solo do aviário pode ser obtido rapidamente e eficientemente com uso de SB

Forage production and chemical composition of Trachypogon plumosus under soil fertility correction and defoliation levels

Foram avaliados os efeitos de níveis de correção da fertilidade do solo (testemunha, calagem, adubação e calagem + adubação), níveis de desfolhação (remoção de 50 e 75% da parte aérea da gramínea) e estações de crescimento (períodos chuvoso e seco) sobre a produtividade e composição química da forragem de Trachypogon plumosus nos cerrados de Roraima. A gramínea apresentou alta responsividade à melhoria do ambiente de produção, apesar de sua boa adaptação aos solos de baixa fertilidade de cerrados. O aumento da intensidade de desfolhação, durante o período chuvoso, reduziu as taxas de crescimento e a produtividade e qualidade da forragem, independentemente do nível de correção da fertilidade do solo, não sendo detectado efeito significativo (P>0,05) durante o período seco. Os maiores rendimentos de matéria seca verde (P0.05) during dry season. The highest yields of green dry matter (P<0.05) were recorded during the rainy season, with 50% defoliation and use of lime + fertilizer (6,607 kg ha-1) or fertilization (6,314 kg ha-1). The removal of 75% of pasture canopy in combination with lime + fertilizer (2,433 kg ha-1) or fertilization (2,335 kg ha-1), during the rainy season resulted in higher accumulation of dead material. The highest levels of nitrogen (N) and the lowest neutral detergent fiber (NDF) and acid detergent fiber (ADF) were estimated during the rainy season jointly with lime + fertilizer (16.22 g kg-1 of N; 71.89% of NDF and 34.11% of ADF) or fertilization (15.79 g kg-1 of N; 72.14% of NDF and 35.83% of ADF). The use of fertilizer and lime + fertilizer and defoliation level of 50% provided better seasonal distribution and higher productivity and quality of forage, besides the reduction in grazing interval

Forage accumulation and morphogenesis of trachypogon plumosus under different levels of nitrogen fertilization

O efeito da adubação nitrogenada (0, 50, 100 e 200 kg N ha-1) sobre o acúmulo de forragem e características morfogênicas e estruturais de Trachypogon plumosus foi avaliado nos cerrados de Roraima. O delineamento experimental foi em blocos casualizados com três repetições. A adubação nitrogenada proporcionou incrementos quadráticos na produção de matéria seca, teores de nitrogênio, taxas de aparecimento e alongamento foliar, número de folhas vivas/perfilho, comprimento final de folha e índice de área foliar, sendo os máximos valores estimados com a aplicação de 153,5 (2.849 kg ha-1); 124,0 (23,97 g/kg); 155,4 (0,155 folha perfilho-1 dia-1); 116,1 (2,64 cm dia-1 perfilho-1); 147,0 (6,43 folhas perfilho-1), 135,1 (19,04 cm) e 181,2 kg de N ha-1 (2,56), respectivamente. A densidade populacional de perfilhos e a taxa de senescência foliar foram diretamente proporcionais às doses de nitrogênio, ocorrendo o oposto quanto à eficiência de utilização e a recuperação aparente do nitrogênio.The effect of nitrogen fertilization (0, 50, 100 and 200 kg N ha-1) on forage production and morphogenetic and structural characteristics of Trachypogon plumosus was evaluated in the Roraima´s savannas. The experimental design was in randomized blocks with three replicates. Nitrogen fertilization promoted quadratic increase in the dry matter (DM) yield, nitrogen contents, leaf appearance rate, leaf elongation rate, number of live leaves/tiller, final leaf length and leaf area index; maximum values were estimated with application of 153.5 (2,849 kg ha-1); 124.0 (23.97 g/kg); 155.4 (0.155 leaf tiller-1 day-1); 116.1 (2.64 cm day-1 tiller-1); 147.0 (6.43 leaves tiller-1); 135.1 (19.04 cm) and 181.2 kg N ha-1, (2.56), respectively. Tiller population density and leaf senescence rate were directly proportional to nitrogen levels, and the opposite occurred for efficiency of utilization and apparent nitrogen recovery

Elemental composition of yerba mate (Ilex paraguariensis A.St.-Hil.) under low input systems of southern Brazil

© 2020 Elsevier B.V. Elemental composition of food can be used to determine nutritional potential as well as guiding legislation for establishing maximum acceptable limits (MAL) of metals in consumption products. This study aimed to determine the elemental background levels of yerba mate (Ilex paraguariensis A.St.-Hil.) under varied geologic formations in southern Brazil. Mature leaves were randomly collected from four wild-grown plants at thirty native sites in three states and analyzed for 32 elements. Since yerba mate is not washed to obtain the final product, leaves were analyzed with and without washing to assess foliar deposition. Concentration values of As, Ag, Be, Cs, Cr, Li, Se, Tl, U, and V were near detection limits, indicating low potential as a source and/or toxicity to the consumer. Washing decreased concentrations of Fe, Ti, As, Mo, Li, V, and Pb, suggesting atmospheric contributions/dust deposition. Concentrations of Mn (very high), Zn (high), and Ni (high) demonstrated that leaves could be an important source of these elements. Soil parent material affected elemental composition with basalt providing higher concentrations of Mn, P, and Co while Rhyodacite provided higher concentrations of K and Na. All samples exhibited Pb values below the MAL of 0.6 mg kg−1, but 23% of washed leaves and 20% of unwashed leaves had Cd concentrations close to or above the MAL value of 0.4 mg kg−1. Study results indicated that Cd MAL values for yerba mate in southern Brazil should be reassessed

Elemental signatures of an Amazonian Dark Earth as result of its formation process

© 2019 Elsevier B.V. Amazonian Dark Earths (ADEs) are soils studied for archaeological purposes and as a potentially agricultural model for the humid tropic. We investigated the chemical composition of an ADE in comparison to an adjacent Ultisol without anthropic influence for better understanding the origin of ADE fertility and formation process. Three hundred ADE and Ultisol samples were collected at 10 cm depths from 0 to 100 cm soil profiles on the Caldeirão site at the Solimões River, Brazil and analyzed for elemental composition in an inductively coupled plasma mass spectrometer (ICP-MS). Results showed significantly increased concentrations of P, Ca, K, Mg, Mn, Ba, Zn, Sr, Cu, Rb, Ni, Li, Cd, Cs, Co, Tl, and Be and reduced concentrations of Se along the ADE profile relative to the control Ultisol. Additionally, it was also detected reduced concentrations of Al, U, and V in ADE superficial layers. Elemental enrichment factors in ADE varied from 1.6 to 15.9 times and the enriched elements have mostly been associated with organic residues. Besides the common elements used to characterize ADE sites, our results have shown altered concentrations of other uncommon elements (Al, Be, Cd, Cs, Li, Se, Tl, U, and V) that can be also used to unveil ADE sites and differentiate them from Amazonian soils without anthropic influence