Nutrição mineral da seringueira III: ciclagem de nutrientes em um seringal na região de Rio Branco, AC

Leaves, systems and branches from trees of one year up to four years were collected from a plantation located at the BONAL S/A in Rio Branco, AC, Brazil the soilunder the plantation is classified as Red-yellow Latossol. Samples of the leguminous (Pueraria phaseoloides) and liter were also collected in order to estimate the total amounts of nutrients extracted and the cycling of the nutrients in the system. The results obtained showed that: - The dry matter produced (3,185 kg/ha) by the leguminous at 48 months is much greater than that produced by the rubber trees (2,787 kg/ha) at the same age. - The dry matter produced by the liter (5,912 kg/ /ha) is also greater than that produced by the rubber trees . - The total amount of nutrients content in the leguminous at 48 .months is estimate in 164 kg/ha in the rubber trees is approximate in 57 kg/ha. - The total amount of nutrients content in the mulch covering the soil at 48 months is estimate in 196 kg/ha. From the total amounts of nutrients extracted from the soil by the rubber trees and the leguminous at 48 months the following porcentage in nutrients return to the soil: K-21.7%; P-37.3%; S-51.2%; Zn-51.8%; Mg-54.4%; B-54.7%; Ca-56.4%; Cu-57-5%; N-58.5%; Mn-74.5% and Fe--90.7%.Com a finalidade de quantificar a ciclagem de nutrientes em uma plantação de seringueira, situada em um Latossolo Vermelho Amarelo textura argilosa, localizada na região de Rio Branco AC, amostras da cobertura morta (Pueraria phaseoloides), cobertura mista de plantas de seringueira de 1 a 4anos de idade foram coletadas secas, pesadas e analisadas para N, P, K, Ca, Mg, S, B, Cu, Mn e Zn. Os autores observaram que a produção de matéria seca proveninente da leguminosa e da cobertura morta aos 36 e 48 meses superou a produção da matéria seca produzida pela leguminosa. A quantidade de nutrientes contidos na leguminosa e na cobertura morta supera em larga margem o contido na seringueira. A extração total de nutrientes pelo sistema para os nutrientes em ordem decrecente doi: N >; K >; Ca >; Mg >; S >; P, enquanto que para os micronutrientes a ordem foi: Fe >; Mn >; Zn >; B >; Cu. Os autores alertam pela necessidade de se manter a ciclagem de nutrientes nas plantações de seringueira, a fim de não diminuir a produção de latex

Nutrição mineral da seringueira: II. Recrutamento de micronutrientes no período de quatro anos na região de Rio Branco, AC

Primary objective of this work was to study concentration and accumulation of the micronutrients on the rubber plants, at variuns ages. Leaves, stems and branches from one year up to four years old were collected from a plantation located at the BONAL S.A. farm at Rio Branco, Brazil. The soil under the forest was classified as a heavy texture Red-Yellow Latossol. The results showed: The leaves had the highest nutrient concentration, with the exception for copper and zinc. During the fourth year, nutrient extraction per hectare was: 29.4 g B; 18.3 g Cu; 140.4 g Fe; 436.7 g Mn and 52.2 Zn. Total micronutrients were absorbed in the following decreasing order: Fe >; Mn >; Zn >; B >; Cu.Com o objetivo de obter dados referentes a concentração e acúmulo de micronutrientes em função da idade da planta, foram coletadas amostras de folhas, galhos secos, ponta e base de galhos primários, e ponta, meio e base do tronco de plantas de seringueira clone Fx 3864 com 1 a 4 anos de idade situadas sobre Latossol Vermelho-Amarelo, textura argilosa na área da BONAL S.A. localizada na região de Rio Branco, AC Os resultados mostraram que: 1. As maiores concentrações de nutrientes ocor rem nas folhas com exceção do cobre e zinco; 2. A extração de nutrientes por hectare no quarto ano foi de: B-29,4 g, Cu-18,3 g, Fe - 140 g, Mn - 437,7 g e Zn - 52,2 g; 3. A extração total de nutrientes, em ordem decrescente foi: Fe Mn Zn B Cu

Estudos sobre a nutrição mineral do sorgo sacarino (Sorghum bicolor (L) Moench) cv. Brands. II: absorção e redistribuição do radiofósforo

This paper deals with the following aspects of the phosphatic nutrition of sweet sorghum: absorption of radiophosphate as influenced by time of uptake and external concentration; comparative foliar absorption of monoammonium and diammonium phosphate both in the presence and absence of urea; redistribution of previously absorbed and stored phosphate. Data obtained herewith allowed for the following conclusions to be drawn: (1) root absorption increased with time of contact, being higher in the case of excised when compared to roots in intact plants; (2) Michaelis and Menten kinetics are applicable to root uptake, the parameters being different for the two types of root material; (3) the two ammonium phosphates showed the same rate of uptake, which was not influenced by urea; (4) P deficient plants showed highes rates of uptake and translocation.Foi estudada a absorção radicular do radiofósforo sob influência do tempo de contato com a solução e da concentração externa. Foi também estudada a absorção foliar dos fosfatos mono e diamônico isolados e em presença de uréia. A redistribuiçao do P absorvido pelas raízes foi acompanhada através do fracionamento das formas de fósforo nos diversos órgaos da planta analisadas em diferentes períodos

Estudos sobre a nutrição mineral do arroz: XI. Marcha de absorção de micronutrientes pela variedade IAC-47

Dry matter yield and uptake of B, Cu, Fe, Mn and Zn by the rice variety IAC-47 were studied under controlled conditions, namely, by growing plants in nutrient solution and by falcing samples for analyses in set physiological periods. It was observed that only the curves describing dry matter production and accumulation of B and Fe was verified.A produção de matéria seca e a absorção de micronutrientes (B, Cu, Fe, Mn e Zn) pelo arroz var. IAC-47 foram estudadas usando-se plantas cultivadas em solução nutritiva. Verificou-se que: enquanto as curvas que descrevem o crescimento e a acumulação de B e Fe mostram tendência sigmóide, as demais não o fazem, evidência de redistribuição foi observada somente nos casos do B (diminuição no conteúdo foliar) e no do Fe (diminuição no conteúdo da raiz)

Estudos sobre a nutrição mineral do arroz: VII. exigências nutricionais das variedades IAC-25 e IAC-47

Rice plants, varieties IAC 25 and IAC 47, were grown in nutrient solution till the end of the life cycle when they were analysed both for macro and micronutrients. Main conclusions were the following: IAC 47, higher yielding, showed larger requirements than IAC 25; for production (total) and export (grain), the demand for nutrients was the same in both varieties.As exigências nutricionais das variedades de arroz IAC 25 e IAC 47 foram determinadas analisando-se os diferentes órgãos de plantas cultivadas em solução nutritiva até o fim do ciclo. Verificou-se serem distintas as exigências, maior na IAC 47 (mais tardia) que deu também maior produção de grãos com casca

Studies on the mineral nutrition of the rice plant: IX. time course on the uptake of macronutrients by the variety IAC-47

Rice plants, variety IAC-47, were grown in the nº 2 nutrient solution of HOAGLAND & ARNON (1950) until the end of the life cycle. Plants were sampled at well defined physiological periods for analyses. It was verified that trends for levvelling off occurred in the case of accumulation of N, K and Ca. Translocation from leaves to grain was observed with respect to N, P and K. Maximum rates of uptake of all elements took place from 50 to 100 days after germination.Foram estudadas, em condições controladas, a acumulação de matéria seca e a de macronutrientes na variedade de arroz IAC-47. Ambos os processos em geral são descritos por sigmóides típicas; picos para os valores totais de produção de matéria seca e de acumulação de elementos entre: 100 e 140 dias depois da germinação

Description of diffusive and propagative behavior on fractals

The known properties of diffusion on fractals are reviewed in order to give a general outlook of these dynamic processes. After that, we propose a description developed in the context of the intrinsic metric of fractals, which leads us to a differential equation able to describe diffusion in real fractals in the asymptotic regime. We show that our approach has a stronger physical justification than previous works on this field. The most important result we present is the introduction of a dependence on time and space for the conductivity in fractals, which is deduced by scaling arguments and supported by computer simulations. Finally, the diffusion equation is used to introduce the possibility of reaction-diffusion processes on fractals and analyze their properties. Specifically, an analytic expression for the speed of the corresponding travelling fronts, which can be of great interest for application purposes, is derived

Estudos sobre a nutrição mineral do arroz: XIII. efeitos das deficiências de micronutrientes nas variedades IAC-25 e IAC-47

Rice plants were grown in nutrient solution lither in the presence or in the absence of B, Cu and Zn. The symptoms of deficiency were usually in agreement with those described in the literature. Growth of the variety IAC-47 (number of leaves, tillering and total dry matter) was relatively more affected; this variety, however did produce grains under the minus Cu treatment (one fourth of the yield observed in the "complete" treatment), which did not happen in the case of the other variety. At the beginning of the grain filling period the following leaf contents could be considered as indication of deficiency: B-13 to 25 ppm; Zn-20 ppm; no conclusion could be drawn with respect to Cu levels.Plantas de arroz, variedades IAC-25 e IAC-47 foram cultivadas em solução nutritiva e com deficiência de B, Cu e Zn. Foram obtidos sintomas de carência dos três micronutrientes. As deficiências induzidas provocaram diminuição na matéria seca total e no número de folhas das duas variedades. O mesmo ocorreu no numero de perfilhos da var. IAC-47. Foi feita a determinação dos teores dos micronutrientes nas plantas submetidas aos diferentes tratamentos o que forneceu dados que ajudam a avaliação do estado nutricional