Dinâmica do potássio no solo e nutrição potássica da soja

Potassium deficiency in soybeans has spread iii São Paulo State, Brazil, as a consequence of soil K reserve depletion. Exchangeable and nonexchangeable K dynamics in soil were investigated in order to understand the reserve exaustion and its significance to soybean nutrition. Soybean was grown in 8 1 pots with five soils differing in K and clay contents, in presence or absence of K fertilization. Soil samples were taken at 20 days interval and soybean was harvest at R6. Exchangeable (H2SO4 0,05 N) and nonexchangeable K (boiling HNO3) were estimated in soil sample. Two of the soils were very poor in exchangeable K, and even so there was no response in dry matter due to K fertilization. In spite of some differences in K contents in some of the soybeans parts, generally K absorption was not affected by K fertilization, except in grains. Potassium acumulation in soybean plants were affected by soils, but the response was not closely related to exchangeable K in soil. The main K source to the plants was the HNO3 extrated K, showing that this form is not at all nonexchangeable. After the period of maximum plant demand there was a sharp increase in extractable K in soil showing a tendency to a natural equilibrium.

Manganês no solo, sua avaliação e toxidez de manganês em soja

Two experiments were carried out in pots with a Dusky Latossol showing a 15% base saturation. In the first experiment dolomitic limestone was applied to reach 45, 60, 75 and 90% of base saturation. In the second, MnSO4 was applied in rates of 30, 60, 90 and 120 ppm,and base saturation was raised to 70%.Soybean plants cv. IAC-9 were grown up to R6, when dry matter production and manganese accumulation were evaluated. Soybean responded to liming up to 60% base saturation, as Mn availability and evantualy Mn absorption were decreased to non-toxic levels. Mn applied to a reclamed soil up to 120 ppm was not enough to cause toxicity to soybean cv IAC-9. All of the chemical extractors (Ammonium Acetate, DTA, Mehlich and H2SO4) showed modification in Mn availabity in soil but were not definitely related to Mn absorption and dry matter production.

Características químicas do resíduo do leite de soja obtido a partir do farelo e da farinha do grão integral de soja

O objetivo do presente trabalho foi estudar os efeitos de diferentes tempos de processamento (duas, quatro e seis horas) e temperaturas (50°C, 65°C e 80°C) em dois substratos: farinha do grão integral de soja e farelo de soja. Para obtenção do resíduo, utilizou-se uma máquina de aço inoxidável com termostato para controle de temperatura e agitador constante. O delineamento estatístico utilizado na análise dos dados foi inteiramente casualizado, segundo o esquema fatorial 3 x 3 x 2 com duas repetições. Concluiu-se que os tratamentos não apresentaram diferenças marcantes na composição química e mineral do resíduo. O teor de proteína no resíduo do farelo foi 3,5% superior ao teor do farelo que lhe deu origem, o contrário ocorreu com o resíduo da farinha que foi 9,8% inferior. O teor de extrato etéreo no resíduo da farinha, aproximou-se bastante do teor da farinha do grão integral (21,41%) e no resíduo do farelo foi ligeiramente inferior.

Deficiência de Mn em soja, induzida por adubação potássica e calagem

Tanto a toxidez como a deficiência de Mn em soja (Glycine max (L.) Merrill), levam a um prejuízo na produtividade. Tem-se recomendado a calagem para superar os graves problemas de toxidez de Mn em soja, mas existem condições potenciais para ocorrer indução de deficiências de micronutrientes, inclusive o Mn. Com o objetivo de explorar esta possibilidade, a cultivar de soja Cristalina foi plantada em vasos, contendo dois Latossolos Vermelho- Escuro de textura média, na presença ou ausência de adubação potássica (50 ug/cm3), e calagem. Os resultados obtidos demonstraram que a adubação potássica pode ter como consequência uma menor absorção de Mn pela soja, e quando associada à calagem (pH 6,5) pode levar à ocorrência de deficiência induzida de Mn, que se manifesta como clorose internerval nas folhas do terço superior da planta.

Influência da utilização da proteína texturizada de soja nas características sensoriais, químicas e funcionais e de processamento do fiambre de frango

This research was designed to study the effect of addition of 5, 10 e 15% of textured soy protein (TSP) on sensorial, chemical, and physical-chemical parameters of chicken loaf with ground meat. The sensorial properties were not affected by textured soy protein. The addition of textured soy protein in preparing chicken loaf increased the water absorption and holding capacity, and decreased the moisture and ether extract content, but did not increase the final product yield.

Adubação potássica da soja em latossolo vermelho-escuro fase arenosa

Durante três anos foi conduzido um experimento em Latossolo Vermelho-Escuro fase arenosa, no qual foram estudados os efeitos de adubações anuais com 0,40, 80, 160 e 240 kg/ha de K2O, nas formas de cloreto de potássio e sulfato de potássio, aplicados no sulco de semeadura ou em área total com incorporação. Observou-se resposta à adubação potássica a partir do segundo ano de cultivo. As máximas produções sempre estiveram associadas a teores de potássio nas folhas acima de 1,5%. Em anos mais secos que o normal, as aplicações a lanço proporcionaram melhores resultados do que as aplicações em sulcos. Não foram observadas diferenças entre as fontes de potássio utilizadas. Notou-se acentuado decréscimo nos teores de potássio trocável do solo, com o transcorrer do tempo, sendo necessária a aplicação de doses maiores que 80 kg/ha de K2O por ano para manter o nível original. Por outro lado, a aplicação de doses elevadas de potássio levou a uma perda significativa do nutriente por lixiviação.

Diferentes resposta de cutivares de soja e potássio

Soybean (Glycine max (L.) Merrill) is known to have a high ability as a potassium extractor, and different cultivars show different potassium requirements. An experiment was run to study the potassium nutrition of soybean as related to plant characteristics. Six soybean cultivars (FT-2, Bossier, IAC-11, IAC-17, IAC-18 and IAC-19) were grown in 6 kg pots filled with the topsoil of a Dark Red Latosol (sandy loam), either with and without K fertilization. The plants were harvested 70 days after emergence. Soybean response to potassium was not related to growth habit or group of maturation. There was a different response to K. The cultivars IAC-18 and FT-2 were less tolerant to K deficiency. Potassium deficiency in the leaves was not related to top dry matter production. With K fertilization soybean plants showed small root volume and higher ratio canopy/root. With high K in soil, all of the cultivars showed higher nodulation.

Condutividade elétrica na solução de embebição de sements de soja. I. Efeito do genótipo

During the period from October/92 to September/94 experiments were carried out at the Seed Laboratory, FCAV/UNESP, Jaboticabal, SP, Brazil, using soybean seeds of different genotypes in order to evaluate the effect of genotype on the electrical conductivity (bulk conductivity) of soaked seeds. Seed moisture content (105+/-3 degrees C, 24 h), standard germination (four 50-seed samples, paper towel, 30 degrees C), and vigor-accelerated aging (42 degrees C, 48 h) were first determined. Undamaged soybean seeds were soaked in deionized water (four 50-seed samples, 75 ml, 25 degrees C, 24 h) and electrical conductivity (mu mhos.cm(-1).g(-1)) was measured. Significant differences in conductivity were observed among genotypes having the same pattern of germination and vigor. The results have showed that electrical conductivity can be significantly influenced by genotype.

Épocas de semeadura da soja I. Efeitos na produção de grãos e nos componentes da produção

O presente trabalho foi realizado como objetivo de estudar os efeitos de épocas da semeadura na produção de grãos e nos componentes de produção de três cultivares de soja (Glycine max (L.) Merrill) de ciclos culturais distintos. Os experimentos foram desenvolvidos em campo, no município de Botucatu, Estado de São Paulo (latitude 22º 51 'S e longitude 48º 27'W.Grw.), em solo classificado como Terra Roxa Estruturada, durante os anos agrícolas de 1977/78, 1978/79 e 1979/80. As cultivares empregadas foram Paraná, Santa Rosa, UFV-1. As semeaduras, em número de seis, foram realizadas com intervalos, aproximadamente, quinzenais, com início de semeadura em outubro. Foram avaliados: a produção de sementes (kg/ha), número de vagens/planta, percentagem de vagens normais e peso de 100 sementes. As maiores produções de grãos, para as três cultivares, foram obtidas nas semeaduras realizadas na segunda quinzena de outubro e durante o mês de novembro. O número de vagens por planta e o peso de 100 grãos foram os componentes da produção que mais sofreram efeitos das épocas de semeadura.

Efeitos nutricionais da substituição parcial do farelo de soja por uréia, em dieta de ovinos. Comparação da digestibilidade aparente e balanço de nitrogênio com a cinética do metabolismo da 15N-glicina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desempenho produtivo de alevinos de tilápia-do-nilo (Oreochromis niloticus) arraçoados com farinha de soja

This experiment was carried out in the Research Laboratory on Nutrition of Aquatic Organisms, Aquaculture Center UNESP, FMVZ - Botucatu, SP, Brazil. The study aimed to evaluate the effect of raw full-fat soybean meal on feeding in fingerlings of the Nile tilapia (Oreochromis niloticus). The suitable level of consumption of raw full-fat soybean meal (RSM) was determined by means of productive performance. The experimental design was a Multivariate Profile Analyses, with four treatments (four replicates each one). Each isoproteic (26% CP) and isoenergetic (3000 Kcal ME/ kg) diet received raw full-fat soybean meal at 6.0%, 12.0% and 18.0%. A treatment without soybean meal was used as control. Forty eight fingerlings with similar size (mean Wt ± SD: 6.47 ± 0.64 g; and mean Lt ± SD: 54.94 ± 7.79 mm) at the beginning of the experiments were used. No significant difference (p>0.05%) in weight gain among the four treatments was found. However, the treatments with 12.0 and 18.0% RSM showed a reduction in the coefficient of digestibility in these treatments. This shows a deleterious effect of the raw full-fat soybean meal at these considered levels (12.0% and 18.0% RSM).

Substituição do farelo de soja pelo de guandu na alimentação de frangos de corte

The objective of this work was to evaluate the nutritive value of pigeon pea meal (PPM) with methionine substituting soybean meal (SM) in diets for 1-28 day-old broiler chicks. The experimental design was that of random blocks, in a 3 × 3 factorial scheme with three substitution levels - 15,30 and 45% - and three methionine supplementation levels in relation to the requirements, that is: 100, 66 and 33%, with four repetitions. It was found that PPM treated for 20 minutes at 100°C substituted up to 30% of the SM, even without methionine supplementation, in relation to liveweight (p<0.01), to food conversion and to the efficiency of utilization of metabolizable energy and to protein (p<0.05). At the 66% level of methionine supplementation, the same results as for these parameters were obtained at all of the levels of substitution of SM by PPM. The 30% or 45% substitution of SM protein by that of PPM affected (p<0.01) the efficiency of methionine utilization. The sulphur amino acid utilization efficiency was affected (p<0.01) beginning at 66% methionine supplementation in the diets.

Comportamento de cultivares de soja quanto a qualidade fisiológica de sementes

This work was carried out in order to evaluate if there was a relationship between genotypes and the physiological soybean (Glycine max L.) seed quality. It was conducted during three years using seven cultivars each year. The seeds were harvested at: 1) yellow radicle or expanded pod stage, 2) yellow pod or physiological maturity (R7), 3) harvest maturity (R8), and 4) R8 + 21 days delay. Seed moisture content, standard germination, and vigor tests were performed. The germination and vigor evaluated by accelerated aging and electrical conductivity did not show physiological seed quality differences among genotypes as harvested at physiological maturity. Then, the evaluation of seed germination and vigor, when the environment is not a considered factor, is not an efficient method to show differences among soybean genotypes in terms of seed quality.

Ganho genético por diferentes critérios de seleção em populações segregantes de soja

In breeding programs, the complexity of economically outstanding characters, most of which highly influenced by the environment, makes selection difficult. Using genetic parameters, like heritability and gain with selection, it is possible to identify superior genotypes in early generations. Therefore, the aim of the present research was to compare different selection criteria by the estimated gains and the selected progenies, determining the superior and more similar methods. Augmented block design was used with three additional checks. Twelve hundred genotypes were evaluated. The most expressive expected gains were obtained with direct selection. However, the indices have shown to be more appropriate for selecting superior progenies because of their higher total gains, distributed among all the evaluated characters. The Sum of Ranks Index allowed the highest gains in most of the situations analysed.

Caracterização de requeijão cremoso potencialmente prebiótico pela adição de inulina e proteína de soja

Requeijão is a typical Brazilian cheese and exhibits a significant consumption in the domestic market and presents high potential for functional foods. In this study the physicochemical characterization of requeijão cheese added of dairy cream, hydrogenated vegetal fat, soy protein isolate and inulin was carried out. For the requeijão cheese making it was used: Lactic mass, sodium chloride, melting salt, starch, whey protein concentrate, xanthan gum, nisin and water. Dairy cream (2.0; 4.0 and 6.0%), hydrogenated vegetable fat (6.0; 8.0 and 10.0%), soy protein isolate - SPI (0.5; 1.0 and 1.5%) and inulin (3.8; 5.05 and 6.3%) were added, according to the trial. The formulated products presented 6.26 to 6.38 of pH value, 0.24 to 0.39% of acidity, 7.29 to 10.04% of protein, 1.62 to 1.77% of ashes, 12.5 to 21.3% of fat, 39.8 to 66.1% of fat dry matter and 28.63 to 35.56% of total solids. The developed requeijão cheeses added of soy protein isolate and inulin are feasible alternatives for healthy foods and potentially prebiotics.