438 research outputs found

    Herbicides Effect on Nitrogen Cycling in Agroecossystems

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    O farelinho de trigo fermentado com Bacta-Mon e excremento de vaca na alimentação de pintos

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    Bacta-mon, produced by Bacta-mon S. A., São Paulo, Brazil, is recommended as a microbiological, and suggested as a supplement for animal rations. This experiment deals with this product in chicken feeding. Four lots of baby chicken received, during 6 weeks the following treatments: a control ration Rl; a ration R2 containing 10 per cent of wheat standard middlings fermented by Bacta-mon, substituting equal weight of wheat standard middlings of the control ration Rl; two rations R3 and R4, both without meat meal and containing 10 per cent of wheat standard middlings fermented respectively by Bactamon and fresh cow manure, substituting equal weight of wheat standard middlings of the control. The results may be so summarized: (1) On the basis of the weights of the chicks at 6 weeks age, we concluded that there was not any advantage in the addition of the wheat standard middlings fermented by Bacta-mon. (2) The rations R3 and R4 were considered statistically equivalents and lower the control ration Rl. (3) It seems that the main difference observed in these results may be atributed to lack of animal protein. (4) The highest mortality and the lowest consumption of feed by the lots receiving ration R3 and R4, seem to indicate, in addition, that this prejudice was due the lack of animal protein and the unpalatability of these rations

    Alimentação dos marrecos: III sôro de leite (Líquido)

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    The author studied in this paper the influence of liquid whey in feeding Pekin ducklings. Wet mash, either by liquid whey or water, was given to the ducklings during the whole day. Green feed was added to the ration just once a day. The statistical analysis did not show significant differences between the use of water and liquid whey but the results obtained with wet mash proved to be statistically better than the results obtained with dry mash

    Substituição do farelo de trigo pelo farelo de sabugo de milho

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    Two 50 R. I. R. chicken groups were contrasted, both receiving the same basic-ration differing only in the content of wheat bran or corn cobs meal. One ration had 10% of wheat bran and in the other one the 10% of wheat bran has been substituted by 10% of corn cobs meal. It was found on the final weight a significant advantage of 12,8% with wheat bran. However, the development of chikens receiving corn cobs meal was quite normal

    Avaliação de um modelo de parcela com fertilizante-15N na determinação do aproveitamento do nitrogênio do fertilizante por cana-de-açúcar

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    Two experiments were conducted on commercial sugar cane fields cropped with the variety SP70-1143, with the objective of evaluating a single row microplot design to determine plant recovery of 15N fertilizer nitrogen. One of them used 15N-aqua ammonia and 15N-urea applied to two linear meter microplots of a ratoon crop (four replicates). The second used one linear meter microplots (three replicates) which received 15N-aqua ammonia only. The fertilizers were applied on 15cm deep furrows, located 25cm from both sides of the cane row. One linear meter of ratoon cane, inside and outside of the microplot, and on the same and adjacent rows were harvested twelve months after fertilization. The results indicate the feasibility of using single row segments of ratoon cane with 15N-fertilizer. The main advantage of this microplot design, when compared to the classical 3 contiguous row segments, is that only one third of the labeled fertilizer is needed. In a single row, in order to separate the nitrogen taken up by plants from the fertilizer applied to the row (Nr dff r), from that applied to adjacent rows (Nr dff r+1, and Nr dff r-1), the following should be considered: (a) a border segment of 0.5 to 1.0m inside the plot, so that Ndff results from plants harvested in the center of the microplot represent the actual value of fertilizer nitrogen taken up from that applied to the same row, and (b) harvest of plants from adjacent rows at equivalent positions to those sampled inside the microplot, to quantify the 15N-fertilizer uptake by outside plants (Nr+1dff r and Nr-1dff r), which is assumed to be the same as non labeled fertilizer applied to adjacent rows (Nr dff r+l and Nr dff r-1) taken up by inside plants. The Ndff total values should be calculated by the equation: Ndff total = Nr dff r + Nr+1dff r + Nr-1dff r.Com o objetivo de avaliar um modelo de parcela, na determinação do aproveitamento pela cana-de-açúcar de fertilizantes nitrogenados-15N, foram conduzidos dois experimentos em áreas comerciais plantadas com a variedade SP 70-1143. Num experimento foram aplicados os adubos aquamônia-15N e uréia-15N, em parcelas constituídas de segmentos simples de linha de soqueira de cana, com 2 metros lineares de comprimento (4 repetições). No segundo, parcelas de l metro linear (3 repetições) receberam aquamônia-15N. Os fertilizantes foram aplicados em sulcos com 15cm de profundidade, abertos a 25cm de distância nos dois lados da linha de cana. Foram realizadas colheitas de l metro linear de cana no interior e fora das parcelas, na mesma linha e nas adjacentes à elas. Os resultados isotópicos evidenciaram ser perfeitamente possível a utilização dessas parcelas com fertilizante-15N. A principal vantagem do modelo, comparado às parcelas convencionais com 3 segmentos contíguos, é a redução a um terço, da quantidade de fertilizantes-15N necessária. Na determinação do nitrogênio absorvido pelas plantas do fertilizante aplicado na linha com adubo-15N (Nr dff r), e daquele absorvido do fertilizante não marcado com o isótopo, aplicado nas linhas adjacentes (Nr dff r+1 e Nr dff r-1), deve-se considerar para as parcelas em questão: (a) bordadura interna de 0,5 a 1m de comprimento, para que os valores de Ndff de plantas colhidas no centro delas, representem o valor máximo do nitrogênio absorvido do fertilizante aplicado na linha; e (b) colheita de plantas nas linhas imediatamente adjacentes, em posições equivalentes à efetuada no interior das parcelas, a fim de quantificar o N absorvido do fertilizante-15N (Nr+1dff r e Nr-1dff r), que representa o valor do N absorvido do adubo aplicado nas linhas adjacentes, por plantas da parcela (Nr dff r+I e Nr dff r.,). O valor de Ndff^ é calculado pela equação: Ndff total= Nr dff r + Nr+1dff r + Nr-1dff,

    Straw mineralization and root growth of sugar cane as related to nitrogen fertilization at planting

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    O experimento foi realizado em canavial comercial, com a variedade SP81 3250, na Usina São Martinho (Pradópolis-SP), em Latossolo Vermelho-Escuro de textura argilosa, com o objetivo de avaliar a mineralização da palha de cana-de-açúcar e sua composição após um ciclo de desenvolvimento da cultura. Foi utilizado um delineamento experimental de blocos completos casualizados, com quatro repetições. Sacos de telas que continham palha marcada em 15N (1,07 % de átomos de 15N), em quantidades equivalentes a 9 t ha-1 de matéria seca, foram colocados entre as fileiras de cana-planta, em todos os tratamentos (0, 40, 80 e 120 kg ha-1 de N). Após 14 meses (de junho 2005 a agosto 2006), foram retirados os sacos para a quantificação do material seco remanescente e para determinações de N, de isótopos de 15N e do teor de C, por espectrometria de massas. A decomposição da palhada nos sacos foi maior nos tratamentos adubados com N e o balanço de massa subestimou a liberação do N da palha em comparação com os dados obtidos com a técnica isotópica. Após 14 meses, verificou-se que 37 a 65 % da matéria seca do material da palhada remanescente sobre o solo eram compostos por restos de raízes da cana cultivada durante esse período, pela contaminação por solo e por microrganismos que se desenvolveram na palhada, indicando que os processos ocorridos durante a decomposição da palhada são mais dinâmicos do que os avaliados pelo balanço de massas.The experiment was conducted with the sugar cane variety SP81 3250, in a commercial area of the sugar mill São Martinho (Pradópolis-SP), on a clay-texture Rhodic eutrustox. The experimental had a randomized block design with four replications. Bags containing straw enriched with 15N (1.07 % 15N atoms) equivalent to 9 t ha-1 dry matter were placed on the soil surface between the sugar cane plant rows in all treatments (0, 40, 80 and 120 kg ha-1 of N). After 14 months (from June 2005 to August 2006) the bags were removed to quantify the remaining dry material, determine total N and C, and 15N isotopic concentration by mass spectrometry. Results indicated that straw decomposition was higher in the N fertilized treatments and that the mass balance underestimated the N amounts released from straw. The isotopic technique showed that after 14 months, between 37 and 65 % of the dry mass of the straw remaining on the soil surface came from the live sugar cane rooting system or from microorganisms and soil residues adhered to the straw. This suggests that the processes that occur during straw decomposition are more dynamic than those evaluated by mass-balance equations

    Plot-size for 15N-fertilizer recovery studies by tanzania-grass

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    O entendimento da dinâmica do N em ecossistemas de pastagens pode ser melhorado por estudos em que se utilize a técnica do traçador 15N. Nesses experimentos, deve-se assegurar que o movimento lateral do traçador não interfira nos resultados. Neste trabalho foram determinadas as exigências quanto ao tamanho da parcela para experimentos com 15N em pastagem irrigada de Panicum maximum cv. Tanzânia. Foram consideradas três intensidades de pastejo (leniente, moderada e intensa) em três épocas do ano: inverno, primavera e verão. Parcelas de 1 m², com uma touceira do capim ao centro, foram adequadas, independentemente da intensidade de desfolha ou da época do ano. O aumento na distância da área adubada com 15N influenciou negativamente a quantidade de N proveniente do fertilizante (Npfm) recuperado na forragem. As menores taxas de declínio nos valores de Npfm foram observadas para as intensidades de pastejo leniente e moderada; esse fato pode ser explicado pelas características de crescimento vigoroso dessas plantas. O aumento na intensidade de pastejo determinou a redução na massa da touceira: quanto menor a touceira, maior a sua dependência do N do fertilizante.The understanding of the N dynamics in pasture ecosystems can be improved by studies using the 15N tracer technique. However, in these experiments it must be ensured that the lateral movement of the labeled fertilizer does not interfere with the results. In this study the plot-size requirements for 15N-fertilizer recovery experiments with irrigated Panicum maximum cv.Tanzania was determined. Three grazing intensities (light, moderate and intensive grazing) in the winter, spring and summer seasons were considered. A 1 m² plot-size, with a grass tussock in the center, was adequate, irrespective of the grazing intensity or season of the year. Increasing the distance from the area fertilized with 15N negatively affected the N derived from fertilizer (Npfm) recovered in herbage.The lowest decline in Npfm values were observed for moderate and light grazing intensities. This fact might be explained by the vigorous growth characteristics of these plants. Increasing the grazing intensity decreased the tussock mass and, the smaller the tussock mass, the greater was the dependence on fertilizer nitrogen

    Crescilin (suplemento de penicilina G procaína cristalina) na alimentação de leitões

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    The A. studied the use of "crescilin", a residual byproduct of penicillin manufacture. It has been recommended the proportion of 1 per cent and proclaimed to supply 400,000 U. O. per kg. The results obtained permited to conclude that 1 per cent of crescilin did not increase the growth of pigs

    Resposta de pastagens de capim-marandu em solo de cerrado à adubação com nitrogênio, em condições de sequeiro. ou sob irrigação

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    Almeirão, quicúio e grama seda como alimento verde para pintos em crescimento

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    The author studied in this paper effect of chicory (Chicorium intybus L.), kikuyugrass (Pennisetum clandestinum Hoahst) and a variety of Bermuda grass (Cynodon dactilon Pers.) named "Grama seda" as green feeds in growth of White Leghorn chickens (0-8 weeks). Males and females were se-pareted by feathering and development of comb. The results obtained can be summarized as follows : a) - Without separation of sex, the chickens that received green feeds showed better development than that did not receive green suplements. b) - The chicory showed to be something better that kikuyugrass and Bermuda grass, which had a similar effect. c) - The green feeds used had little influence in development of males. d) - The females in the lots suplemented by green feeds showed to be superior to the females in the lots that did not receive it. e) - The author think that the presence of some priciples having action in the female hormony function is responsable for the better growth in the lot that received green feeds
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