965 resultados para Nitrifiable Nitrogen
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Nitrogen application on the cover and the maintenance of straw, conducted by direct seeding, should meet the needs of agriculture and promote soil conservation. This study evaluates the effect of pre-sowing nitrogen application in cotton crops and cover crops by direct seeding, on the development and yield of cotton. It was conducted in the municipality of Selviria-MS during the agricultural years 2005/06, 2006/07 and 2007/08. The experimental design used was a randomized block design consisting of three cover crops (forage turnip, black oat and white oat) and four nitrogen doses (0, 30, 60 and 90 kg of N ha(-1)) in pre-sowing of cotton. In April 2006, April 2007 and April 2008, the assessments of plant development and also harvesting of the experimental plots of cotton cultivars were conducted. The results showed that after planting the cover crops, the yield and development and the heights of cotton plants increased with the use of pre-sowing N of 90 kg ha(-1), also showing that the forage turnip is a coverage plant that provides increased cotton.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Consistent information on meat products consumed by the public is essential. The technique of stable isotopes is a powerful tool to recover consumers' confidence, as it allows the detection of animal byproduct residues in poultry meat, particularly in quail meat. This study aimed at checking the presence of poultry byproduct mixtures in quail diets by applying the technique of carbon (13C/12C) and nitrogen (15N/14N) stable isotopes in quail breast muscle, keel, and tibia. Sixty four one-day-old male quails were obtained from a commercial farm. Birds were housed in an experimental house from one to 42 days of age, and were randomly distributed into 8 experimental treatments, and fed diets containing poultry offal meal (POM), bovine meat and bone meal (MBM) or poultry feather meal (PFM), or their mixtures. Four birds per treatment were slaughtered at 42 days of age, and breast (Pectoralis major), keel, and tibia were collected for analyses. The inclusion of animal byproducts in quail diets was detected by 13C e 15N analyses in the tissues of the birds; however, it was not possible to specify which byproducts were used. It was concluded that quail meat can be certified by the technique of stable isotopes.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study proposed the use of the stable isotope technique to track the type of food utilized by pacu Piaractus mesopotamicus larvae during their development, and to identify the moment when the larvae start using nutrients from the dry diet by retaining its carbon and nitrogen atoms in their body tissues. Five-day-old pacu larvae at the onset of exogenous feeding were fed Artemia nauplii or formulated diet exclusively; nauplii+formulated diet during the entire period; or were weaned from nauplii to a dry diet after 3, 6 or 12 days after the first feeding. delta(13)C and delta(15)N values for Artemia nauplii were -15.1 parts per thousand and 4.7 parts per thousand, respectively, and -25.0 parts per thousand and 7.4 parts per thousand for the dry diet. The initial isotopic composition of the larval tissue was -20.2 parts per thousand and 9.5 parts per thousand for delta(13)C and delta(15)N respectively. Later, at the end of a 42-day feeding period, larvae fed Artemia nauplii alone reached values of -12.7 parts per thousand and 7.0 parts per thousand for delta(13)C and delta(15)N respectively. Larvae that received the formulated diet alone showed values of -22.7 parts per thousand for delta(13)C and 9.6 parts per thousand for delta(15)N. The stable isotope technique was precise, and the time at which the larvae utilized Artemia nauplii, and later dry diet as a food source could be clearly defined.
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The objective of the present study was to trace the inclusion of poultry offal meal (POM) in the diet of meat-type quails reared for a long period using the technique of stable isotopes. A number of 320 quails were randomly distributed into eight treatments: vegetable diet (T1), and a diet containing 8% POM were fed until the end of the experimental period (T2) or replaced by the vegetable diet on day 42 (T3), 56 (T4), 70 (T5), 84 (T6), 98 (T7), and 112 (T8). Breast muscle samples were collected from four birds randomly selected per treatment every 14 days. The obtained isotope results were submitted to multivariate analysis of variance (MANOVA) with the aid of the GLM procedure of statistical SAS program. Treatments were different from T1 when birds were sacrificed at least two weeks after the diet was changed. T2 results were different from T1 in all evaluated periods. It was concluded that it is possible to trace poultry offal meal inclusion in a strictly vegetable diet after the diet was changed for at least 14 days.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This work studied the influence of nitrogen source and sucrose concentration in the feeding medium for biomass and inulinase production by Kluyveromyces marxianus var. bulgaricus. The results show that the best nitrogen source was a combination of 5 g/L of yeast extract and 10 g/L of peptone. Both cellular growth and enzymatic activity increased with sucrose concentration in the feeding medium (from 200 to 500 g/L). When the sucrose concentration reached 600 g/L, both cellular growth and enzymatic activity decreased.
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Response to mineral fertilization and inoculation with rhizobia and/or arbuscular mycorrhiza fungi (AMF) of the Anadenanthera colubrina, Mimosa bimucronata and Parapiptadenia rigida (Leguminosae-Mimosoideae) native trees from Brazilian riparian forests, were studied in nursery conditions. Each species was submitted to seven treatments, varying nitrogen and phosphorous fertilization and inoculation with rhizobia (r), mycorrhiza (m) or both (rm): NP, P, P + r, P + rm, N, N + m and N + rm. Results showed that AMF inoculations did not enhance the mycorrhizal colonization, and P uptake was not sufficient to sustain good growth of plants. The level of P mineral added affected negatively the AMF colonization in A. colubrina and M. bimucronata, but not in P. rigida. Native fungi infected the three legume hosts. The absence of mineral N limited growth of A. colubrina and P. rigida, but in M. bimucronata the lack of N was corrected by biological nitrogen fixation. N mineral added inhibited the nodulation, although spontaneous nodulation had occurred in A. colubrina and M. bimucronata. Rhizobia inoculation enhanced the number of nodules, nitrogenase activity and leghemoglobin content of these two species. Thus, the extent of rhizobial and mycorrhizal symbiosis in these species under nursery conditions can affect growth and consequently the post-planting success. (C) 2004 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)