Aplicação de escória siderúrgica calcário e ureia em latossolo cultivado com arroz

A escória de siderurgia é um silicato de cálcio e fonte de silício, que tem ação corretiva da acidez do solo semelhante à do calcário. Apesar do seu grande potencial de uso como corretivo e fertilizante, existem poucas informações sobre seus efeitos nos atributos químicos do solo. O estudo foi realizado com a cultura do arroz, objetivando-se avaliar os efeitos da aplicação da escória de siderurgia, calcário e ureia nas alterações dos atributos químicos de um Latossolo Vermelho distrófico. Os tratamentos constaram da combinação de duas fontes de materiais corretivos (calcário e escória de siderurgia), em três doses (1,3 g dm-3 2,6 g dm-3 e 5,2 g dm-3; três doses de N (80 mg dm-3 160 mg dm-3e 320 mg dm-3, aplicadas na forma de ureia; e uma testemunha, dispostas em blocos casualizados, em esquema fatorial, com quatro repetições. Após o período de 90 dias de incubação do solo e 120 dias de cultivo da cultura do arroz, coletaram-se amostras do solo, para análise química. A escória de siderurgia foi viável como corretivo de acidez do solo e a adubação nitrogenada em arroz contribuiu para incrementos na acidez do solo, diminuindo a saturação por bases e o teor de Ca e Mg. A aplicação de escória de siderurgia favoreceu a disponibilidade de silício, entretanto, quando associada à adubação nitrogenada, não alterou o teor deste elemento no solo.

Avaliacao da necessidade da dosagem rotineira de hematocrito, hemoglobina, ureia e creatinina sericos durante a avaliacao pre-anestesica

Background and Objectives - There are many questions and opinions about the value of routine preoperative tests as an integral part of the preanesthetic evaluation. Current trends suggest that such tests should be based on detailed clinical and physical evaluation. Since such tests are still routinely performed and questions about their real value still persist, the aim of this study was to assess the value of routine hematocrit (Ht), hemoglobin concentration (Hb), blood urea nitrogen (BUN) and serum creatinine results in patients undergoing elective surgery, to establish when they are needed and aiming at answering such questions. Methods - 1065 patients aged 12 years and above, physical status ASA I, II and III, scheduled for elective surgery were studied. Patients were divided into 7 different age groups with randomized distribution of gender. Ht, Hb, BUN and serum creatinine results, routinely asked by our surgical departments, were observed and analyzed. Variance Analysis was used for each variable, and the Bonferroni Multiple Comparison Test was used to compare group to group. Differences were considered significant when p < 0.05 (5%). Results - For all patients, 4025 laboratory tests were obtained. The number of tests was the same for each group. There were no differences in Ht and Hb values which remained within normal ranges. Considering BUN and serum creatinine, there was a difference between younger and older patients, but the results were normal in all groups. Conclusions - We concluded that mean Ht, Hb, BUN and serum creatinine values in all age groups were all acceptable for surgical patients in general. However, they are barely useful if performed regardless of clinical evaluation. Thus, such preoperative routine tests should be abandoned and the good clinical practice with common sense should prevail in indicating them.

Composição química e digestibilidade in vitro da massa seca de cana-de-açúcar acrescida de ureia em diferentes tempos de estocagem

The objective of this research was to evaluate the chemical composition and in vitro dry mass (DM) digestibility of sugar cane with urea, maintained in the shade and sun, at different storage times. The utilized design was the completely randomized in a factorial scheme 6x2, that is, six storage times after the mixing (0; 2; 4; 6; 12 and 24 hours) and two storage location (shade and sun), with three replicates. The sugarcane utilized presented 12 months of development and was disintegrated for application of mixture (nine parts of urea for one of ammonium sulfate) to 1.0kg/100.0kg of fresh sugarcane. The samples taken with 12 hours of storage indicated that was an increase in the content of DM and crude protein (CP) of sugar cane compared to the moment of the mixture (307.6 vs. 294.2g/kg of DM and 115.2 vs. 99.3 g/kg of DM, respectively), and the smaller content of neutral detergent fiber (NDF) was observed around of 12 hours of storage (465.0g/kg of DM). The coefficients of in vitro dry mass digestibility (IVDMD) ranged of 0.558 to 0.612 in the times 0 and 12 hours, respectively. The length of storage changes the chemical composition of sugar cane plus urea. The storage location changes the dry mass content and pH values.

Formas de ureia e doses de nitrogênio em cobertura na qualidade fisiológica de sementes de trigo

Besides increasing productivity, nitrogen fertilization may have positives effects on seed physiological quality. The objective of this study was to evaluate the effect of different forms and levels of urea in top dressing fertilization on the physiological quality of wheat seed genotypes. Seeds of three wheat genotypes (BRS 208, BRS Pardela and IWT 04008) were evaluated for four levels of nitrogen fertilization (0, 40, 80 and 120 kg.ha-1) in three forms of urea (conventional urea, urea with urease inhibitor and protected urea). The nitrogen fertilization was applied during tillering, 20 days after emergence. The seed nitrogen content, 1000 seed mass, germination and vigor (germination first count, cold test, seedling emergence in the field, dry weight of seedlings, accelerated aging and electrical conductivity) were evaluated. The IWT 04008 line and the cultivar BRS Pardela had seeds with a higher physiological quality than those of the cultivar BRS 208. The forms of urea and levels of nitrogen in topdressing did not affect seed physiological quality of the different wheat genotypes.

Fontes energéticas associadas ao farelo de girassol ou à ureia em dietas para novilhos

The objective of this study was to evaluate the performance and carcass traits of steers fed corn or citrus pulp associated with sunflower meal or urea. Diets were composed of two energy sources (corn grain and citrus pulp) associated with two protein sources (soybean meal and urea), resulting in four treatments in forage:concentrate ratio of 40:60. It were used 24 steers, 1/2 Angus × 1/2 Nellore (18 months old and 329 kg BW) distributed in a completely randomized design which were finished in feedlot for 80 days. It were evaluated the intake, average daily gain and carcass traits of the animals. Intake of dry matter (DMI), crude protein (CPI) and neutral detergent fiber (NDFI) were affected (p<0.05) by diets. The diet with citrus pulp and urea (PU) showed the lowest (p<0.05) DMI (8.30 kg), CPI (1.03 kg) and NDFI (3.31 kg). The average daily weight gain (ADG) followed the behavior of DMI, NDFI and CPI and the lowest value (p<0.05) was observed for animals fed diet PU. Regarding carcass traits, diets containing corn associated with urea (MU) or sunflower meal (MFG) and citrus pulp associated with sunflower meal (PFG), provided the highest (p<0.05) carcass cold weights (238.37, 247.26 and 237.14 kg, respectively). However, the lowest cold carcass dressing percentage (p<0.05) was obtained in diet MU (50.57%). The association of citrus pulp with urea should not be performed when citrus pulp partially or totally replace corn as energy source in diets, because possibly this association promote an energy deficit resulting in lower performance and worse carcass traits of animals finished in feedlot.

Produtividade e teor de nitrato de alface e rúcula em cultivo consorciado e monocultivo em função da adubação com N-ureia e esterco bovino

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Doses de N-ureia e de esterco bovino na qualidade nutricional da rúcula em consórcio com a alface

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Doses de N-Ureia e de esterco bovino na qualidade nutricional da alface em consórcio com a rúcula

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Consumo e digestibilidade de dietas contendo fontes energéticas associadas ao farelo de girassol ou ureia em novilhos confinados

Objetivou-se avaliar o consumo e a digestibilidade total e parcial de dietas utilizando milho, casca de soja e polpa cítrica associados ao farelo de girassol ou ureia em novilhos confinados. Foram utilizados quatro novilhos ½ Aberdeen Angus vs. ½ Nelore, providos de cânulas no rúmen e duodeno, com 18 meses de idade e 360 kg de peso médio inicial. As dietas foram constituídas por duas fontes energéticas (milho grão e polpa cítrica) associadas a duas fontes nitrogenadas (ureia e farelo de girassol), totalizando quatro tratamentos, numa proporção volumoso:concentrado de 40:60. O delineamento utilizado foi o quadrado latino com quatro tratamentos e quatro períodos de 21 dias cada. O consumo médio diário de matéria seca foi influenciado (p < 0,05) entre as dietas, e o maior valor foi atribuído à dieta milho e farelo de girassol. A digestibilidade aparente de todos os componentes, exceto da proteína bruta, foi maior (p < 0,05) para as dietas com polpa cítrica. Não houve efeito (p > 0,05) entre as dietas para as digestibilidades ruminal e intestinal. A utilização de coprodutos na alimentação animal não prejudicou a digestibilidade das dietas, sendo indicados como ingredientes de elevado potencial de utilização em dietas para bovinos de corte.

Análise isotópica (Delta15N) e química do capim-marandu adubado com ureia e cama de frango e diferido

Pós-graduação em Zootecnia - FMVZ

Glicerina associada à ureia na alimentação de bovinos Nelore

Pós-graduação em Zootecnia - FCAV

Composição química e digestibilidade in vitro da massa seca de cana-de-açúcar acrescida de ureia em diferentes tempos de estocagem

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

Condições, modos de aplicação e doses de ureia revestida por polímeros na cultura do milho

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

Adubação nitrogenada na cultura do milho com ureia revestida por diferentes fontes de polímeros

In view of theoretic increase in efficiency of nitrogen fertilizers for controlled release, this study aimed to evaluate the effect of nitrogen, using conventional urea and ureas coated by different polymers, in the leaf N content, leaf chlorophyll index, components production and grain yield of irrigated corn in growing season and second crop in the savannah region. The experiments were conducted at experimental area belonging to UNESP - Ilha Solteira, located in Selviria - MS in a dystrophic Red Latosol (Haplustox), clayey texture. The statistical design was randomized blocks, with four repetitions, in a 4 x 4 factorial arrangement, being four nitrogen doses (0, 40, 80 and 120 kg ha(-1)) applied at sidedressing and four urea sources (a conventional urea and three coated with polymers in different compositions and concentrations). The coated ureas are not efficient under the soil and climate conditions studied of the savanna, because they provided results similar to the conventional urea for the production components and grain yield of corn in the first and second crop. The increment of nitrogen doses increase linearly the leaf N content and grain yield of corn in the first and second crop.

Mineralização de nitrogênio do esterco bovino e produção de alface em função de N-ureia

Pós-graduação em Agronomia (Ciência do Solo) - FCAV