Desenvolvimento de metodologias eletroanalíticas para determinação de potássio e fósforo em biodiesel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspergillus niger e Glomus clarum incrementam a disponibilidade de fósforo em Latossolos sob Urochloa brizantha

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Doses de fósforo e zinco na cultura do feijão-caupi

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Fontes de fósforo e torta de filtro sobre o estado nutricional e produtividade da cana-planta

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

Parâmetros ósseos de frangos de corte alimentados com rações contendo fitase e baixos níveis de fósforo disponível e proteína bruta

504 (five hundred four) 1 day old male chicks from a commercial broiler line (Ag Ross 308) were used, distributed in 12 treatments, with 6 replicates per treatment. The experimental design was casually blocked and treatments were organized in a 2x2x3 factorial arrangement: two available phosphorus levels (0.45 and 0.34%), two phytase inclusion levels (0 and 1200 FTU/kg) and three crude protein levels (22.5; 20.5 and 18.5%). Tibia calcium percentage was influenced by protein and phosphorus levels in the diet, when using phytase. Tibia ash levels showed a linear effect when enzymes were added and showed a quadractic effect without it, and the higher value was observed with 22.5% crude protein in the diet. With higher phosphorus levels a linear effect was observed between crude protein in the diet and tibia ash weights, as a higher protein level had lower tíbia ash weight.

Influência da adubação com nitrogênio e fósforo na produção de Jambu, Acmella oleracea (L) R.K. Jansen

The objective of this work was to evaluate the influence of the use of nitrogen and phosphorus in the culture of jambu. The experiment was initiated at the experimental farm of the agency APTA Polo Vale do Ribeira, using the Nazaré cultivar. The experimental design was complete randomized with fourlevelsof nitrogen (0, 37.5, 75 and 112.5 kg ha-1 N) and phosphorus (0, 75, 150 and 300 Kg ha-1P2O5),and four reapplications. After soil preparation, liming and fertilization, seedlings of jambu were transplanted at a spacing of 0.50 x 0.5 m. The experimental plot was 1.0 x 1.0 m. Fresh and dry mass of leaves and flowers and number of flowers were analyzed. The production of fresh and dry leaves and flowers were influenced by fertilization. Thelevelsof nitrogen affected the outcome, as theyprovided a linear increase in all variables, and the phosphorus level of 75 kgha-1 P2O5 caused the highest average production in the number of flowers and in the fresh and dried mass of flowers.

Adubação com fósforo e potássio para produção e qualidade de sementes de soja

O objetivo deste trabalho foi avaliar os efeitos da adubação com fósforo e potássio na produção e na qualidade de sementes de soja. Foram realizados experimentos em dois anos agrícolas, em delineamento de blocos ao acaso, em arranjo fatorial 5x3, com cinco doses de fósforo (0, 40, 80, 120 e 160 kg ha‑1 de P2O5 como superfosfato triplo), três de potássio (0, 50 e 100 kg ha‑1 de K2O como cloreto de potássio) e quatro repetições. Foram avaliados: produtividade, número de sementes por planta, número de vagens por planta, peso de mil sementes, germinação, vigor (envelhecimento acelerado, condutividade elétrica e lixiviação de potássio), e teores de P e K na folha e na semente. A produtividade, o peso de mil sementes e a produção de vagens e de grãos por planta aumentaram linearmente com a adubação fosfatada. O aumento na produtividade foi de 17,6%, no primeiro ano, e de 39,7% no segundo. As doses de P, no entanto, não interferiram na germinação e no vigor das sementes. A adubação potássica não altera a produtividade nem a concentração de K nas sementes, mas pode melhorar a germinação, sem interferir no vigor.

Modelagem geoestatística das incertezas da distribuição espacial do fósforo disponível no solo, em área de cana-de-açúcar

Phosphorus is one of the limiting nutrients for sugarcane development in Brazilian soils. The spatial variability of this nutrient is great, defined by the properties that control its adsorption and desorption reactions. Spatial estimates to characterize this variability are based on geostatistical interpolation. However, inherent uncertainties in the procedure of these estimates are related to the variability structure of the property under study and the sample configuration of the area. Thus, the assessment of the uncertainty of estimates associated with the spatial distribution of available P (Plabile) is decisive to optimize the use of phosphate fertilizers. The purpose of this study was to evaluate the performance of sequential Gaussian simulation (sGs) and ordinary kriging (OK) in the modeling of uncertainty in available P estimates. A sampling grid with 626 points was established in a 200-ha experimental sugarcane field in Tabapuã, São Paulo State. The sGs algorithm generated 200 realizations. The sGs realizations reproduced the statistics and the distribution of the sample data. The G statistic (0.81) indicated good agreement between the values of simulated and observed fractions. The sGs realizations preserved the spatial variability of Plabile without the smoothing effect of the OK map. The accuracy in the reproduction of the variogram of the sample data obtained by the sGs realizations was on average 240 times higher than that obtained by OK. The uncertainty map, obtained by OK, showed less variation in the study area than that obtained by sGs. Thus, the evaluation of uncertainties by sGs was more informative and can be used to define and delimit specific management areas more precisely.

Comportamento dos óxidos de ferro da fração argila e do fósforo adsorvido, em diferentes sistemas de colheita de cana-de-açúcar

In agriculture, the search for higher crop yields based on sustainable soil management has led to a gradual pursuit of knowledge of the variables related to production systems. The identification of the causes of variability of these properties has become a part of strategic planning in the sugar and ethanol industry. This study investigated the spatial variability of iron oxides in the clay fraction and its relationship to soil physical and chemical properties in different sugarcane cultivation systems in the region of Ribeirão Preto, São Paulo State. Two 1-ha plots were outlined in areas with mechanical and manual harvesting systems. Soil samples were taken at 126 points from the 0.00-0.25 m layer in both areas. The mineralogical and chemical data were subjected to geostatistical analyses, to determine the spatial dependence, semivariograms and kriging maps of the properties. To analyze the correlation between the parameters cross-semivariograms were constructed. The spatial variability of chemical properties was greater in areas with mechanical harvesting than burnt harvesting (manual harvesting), whereas the range of the mineralogical properties was largest in the area of green-harvested sugarcane. The properties organic matter, mean crystal diameter goethite had a negatively spatial correlation, while clay was positive correlated with P sorption in the two sugarcane harvest systems.

Fracionamento do fósforo orgânico em solo adubado com esterco bovino

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

Disponibilidade de fósforo em solo cultivado com braquiária em rotação com soja

Pós-graduação em Agronomia (Agricultura) - FCA

Produtividade, qualidade fisiológica e composição química de sementes de crambe em diferentes doses de fósforo

The crambe is a brassica with high content of oil used for biodiesel production and that has aroused interest in the short cycle and low production cost. However, there are doubts about their response to phosphated fertilization. The objective of this study was to evaluate the effect of different doses of phosphorus on yield, physiological quality, chemical composition and oil content of crambe seeds. The treatments consisted of five doses of phosphorus (0, 25, 50, 75 and 100 kg ha(-1)) applied at sowing. There was no effect of phosphorus on mineral composition and oil content of the seeds of crambe that showed the following averages: 30.11 N, 7.46 P, 7.35 K, Ca 10.06, 6.58 mg and 8.98 g kg(-1) S; 36.25 Cu, Fe 169.40, 36.75 Mn 73.60 mg kg(-1) Zn and 30.22% oil. It was concluded that the productivity of crambe increases with phosphorus rates of up to 100 kg ha(-1), but its use does not affect the survival rate of plants, dry mass, the mass of thousand seeds, the physiological quality, chemical composition and oil content of the seed.

Adubação corretiva de fósforo sobre o desempenho de variedades de cana-de-açúcar cultivadas em ambiente restritivo de cerrado

Pós-graduação em Agronomia - FEIS

Fósforo na alimentação de pacus criados em tanques-rede

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

Resposta da cultura do milho a modos de aplicação e doses de fósforo, em adubação de manutenção

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