944 resultados para forrageiras, solos ácidos
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Resumo:
Pós-graduação em Ciência e Tecnologia Animal - FEIS
Resumo:
Pós-graduação em Microbiologia Agropecuária - FCAV
Resumo:
Pós-graduação em Genética e Melhoramento Animal - FCAV
Resumo:
Pós-graduação em Química - IQ
Resumo:
Soil that has a high degree of weathering, with more inorganic P bound to Fe and Al oxides, has less P availability to plants. Thus, the critical element of a plant refers to the level below which the growth rate and plant production decreases, demonstrating the need for supplementary fertilization. Accordingly, an experiment was conducted in a greenhouse at Embrapa Algodao with the objective of evaluating the response of castor plants to five doses of P in four types of soil with different adsorption characteristics and critical levels of foliar P. The experimental design was completely randomized in a 4 x 5 factorial design, four types of soil and 5 levels of P with four replications. For TCo, there was an increase in height growth, with dose of 229.6 mg dm(-3) responsible for maximum plant height (74.3 cm). The largest diameter stem (17.58 mm) was observed in CXve with an application of 229.6 mg dm(-3) of P; a decrease was seen when using higher doses. The increase in leaf area was smaller in RY (4724.8 cm(2)), where it was obtained with a dose of 280.2 mg dm(-3). In general, critical levels of P in the plant shoots did not vary much between the soils. The critical level of P in castor bean shoot dry mass was higher (4.61 g kg(-1)) in TCo, this result being directly related to the low clay content of the soil.
Resumo:
The objective was to evaluate fatty acids composition of the back fat in loin meat (Longissimus muscle) from Nellore and Canchim young bulls. The animals were finished at feedlot and received sugar cane diets with two concentrate levels (40 and 60% of dry matter). The concentrates were formulated with sunflower grains, corn, soybean meal, dry sugar cane yeast, urea and mineral mixture. The experimental design was a completely randomized design with a 2x2 factorial arrangement (genetic group x concentrate level), and the results were submitted to the variance analysis and means compared by Tukey test at 5% probability, when the interaction was significant. The loin backfat of Nellore bulls had higher concentration of conjugated linoleic acids than Canchim bulls (0.86 and 0.59%, respectively). On the other hand, the loin back fat of Canchim bulls had higher concentrations of estearic (17.07%) and linoleic acids (2.40%) and polyunsaturated fatty acids than Nellore bulls, that showed values of 13.47 and 1.44%, respectively. The Nellore and Canchim loin back fat presents significant amounts of beneficial fatty acids to human health. Levels of 40 and 60% of concentrate in the diet did not alter the fatty acids composition of loin backfat.
Resumo:
The mobility of water in the soil is a difficult process to be quantified. During precipitation, there is a portion of the water that infiltrates, which is very important for recovering the groundwater balance. This work studies the mobility of water in sandy soils with different textures and residual soils through experiments mounted in lysimeters. The lysimeters were mounted on acrylic cylinder with 11.3 cm diameter and 25.0 cm in length. The sand was deposited using the process sand rain. In the tests it was maintained a hydraulic head of two centimeters above the surface with the aid of a Mariotte flask. The portions of water were controlled in the experiments using relations between weight and volume measurements over time. The data were obtained by monitoring the input and output volumes of water through calibrated reservoir and system weight by an electronic balance. The infiltration front was monitored with the aid of a digital camera. The results indicate that the smaller the particle size of the sand, the lower the speed of the saturation front, the higher the retained volume, the smaller the basic rate of infiltration and the lowest speed of percolation. Moreover, the rate of water loss in the evaporation process indicated no significant difference with variation of the particle size of the samples
Resumo:
Previous studies show that in areas contaminated by fuel spill (NAPL- non-aqueous phase liquids), from operational activities, transport and storage, it was possible to observe a significant decrease of ²²²Rn (radon) gas concentration in the soil, even a non-uniform distribution of this gas in top soil, even with a geological situation was practically homogeneous. These anomalies may be associated with the preference partitioning of radon in NAPLs. This work consists of applying ²²²Rn as an indicator for locating subsurface contamination by NAPLs in an area of the city of Rio Claro (SP) where, according to the “Survey of Contaminated and Rehabilitated Areas in the State of São Paulo (Environmental Sanitation and Technology Company - CETESB), there was, in the year 2007, groundwater contamination from leaks of liquid fuels. The challenges of this research are: Promulgate the use of a new tool with greater efficiency in obtaining results, in addition to generate less impact in half and have less expenditure; disseminate scientific culture promoting greater integration of C&T (culture & technology) between universities and businesses. The emanometric technique to estimate the location, number and interfacial area of NAPL in saturated and non-saturated zone, has the advantage of locating and determining plumes of free phase even when the amount of VOC's (Volatile Organic Compounds) that reaches the surface is low or non-existent. In addition, the measurement techniques ²²²Rn are quite developed. The results obtained show that, similar to the other studies, the 222Rn soil gas presents an anomalous behavior in the area bounded by NAPL plume, being possible to note a significant deficit in the concentration of the gas in spots where the saturation by NAPLs is still critical. Therefore it is concluded that this tool is really promising, but we must be careful to evaluate the initial conditions of the area, as well as the type of...
Resumo:
É comum congêneres do cerrado brasileiro mostrarem-se morfologicamente semelhantes, mas com padrão de ocorrência distinto. O sucesso de uma espécie em um hábitat é fortemente dependente de seu desempenho ecofisiológico, que pode relacionar-se aos recursos naturais de seu ambiente. Hipotetiza-se fundamentalmente que os referidos congêneres apresentam diferentes taxas de crescimento radicular, e o solo também pode representar fator determinante para a ocorrência de espécies de cerrado. Diante disso, também é admitida a hipótese de que esses congêneres apresentam maior crescimento se cultivados em solo de cerrado ou solos relacionados às áreas dos fragmentos de cerrado em que ocorrem, do que quando cultivados em solos mais férteis. Ainda, baseando-se em observações de campo, supõe se que dentre os congêneres, S. ferrugineus deve ter o maior crescimento de raízes e o menor crescimento da parte aérea. Também é provável que S. camporum mostre a maior plasticidade de crescimento em resposta à fertilidade do solo, dada sua ampla ocorrência em relação a diferentes hábitats. Para testar essas hipóteses, objetiva-se medir o crescimento da raiz principal em solo de cerrado s.s., através de observações em rizotron. Também serão medidas as taxas de crescimento da raiz principal, a altura da planta, número de folhas e ganho total de biomassa dos três congêneres em resposta a dois solos com características e fertilidades contrastantes. Um dos solos será originário de um fragmento de cerrado s.s. e o outro, um substrato utilizado para viveiros de plantas nativas florestais da região. Será um experimento com nove repetições (rizotrons). O crescimento da raiz principal será medido em intervalos de 10 dias, até 180 dias de cultivo. A biomassa total final será medida através de coleta destrutiva. Os fatores estudados serão as três espécies... (Resumo completo, clicar acesso eletrônico abaixo)