This study aimed to assess the potential of twelve cover crops in improving the structural state of the soil evaluating soil bulk density and soil resistance to penetration and their effects on crambe grain yield and oil content. The experiment was conducted at the Experimental Center of Agricultural Engineering (NEEA), at the State University of West Paraná (UNIOESTE)-Cascavel-Paraná. The cover crops were named as treatments and consisted of twelve species, namely: Crotalaria juncea, Crotalaria spectabilis, Pigeon pea, Jack bean, Foxtail millet, Forage sorghum, Lablab beans, Guandu beans, Mucuna aterrimum, Mucuna Pruriens, Mucuna deeringiana, Mucuna aterrima, and a control treatment (fallow area). The experimental design used consisted of randomized blocks with four replications and plots measuring 5 x 5 m. When species were in full bloom in May 2010, they were managed by desiccation with non-selective herbicide and subsequent mowing in order to accelerate the decomposition rate of their roots. In August 2011 we performed the planting of crambe for further analysis of its grain and oil yield. In January 2012 soil samples were collected to evaluate soil bulk density by the volumetric ring method at depths of 0.0-0.1, 0.1-0.2 and 0.2-0.3 m. Soil resistance to penetration was determined using a penetrometer until 0.4 m deep. In order to determine crambe grain yield, crambe was collected in an area of 4 m 2 in the central part of each plot. In ordet tor determe seed oil content it was used the Soxhlet method. The statistical analyzes for soil variables (soil penetration density and resistance) and plant (grain yield and oil yield) consisted of analysis of variance (ANOVA), with a comparison test of mean values. It was also performed linear regression analyzes between data concerning to grain yield and oil yield, as well as grain yield and bulk density. The species Crotalaria spectabilis and Mucuna aterrima provided a significant reduction in soil bulk density when compared to the fallow area, showing higher structuring potential than other species after the first year of use. Considering the structural state of the soil prior to the experiment, with bulk density values lower than 1.2 Mg m-3 , there was no significant effect on soil structure by any of the coverage species used and there was also no beneficial effect on crambe grain yield and oil content.

The selection of species that accumulate oil with potential for biofuel production has favored advancements in the scientific and technological domains within the Brazilian biofuel program. The equipments and methods used for such selection have always prosecuted the objective of increasing oil extraction. The aim of this paper was to evaluate the yield of oil extracted from five vegetable species -castor oil plant (Ricinus communis), physic nut (Jatropha curcas), soybean (Glycine max), groundnut (Arachis hypogaea L.), and crambe (Crambe abyssinica) with two different moisture contents and using two different solvents, hexane and ethanol. The experimental design was factorial (5 × 2 × 2), in which grains of each of the five vegetable species in two different moisture contents were used for oil extraction. It can be concluded from this study that grain moisture content and solvent type had great influence in determining oil yield; and that hexane extraction was most efficient. J. curcas had the greatest increase of oil yield with 30.70% when performing extraction with grain moisture. The smallest differences between the solvents were found in the species R. communis with 12% of higher efficiency with hexane extraction.

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O presente trabalho tem como objetivo descrever a caracterização morfométrica da bacia hidrográfica do Rio Ipiranga localizada no município de Santa Terezinha do Itaipu no Estado do Paraná e realizar o zoneamento climático para a região de estudo, para definir a viabilidade para o cultivo da soja com relação as condições térmicas e hídricas exigidas pela cultura buscando a maximização da produtividade regional para atender a crescente demanda por produtos alimentícios. Santa Terezinha de Itaipu fica a 619 km da Capital do Estado, Curitiba, via BR 277. Situa-se na região Oeste do Paraná possuindo um território com 259 km², o método utilizado para realizar o estudo do balanço hídrico da região foi o método de Thornthwaite & Mather. Considerando as exigências térmicas e hídrica da soja fica evidente que, para garantir máximo rendimento de grãos, o volume de água necessário deve ser disponibilizado ao longo de todo o ciclo, a fim de atender as exigências da cultura, podendo ser suprido através da chuva, da irrigação e/ou do armazenamento de água pelo solo. Este trabalho conclui que o município estudado revela-se apto para o cultivo de soja precoce e/ou tardia em relação às necessidades térmicas e hídricas, pois, todos os parâmetros são atendidos de acordo com o balanço hídrico da região de estudo.