Conteúdo de água, intensidade e profundidade de compactação sobre o crescimento inicial de Jatropha curcas L.

Abstract

The instability in oil prices and concerns about global climate change has intensified the study and use of renewable energy sources, foremost among these options, research and further exploration of potential sources of ethanol plants and biodiesel. For technical characteristics of Jatropha oil, mainly because 83.9% of the calorific value of diesel oil, that crop becomes an alternative for biodiesel production in Brazil. In order to evaluate the initial development of jatropha, submitted at two water contents in soils under different intensities and depth of compression is set up this experiment, which was conducted in a greenhouse at the Faculty of Agricultural Sciences / UFGD, in Dourados-MS, and the soil was a Oxisol, clayey. We used a randomized block design and treatments were arranged in plots sub-divided, and the two portions of water content (70% and 100% of field capacity), the subplots were two different depths in compression ( 5-10 and 10-15 cm) and the split were four levels of soil bulk density (1.0, 1.10, 1.20 and 1.40 Mg m-³), with four replications. There was an interaction of water levels and compaction depth on the fresh weight of shoots. There was a combined effect of water levels on the density and height, and depth of compaction density on emergence percentage, and the index of emergency speed. Water levels affected fresh shoot mass, and the final height of plants. The compression depth significantly affected plant height. There were isolated effect of density of soils on the index of emergency speed on the percentage of emergence, fresh shoot and plant height. For jatropha 70% of field capacity is sufficient for the initial development, and the depth of compaction influence the initial development of this crop. And for this type of soil bulk density to 1,25 Mg m-³, favors the growth of the plant jatropha, becoming harmful above this density.