Bulk Density in Jack Bean’s Development Grown in Cerrado Oxisol

Abstract

The use of cover plants promotes the recycling of nutrients and the increase in organic mass, and minimizes the effects of erosion. The objective was to evaluate the effect of bulk density in the development of jack bean ( Canavalia ensiformis ) in Cerrado Oxisol. The experiment was conducted in a greenhouse at the Federal University of Mato Grosso, Rondonópolis-MT, in the period from June to September 2013. Oxisol was used from a Cerrado reserve area, collected at 0 - 0.20 m depth. The experimental design was completely randomized, corresponding to bulk density levels (1.0, 1.2, 1.4, 1.6 and 1.8 Mg &middot m ^-3 ), and five replications. The experimental plot consisted of three PVC rings (polyvinyl chloride) with 150 mm internal diameter, 300 mm total height, where the upper and lower rings of pots were filled with 1.0 Mg &middot m ^-3 density soil and intermediaries according to bulk density treatments. The results were submitted to variance analysis and, when significant, to regression analysis, both with a 5% probability, using SISVAR software. At 60 days after germination, number of leaves, stem diameter, plant height, dry mass of leaves, stem dry mass, dry mass of roots, dry mass of nodules, number of nodules and chlorophyll index (SPAD index) were evaluated. The increase in bulk density negatively influences the development of jack bean, showing little efficiency as a decompacting plant in Cerrado Oxisol.