Wood Ash in Canavalia ensiformis L. Cultivation on Highly Weathered Soil in Brazil

The aim of study was to avaliate the productive and structural features of Canavalia ensiformis L. resulting from the wood ash acting as a soil corrective and fertilizer in the Oxisol. The experiment was performed in a greenhouse, from April to July 2012, in the Municipality of Rondonópolis, State of Mato Grosso, Brazil. The experiment, with Oxisol, use as of six wood ash doses (0.0, 3.0, 6.0, 9.0, 12.0 and 15.0 g dm-3). Harvesting of the Canavalia ensiformis L. was done 60 days post germination, in plastic pots of 4 dm-3 capacity, to which the wood ash doses had been administered 20 days prior to planting. At the time of flowering, the following measurements were recorded, plant height, indirect chlorophyll index of leaf, stem diameter, leaf number count, soil pH, dry mass of shoot, dry mass of root, numbers and dry mass of the Rhizobia-rich root nodules. The findings were then submitted to the analysis of variance and regression test, up to p=0.05 significance. The wood ash acted as a corrective and induced a pH increase, enhancing the soil chemistry. Influencing the number of leaves, dry mass of leaves and nodules. The other variables analyzed, which were adjusted to the quadratic regression model, demonstrated improved results when 9 to 12 g dm-3 of wood ash per pot were added.