Performance of Piata and Paiaguas Grasses Fertilized with Wood Ash in Entisol Soil

摘要

The aim of this study was to assess the yield of the Piat? and Paiaguás cultivars of the Urochloa brizantha grass, grown in the in Entisol utilizing wood ash as the fertilizer. Performed under greenhouse conditions, the randomized complete block design was adopted for the experiment in a 2x5 factorial scheme, using two Urochloa brizantha cultivars (Piat? and Paiaguás) in five treatments (0, 8, 16, 24 and 32 g dm-3) with five replications. The experimental units included plastic pots, 5 dm3 in capacity, filled with Entisol. The soil was enriched with wood ash 30 days prior to planting. Each experimental unit supported the cultivation of five plants. Three evaluations of the plants were done in 30-day intervals, in which the leaf dry weight, shoot dry weight and shoot mass were evaluated. After submitting the data to the analysis of variance, further analysis was done by the Tukey test for the qualitative data (cultivars) and polynomial regression for the quantitative data (doses of wood ash), with up to 5% probability. Comparing the two cultivars, the shoot dry mass production was higher in the Piat? cultivar, in all evaluated cut. As a function of the plant ash doses, the shoot dry mass data were adjusted to the quadratic regression model, with a maximum yield of 26.6 g pot-1 at the dose of 24.47 g dm-3 in the third cut. For leaf dry mass, the highest yield was obtained in the dose of 21.8 g dm-3 in the first cut, reaching 15.3 g dry mass of leaves per pot. In the third cut, the maximum yield of stalk dry mass was observed at the dose of 24.9 g dm-3. This experiment showed that plant ash influenced the dry mass production of the shoots, as well as leaves and shoots of the Piat? and Paiaguás grasses positively, inducing a maximum yield of between 20 and 30 g dm-3 of wood ash.