Características morfogênicas de gramíneas nativas do sul do Brasil sob níveis de nitrogênio

Abstract

The morphogenetic characteristics of eight native grasses of South Brazil were evaluated during autumn. They were classified in a functional typology, according to dry matter content and specific leaf area (A, B, C, D): Axonopus affinis (A), Andropogon lateralis (B), Paspalum notatum (B), Paspalum plicatulum (C), Piptochaetium montevidense (C) Aristida laevis (D), Saccharum angustifolius (D) and Sorghastrum pellitum (D), under two nitrogen (N) fertilization levels (zero and 200kg ha-1 N). Experimental design was completely randomized in a factorial arrangement: eight (species) x two (N levels) with three replicates or four (functional types) x two (N levels) both with three replicates. Plants were submitted to cuts according to different leaf lamina elongation, defined by means of species classified by functional type. The variables were statistically analyzed using randomization tests with software MULTIV. There was no significant difference between N levels, but there was among species and among functional types. Morphogenic variables are consistent according to the functional typology used as reference, based on leaf traits. Nitrogen fertilization does not change morphogenetic characteristics of evaluated species during autumn, and its use is discouraged during this season.