Abstract

Similar to many other human activities, the energy sector has a global concern with environmental issues. The use of renewable energy sources such as biomass is an alternative to the use of fossil fuels. Eight elephant grass genotypes showing energy production potential were herein assessed. The genotypes were grown from February 2014 to March 2016 in Campos dos Goytacazes County – Rio de Janeiro State, Brazil. They were fertilized with three different nitrogen doses (400, 1000 and 1600 kg N ha-1) and two potassium doses (200 and 500 kg K2O ha-1). The experiment followed a randomized block design, with three repetitions, using a split-plot factorial scheme. The aim of the current study was to assess the effect of different nitrogen and potassium doses in fertilizing different genotypes of elephant grass by analyzing the morphoagronomic traits. The lowest K dose (200 kg ha-1) was enough to generate the best outcomes in characteristics presenting significant effects. The N increase in the fertilization process did not promote dry matter production gains. The lowest N dose (400 kg ha-1) was enough to promote the highest values. As for the other traits assessed in the current study, although there was a genotype that showed statistically significant difference from any other genotype at a particular dose, the increasing N doses in the fertilization did not influence the performance of the genotypes.

Key words: Renewable energy, biomass, mineral nutrients, Pennisetum purpureum Schum.