Produtividade e valor nutritivo do capim elefante inoculado com Azospirillum brasilense em diferentes sistemas de produção

Abstract

The objective of this research was to evaluate elephant grass in two production systems subjected to inoculation of plant growth promoting bacteria Azospirillum brasilense. In the organic system, summer and winter cycle species were combined, elephant grass was established in lines 3 m apart; among the rows of elephant grass, during the winter period, ryegrass was sown and in the summer period the development of spontaneous growth species was allowed. In conventional production, elephant grass was cultivated alone, representing how it is done in properties that use this forage grass. Were applied 120 kg of N ha-1 in both systems, with mineral (urea) in conventional production and organic fertilizer (cattle manure and poultry litter) in organic production, the fertilizers divided into four applications. Holstein cows were used in the evaluation. The experimental design was completely randomized in a 2x2 factorial arrangement (production systems x with and without A. brasilense inoculation), with 3 repetitions (paddocks) and with repeated measures over time (seasons). During the experimental period (366 days), seven grazing were carried out in the organic system and five grazing in the conventional system. Forage mass parameters at pre- and post-grazing, forage yield, grazing efficiency, apparent consumption and stocking rate were evaluated. Forage samples were collected by hand plucking simulation to determine organic matter, crude protein, neutral detergent fiber and total digestible nutrients. The inoculation had no effect on the parameters of forage mass. Inoculation provided increases in forage yield, protein and energy and stocking rate.