Abstract

MIRALLES DE IMPERIAL, Rosario et al. Poultry manure amendment on forage shorgum as energy crop. Rev. Int. Contam. Ambient [online]. 2011, vol.27, n.3, pp.171-179. ISSN 0188-4999.

Forage sorghum could be an efective alternative crop for energy purposes in areas where water irrigation are limited. The ability of regrowth after cutting of this crop can enhance biomass production. The sorghum stems sugar content could be an added value for bioethanol production. Trial was carried out in a greenhouse with forage sorghum (Sorghum bicolor (L.) Moench) cv. Digestivo. Two sorghum plants (plant V and plant A) were cultivated per pot. The aim in this work was to study the effect of two fertilizer treatments: straw broiler litter (STBL) and sawdust broiler litter (SBL) at rates: 0, 1 and 2 and a mineral fertilizer treatment (M) N-P-K, 15-15-15, equivalent in N at rate 1. The variables studied were: total plant biomass V (green cutting plant + regrowth) (biomass V), total biomass plant A (mature plant + tillering) (biomass A) and in order to evaluate the sugar content of sorghum stalks we studied the variable percent (%) degree Brix (°Bx): in green plant V (°Bx V) and in mature plant A (°Bx A). We made a two-way analysis of variance (treatment and rate) for STBL and SBL. Treatment and rate were significant in biomass V and only rate for °Bx V. Treatment × rates were not significant in the variables studied: biomass V, biomass A, °Bx V and °Bx A. In this trial the highest dry matter (d.m.) biomass A were obtained with rate 1 for STBL and SBL but in case of d.m. biomass V were obtained with rate 0, control (C). The highest °Bx values were obtained with C in both plants; the °Bx V were double than the °Bx A. Sorghum had a positive response to fertilization with poultry manure with rate 1 to d.m. of plant biomass (A) but in d.m. green plant biomass (V) better results were obtained with C. The sugar content in juice stems (°BxV and °BxA) was in all cases highest in control with rate 0.

Keywords : Sorghum bicolor; straw broiler litter; sawdust broiler litter; biomass; Brix degree.