GROWTH AND BIOMASS PRODUCTIVITY OF FIBRE SORGHUM (SORGHUM BICOLOR) UNDER DIFFERENT AGRICULTURAL INPUTS AND MANAGEMENT PRACTICES IN CENTRAL GREECE

摘要

A two factor split plot field experiment in three blocks was carried out with fibre sorghum (Sorghumbicolour) grown on a fertile clay loamy soil in central Greece (Thessaly plan), in 2008-2009. Two dressings of N (0,150 kg ha~(-1)) were combined with either incorporating in the soil or harvesting Vicia faba, which was cultivated ascover crop before the sowing of the energy crop. The control plots were left without legume cultivation duringwinter. All fertilization plots were maintained at the same spot during the entire experimental period. Growth (e.g.plant height, CGR and LAI) and dry biomass productivity (total dry biomass and stem dry biomass) was monitoredby means of subsequent destructive samplings manually realized throughout the growing period of fibre sorghum.Sorghum total dry biomass fluctuated from 23 to 27 .5 t ha~(-1) for the monocrop systems depending on the nitrogendressings. These yields increased substantially to 27.7 – 30.2 t ha~(-1) for sorghum when faba bean was incorporated intothe soil before the sowing of the energy crop. Plant high and leaf area index were also significantly affected by fababean intercropping. Maximum plant height was obtained in the inorganic fertilized plots, but noticeable high rates ofplant height increase of up to 5.5 cm day-1 were recorded for plots with only faba incorporation, reaching final plantheight of 400 cm. Similarly to plant height, the LAI increased at considerable higher rates, reaching maximum valuesabove 6.4 m~2 m~(-2) in all cases of faba bean intercropping.