The effects of fertilisation and cultivation treatment combinations on sweet sorghum were studied at the Biomass Utilization and Crop Production Demonstration Centre of Szent István University (Szárítópuszta) in 2009. The trial field is located in the Gödöllő hills area. The field trial was conducted on poor quality rust-brown soil. The area has a continental type climate where extreme weather conditions are typical. The vegetation period had 133 mm of precipitation. The potassium and phosphorus supply in the soil is sufficient but the nitrogen supply is poor. The trial included four cultivation treatments (ploughing, cultivating, disking and direct sowing) and six different fertiliser treatments (50, 100 kg/ha N active ingredient; 40, 80 kg/ha K active ingredient). The sweet sorghum variety used in the trial was Sucrosorgho. Both the method of cultivation and the fertilisation had an effect on the amount of foliage and ethanol output per hectare. Where the level of active ingredient N was 50 kg/ha, the refractometric (Brix) dry matter content was increased by between 9.8% and 47.6% in the stem of sweet sorghum compared to the control treatment; at 100 kg/ha N the increase was between 9.7% and 32.0%. At 40 kg/ha K active ingredient it was between 8.5% and 17.6%, at 80 kg/ha K it was between 8.5% and 33.9%, whilst with combined fertilisers at 50 kg/ha N–40 kg/ha K it was between 9.2% and 34.4%, and at 100 kg/ha N–80 kg/ha K it was between 9.9% and 39.9%. The method of cultivation also affected the results. The additional foliage was 82% with ploughing, 57% with disking and 47% with cultivator treatment compared to direct sowing at control nutrient levels. Direct sowing was not successful for sweet sorghum in 2009 as the year was affected by drought. Additional experiments are necessary to show how the crop year affects the chemical properties of sweet sorghum.

Keywords: sweet sorghum, soil tillage, biomass, refractometric (Brix) dry matter content, ethanol-yield