摘要：Star forage chopper machine (SFCM) was modified and tested to reduce the powerrequired and to improve forage cutting efficiency, also, it will re-duce the environmental and health impacts by re-placing diesel-based farm machines with electrically operated ones. Power transmission assembly, rotat-ing cutter head knives and straw outlet position mod-ified, and newly constructed feed rollers were added and positioned to control plant material chopping process. The performance of SFCM was evaluated based on its ability to chop rice straw and cotton stalks under three different feedrates 0.8,1.2 and1.5 t/h four different knife speed,78.6(750),91.1(1000), 115.2(1250) and 136.2(1500) m/s(rpm). Minimum cut lengths were 1.35 and 1.27 cm for rice straw and were achieved by using the highest feed rate of 1.5 t/h with the maximum of knife speed 136.2 m/s with using toothed blades and normal (flail)blades re-spectively. At higher feed rates, either power re-quired cutting rice straw or cotton stalks increased with increasing knife speed under the two types of new knifes. Minimum power required to cut rice straw were 1.81 and 1.76 kW and were achieved by using feeding rate of0.8t/h with knife speed of78.6 m/s for toothed blades and normal (flail)blades re-spectively. Rice straw and cotton stalks cutting effi-ciency decreased with increasing feeding rates and increased with increasing knife speeds. Specific en-ergy for cutting rice straw and cotton stalks de-creased with increasing feeding rates and decreased also with increasing knife speeds.
