The optimum Kinematics parameter value (K) as the ratio of rotary-cutter peripheral velocity to tractor forward speed, and the suitable stalk moisture content levels (MC %) were determined for the appropriate cutting and shredding sunflower stalk residues. The combined effects of five different levels of parameter (K) and three stalk moisture content levels on the shredder performance were investigated. The shredding performance of rotary-cutter was indicated in terms of stalks cutting length, the stalk height left after shredding, and field efficiencies. Moreover, machine energy consumed, and operating cost were also estimated. The obtained results showed the following important points:- -  The optimum kinematics parameter (K) level was 63.5, while the appropriate stalk moisture contents (MC %) was 13.8%.  Whereas each of the resulted stalk cut length, and stalk height left after shredding were minimum. In addition, cutting, shredding, and field efficiencies were found to be higher at these parameter levels. -  The Kinematics parameter of 63.5, 31.6 and 17.2 were accomplished small, middle and large average cutting length of about 7.0.14.2, and 22.0 cm respectively. The corresponding, average stalk height left after shredding were 9.4, 12.7.and 21.0 cm respectively. -  The computed field efficiency was ranged from 74.15 to 88.62% depending on reducing stalk moisture from 18.2 to 13.8%. While the obtained field efficiency was ranged from 83.88. to 93.79.62% depending on increasing kinematics parameter values from 17.2 to 63.5. As, the stalk moisture content was reduced from the upper to the lower level, the equivalent fuel consumed power was reduced from 37.8 to 30.0 kW, versus cutting energy consumption from 37.1 to 27.9 kW.h/fed. Using the rotary-cutter shredder for shredding sunflower stalks could saved 60: 85 % from the shredding operation cost, compared with manual shredding.