Impact of wheat stubble height on combine technological parameters

Abstract

This paper presents the impact of wheat stubble height on combine technological parameters. Generally the wheat is cut leaving approximately 100 mm stubble height. It has been determined that at the beginning of the harvesting period when the average moisture content of the wheat stems is 740 mm length is 40.5%, 100 mm height stubble mass comprises 24.2±1.9% of all the stem mass and its moisture content is equal to 59.4±2.7%. During wheat harvesting the moisture of the stubble is approximately 1.4 times greater than that of the straw supplied into combine. This difference gradually decreases during harvesting. When the stubble height of wheat Ada was increased from 100 mm to 200 mm the less straw mass of 29.5±2.7% was supplied into combine, and the moisture of straw mass was about 50% less than the stubble moisture. Thus combine speed rate was about 1.2 km h-1 greater and during the same time it harvested 0.84 ha h-1 extra wheat. When wheat stubble was 200 mm the combine Class Lexion 540C motor consumed 4.7±0.8 l h-1 less diesel fuel if compared with fuel consumption when 100 mm stubble height was left. The further increase of stubble height does not show significant minimization of combine fuel consumption.