THE INFLUENCE OF LATERAL WIND SPEED ON THE UNIFORMITY OF GRAIN DISPERSION IN THE STUBBLE BEHIND THE COMBINE HARVESTER
Keywords:
straw chopper, chopped straw spreader, barley grain, harvesting.Abstract
The hypothesis of this study is that the dispersion of grain is not uniform over the cutting area of a combine harvester. In order to more accurately determine grain losses, troughs (collection boxes) should be placed across the entire cutting width of the combine harvester and even beyond. In addition, the speed of the lateral wind is likely to have a significant influence on both straw and grain dispersion. The aim of this study is to compare the distribution of barley grain in the stubble (cutting width) as a function of the lateral wind speed between barley grain extracted by the combine harvester and barley grain spread by the spreader rotors.
A Case-IH 9250 AFS combine harvester with a rotary threshing-separation device and a twin-rotor vertical chopped straw spreader was investigated. The research was carried out in 2023 in a spring barley field in the Kėdainiai district of 'Žibartonių' agricultural company. The boxes used for the tests were 500 × 380 mm grain, chaff and chopped straw collection boxes with a height of 100 mm. The time chosen for the tests was when the lateral wind was 2.00±0.48 m s ̶ 1 and when the lateral wind speed had increased to 8.00±0.86 m s ̶ 1. In the tests, nine collection boxes are positioned in front of the steering wheels of the combine harvester while it is running. The boxes are dropped not only within the cutting area (every 2 metres from the centre of the combine harvester) but also outside the harvester in both directions at a distance of 1 and 2 metres (on stubble of 8 to 10 cm and in the unharvested field). Each test was repeated 3 times. The tests showed that in a lateral wind of 8.00±0.86 m s ̶ 1, 86% of the grain is spread from the middle of the combine to the windward side and about 14% of the grain flies against the wind direction. In a lateral wind of 2.00±0.48 m s ̶ 1, the grain is approximately 50% spread in both directions from the centre of the combine. The grain distribution of barley grain, as shown by the data obtained, shows that the distribution of grain behind the combine harvester spreader is influenced to a large extent not only by the correct adjustment of the spreader, but also by the strength of the lateral wind.
