Abstract

Field measurements of header losses while harvesting different grain crops, mainly wheat and barley, were performed in Sweden during the harvesting season in 1986. In addition, divider losses in rapeseed were studied on one occasion. Different settings, e.g. reel speed index, reel height, stubble height and forward speed were varied. The header losses were collected manually, cleaned and weighed. The moisture content was measured to make it possible to convert the sample weights to 15 % moisture content (in rapeseed to 18 % water content). At each setting the header losses from a total of 7.5 m2 were collected. This area was divided into 15 plots, each of 0.5 m2. Sometimes also header losses from the divider area were collected. In rapeseed, the losses were collected in chutes placed in the gap between the crop rows. Nine chutes were placed in three adjacent gaps, three chutes in each. Each chute measured 10 cm x 100 cm. The gap between the rows measured about 25 cm. The header losses were divided into loose kernels and parts of or whole ears. In the experiments performed in seed crops most of the collected losses were ears. The header losses, apart from divider losses, were seldom of any magnitude. In most cases they were less than 50 kg/ha. However, in some cases they exceeded 200 kg/ha. Losses in the divider area were mostly of a more considerable size. In an upright standing crop, divider losses generally were between 150 and 300 kg/ha. In a lodged crop they were more than 1000 kg/ha in some cases. In general, divider losses were about 20 to 40 % of the total header losses. In a lodged crop they could make up more than 60 % of the total header losses. The experiments were unable to reveal whether the header losses, except for the divider losses, were constant along the cutterbar width. Neither could it be established whether there were any differences between different header constructions. Header losses increased rapidly in winter barley with increasing stubble height. This depends on the more or less broken straw that characterizes barley. Only a few experiments were made with different forward speeds. Header losses were generally larger at low speeds (about 0.5 m/s) than at normal speeds (about 1 m/s). Quite a few experiments were performed with different reel speed indexes. In general, least losses occurred at reel speed indexes between 1.2 and 1.6. In some experiments with different reel heights, the largest header losses occurred when the reel was positioned as low as possible. Least header losses occurred when the lowest position of the reel bats were level or slightly below the ears. One experiment with different divider equipment was performed in rapeseed. Divider equipment using a fender bar was not suitable in rapeseed. when this divider was mounted, the divider losses considerably exceeded those of the torpedo divider and vertical cutterbar. No particular difference occurred between the torpedo divider and the vertical cutterbar. With the vertical cutterbar mounted, losses tended to decrease with increasing forward speed.

Keywords

Skärbordsspill; spill; skördetröskning; spannmålsskörd

Published in

Rapport - Sveriges lantbruksuniversitet, Institutionen för lantbruksteknik
1988,
ISBN: 91-576-3523-4
Publisher: Institutionen för lantbruksteknik, Sveriges lantbruksuniversitet

Permanent link to this page (URI)

https://res.slu.se/id/publ/125632