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Report, 2006

Dragkraftsbehov och bearbetningsresultat för olika kultivatorspetsar

Hillerström, Olov


Reduced tillage is increasing among Swedish farmers, much caused by a poor profitability in cropping. In many cases the mouldboard plough is replaced by a shallow tillage implement, often a stubble cultivator. The cultivator has got tines, which consist of a shank and a share. There are many different kind of shares to choose from. To make the decision of the share model easier, a project was performed during the autumn of 2005 where draught requirement and tillage outcomes were studied for different kinds of shares. In a first project, different kinds of shares were tested on one heavy soil (50 % clay) and on one light soil (19 % clay). The tested shares were 80 mm, worned 80 mm, 80 mm winged, 210 mm and sweep. The remaining treatments were a stubble cultivator with vibrating tines and one mouldboard plough. In the second project shares with different width were compared on heavy soil (50 % clay). In all tests the specific (kN/m2) and total (kN/m) draught requirement was determined. Every test was done with a Massey Ferguson 6290 equipped with a fuel measuring system. A data logger continually registered the PTO-effect, wheel speed, radar speed and engine speed. The drawbar power was calculated by subtracting power losses through wheel slip and rolling resistance. The draught requirement was calculated by dividing with the actual (radar) speed. The total draught requirement was calculated by dividing the draught with the working width. The actual working depth was measured by the help of a metal frame, with an area of 0,25 m2, which was placed in the tilled plot, and in which all of the tilled soil was weighed. By measuring the bulk density the actual working depth could be calculated. When the actual working depth, the working width of the implement and the draught force were known the specific draught requirement could be calculated. From each treatment soil was collected and sieved into six fractions to be able to calculate the total particle surface per kg soil. By doing this a measure of the fraction capacity of the shares could be detected. The energy requirement for fracturing could now also be calculated. The straw remaining on the soil surface was estimated visually and determined by image analysis. Some of the measured draught requirement values were compared with values predicted by models. On the heavy soil the actual working depth became smaller than the pre-set depth for every treatment except for the shallow sweep treatment and the mouldboard ploughed treatment. On the light soil the mouldboard ploughed treatment, the shallow sweep treatment and the 210 mm share treatment had an actual working depth larger than the depth that was pre-set. It was shown that the actual working depth was increasing with an increasing share width. The 80 mm and 210 mm shares had the largest specific draught requirement on the heavy soil. The mouldboard plough and the shallow sweep treatment had the smallest specific draught requirement. On the light soil the worn 80 mm share had the largest specific draught requirement and the shallow sweep treatment had the smallest. The specific draught requirement was increasing with an increasing share width. The mouldboard plough buried the residual best while the shallow sweep left most straw on the soil surface. The correlation between measured and calculated values were generally low. Draught requirement for the mouldboard plough was generally overestimated by the model and values for the cultivator underestimated. The results show that both draught requirement and tillage outcome was very different between the share types. Further research would be valuable for both machinery manufacturers and farmers


jordbearbetning; dragkraftsmätning; dragkraftsbehov; kultivatorspets; reducerad bearbetning; bearbetningsresultat

Published in

Meddelanden från Jordbearbetningsavdelningen
2006, number: 51
Publisher: Institutionen för markvetenskap, Avdelningen för jordbearbetning

    SLU Authors

UKÄ Subject classification

Agricultural Science

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