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Report, 2004

Dragkraftsbehov och bearbetningsresultat för olika redskap och bearbetningssystem vid höstsådd

Magnusson, Marcus

Abstract

Tillage involves great expense for many farmers today. Lowering machinery costs, fuel consumption and working hours per hectare can reduce total costs. However, this must be achieved without compromising the results of tillage. In a project carried out in the autumn of 2003, draught requirement and tillage outcomes were compared for different tillage implements during autumn sowing on a light soil and a heavy soil. The tillage implements used were mouldboard plough, shallow plough, stubble cultivator, heavy duty stubble cultivator with wing shares, tandem disc harrow and heavy disc harrow designed for shallow tillage. Except for the mouldboard plough, one and two passes were investigated for each implement. After primary tillage, the seedbed was prepared with a disc harrow for shallow tillage and a roller adapted for cultivation. Seed was drilled using a combi-drill with discs for shallow tillage. For each implement the fuel consumption was measured using an adapted tractor (Massey Ferguson 6290) with equipment for measuring fuel consumption. The equipment was calibrated to give the PTO effect for any combination of fuel consumption and engine speed. This effect was assumed to be equal to the effect available at the wheels. The drawbar power was calculated by subtracting power losses through wheel slip and rolling resistance. The draught requirement was calculated by dividing the drawbar power by the actual speed, which was measured during work. The actual working depth was calculated by measuring bulk density before tillage and then weighing the cultivated soil from a specific area. On the basis of the tillage depth, the working width and the draught requirements, it was possible to calculate the specific draught (force per cross-sectional tilled area, kN/m2). The draught per metre working width (kN/m) was also calculated and used to calculate the fuel consumption per hectare for the different systems. Some of the cultivated soil from each line was sieved into different fractions, allowing the approximate surface area of the tilled soil (m2/kg) and the energy requirement for fracturing (J/m2) to be calculated. After drilling, the soil surface was photographed and the images were analysed to calculate how much of the soil surface was covered with straw from the previous crop. To make a fair comparison of draught between different tillage implements, the actual working depth must be taken into consideration. The pre-set working depth is not an adequate parameter because the different implements do not leave equally uniform tillage bases. Therefore they till different volumes of soil at a particular pre-set working depth. The mouldboard plough and the shallow plough nearly always worked to the pre-set depth while the other implements always tilled to a shallower level than the pre-set depth. The mouldboard plough and the shallow plough had the lowest specific draught requirement. On the light soil, the specific draught did not differ much between the other implements. On the heavy soil, however, the specific draught was highest for the stubble cultivator and the heavy duty stubble cultivator with wing shares. The specific draught for the second pass was higher than that for the first pass for each implement because the actual working depth became very shallow. The mouldboard plough and the shallow plough were least effective at fracturing the soil, while there was little difference between the other implements. However, the tandem disc harrow and the heavy disc harrow designed for shallow tillage fractured the soil most effectively. The fracturing did not increase much after the second pass with any of the implements. The mouldboard plough and the shallow plough buried the straw best, while the direct drilling treatment left most straw on the soil surface. The differences between the other implements were low. The second pass did not seem to decrease the amount of straw on the soil surface. The tillage systems with the mouldboard plough and the shallow plough consumed the most fuel. Much of the fuel used in the overall tillage process is consumed in seedbed preparation. Both the tillage systems with the plough required more seedbed preparation than the other systems and that was one of the reasons why the fuel consumption was higher. The direct drilling system required the lowest amount of fuel. Of all the cultivation systems, those with one pass with the tandem disc harrow and the heavy disc harrow for shallow tillage consumed the least fuel. On the basis of all the parameters studied here, it is hard to identify an optimal tillage system. The choice depends on the prevailing conditions in the field in question. If there is a large amount of straw from the previous crop that is likely to cause problems, the mouldboard plough or the shallow plough are preferable because in such cases it is important to bury the straw well and this can justify the higher fuel consumption. The results of this study show that shallow ploughing (~11cm) with either of the two ploughs requires a lower amount of fuel, fractures the soil better and buries the straw as well as deep ploughing (~20cm). If the straw from the previous crop is not a problem, the system with the heavy disc harrow for shallow tillage or the heavy duty stubble cultivator with wing shares is preferable since both these implements give high soil fracturing and slicing across the entire working width, killing weeds effectively

Keywords

jordbearbetning; bränsleförbrukning; bearbetningssystem; höstsådd; dragkraftsbehov; sönderdelning; halmnedbrukning

Published in

Meddelanden från Jordbearbetningsavdelningen
2004, number: 47
Publisher: Institutionen för markvetenskap, Avdelningen för jordbearbetning

UKÄ Subject classification

Agricultural Science

Permanent link to this page (URI)

https://res.slu.se/id/publ/31098