Effect of tracks and tyres on soil physical properties in a sandy loam soil

Abstract

<abstract> <bold>Abstract.</bold> Agricultural vehicles are getting heavy and compaction results in lower yields, poor soil structure and soil-water regimes. A number of studies have shown that the first pass causes the most damage and therefore care must be taken to ensure that when tractors enter the field they are fitted with the most appropriate running gear for the application and for the local soil conditions. Low Ground Pressure (LGP) traffic systems, including tyres and tracks, reduce the ground pressure under field traffic to minimise the risk of soil compaction. The aim of this study was to determine the effect of standard and LGP systems, including tracks and tyres on soil pressure and physical properties. The research objectives were to quantify the effect of 1) rubber tracks (16 tonne Cat Challenger 765C) compared to 2) standard tyres and 3) LGP specific tyres (12 tonne 290 HP Massey Ferguson 8480). Standard and LGP tyres were inflated to 1) high inflation pressures at 1.2 bar front, 1.5 bar rear, and 2) low inflation pressures at 0.7 bar front and rear. Soil pressure was measured using strain gauge pressure transducers at a depth of 300 mm in the centre of the wheel. Data were collected using a National Instruments CompactRio system and logged with virtual instrument software on a laptop PC. Soil physical properties were determined using a cone penetrometer. Peak soil pressures under the rubber tracks (0.27 bar) were significantly lower (<0.05) than under high inflation pressure tyre treatments (0.39 bar standard tyres; 0.48 bar LGP tyres). An increase in tyre inflation pressure resulted in an increase in soil pressure (0.39 to 0.42 bar in standard tyres; 0.36 to 0.52 bar in LGP tyres)This study concluded that both LGP tyres at low inflation pressure and tracks were suitable to minimise soil compaction on a sandy loam soil..