Estimation of farm tractor performance as a function of time efficiency during ploughing in fields of different sizes

Tractors have to perform various agricultural tasks in fields of different sizes. While working, tractors consume large amounts of fuel and contribute considerably to pollution of the environment. This study provides a method for the estimation and comparison of tractor performance when ploughing is carried out in fields of different lengths. Tractor performance as a function of time efficiency is estimated during tests with a 160 kW Massey Ferguson MF6499 tractor performing soil ploughing operations. For characterisation of different field sizes, a time efficiency factor was introduced, which was expressed as the ratio between the duration of ploughing operation and the duration of the whole ploughing process including the non-working time. Ploughing of fields with lengths of 200, 300, 500, 750, and 1000 m resulted in time efficiency values of 0.56, 0.67, 0.78, 0.84, and 0.88, respectively. This study analysed the tractor productivity, power utilisation efficiency, fuel consumption, and CO 2 and CO emissions for five fields. These indicators were calculated using the tractor engine Electronic Control Unit (ECU) ‘Load Profile’ database. Regression analyses demonstrated that the tractor performance indicators perfectly correlate with the time efficiency factor according to either a linear or exponential equation model. It should be noted that the suggested method allows for better estimation and comparison of tractor performance indicators when ploughing is performed in fields with different width-to-length ratios.