Investigations into yield monitoring sensor installed on indigenous grain combine harvester

An automated yield monitoring system consisting of one yield sensor, global positioning system (GPS), field computer with custom software, and header cut off switch was mounted on a self propelled indigenous grain combine harvester for real-time crop yield mapping, Four wheat fields were selected at the farm of Punjab Agricultural University, Ludhiana to evaluate the performance of the yield monitor for grain yield mapping. The yield maps were generated by using ArcGIS software from the data collected for four different wheat fields. Total area harvested was 1.92 ha comprising four fields having areas 0.72, 0.46, 0.28 and 0.46 ha respectively. On an average yield variations recorded for the all the four fields was having C.V. of 18.4, 24.0, 17.4 and 22.2% respectively. The overall results shows that yield variability existed even within the smallest field of 0.28 ha having C, V, of 17.4%. Yield variability among the four fields was also existing having standard deviation of 866.67 kg/ha and coefficient of variation (C.V.) 19.8%. The yield delay was recorded 15-17 seconds used in travelling of grains from header to main tank. It was also observed that the mean error was 6.85% and that maximum error never exceeded 9.48%, indicating acceptable accuracy of the yield monitor in wheat crop. The coefficient of correlation was 0.94 between yield monitor recorded data and actual weight, using Pearson linear simple correlation that was moderate.