Evaluating Planter Performance--Cotton Seed Placement Accuracy

Abstract

Row crop planter performance was investigated in a field study. Specifically, tests wereconducted to quantify intra-row seed spacing variability, and to isolate its sources. A planter wasinstrumented to allow in-field measurement of seed drop timing at two locations in the seed tube. Inaddition, seed spacing in the furrow was measured by hand. Tests were conducted while operatingthe planter at ground speeds of 4.8 km/hr (3.0 mph), 7.2 km/hr (4.5 mph), and 9.7 km/hr (6.0 mph).Seed meter rotational speeds of 0.16, 0.23, and 0.31 rev/s were achieved using a hydraulic drive andcontroller. Both cotton and corn seeds were planted. Results given in this report are limited to thoseobtained while planting cotton seeds with a meter rotational speed of 0.16 rev/s. The planterevaluated performed well under those conditions. Quality of Feed Indices ranged from 76.2 to91.4%. Maximum standard deviation of normally sown seeds was 6.1 cm (2.4 in.). The largestcomponent of spacing variability was introduced above the upper-most seed sensor, possibly by theseed meter. As expected, variability increased as each seed traveled toward its final resting place,however increases were not dramatic. Variability increased with increasing ground speed, as wasalso expected. Complete results will be forthcoming after additional data analysis.