Effect of Precision Drill Operating Speed on the Intra-row Seed Distribution for Parsley

Since vegetable crops are characterised by a small seed size, a large number of plants per unit area and a shallow drilling depth, seed drills have to satisfy all these requirements so as to enable good-quality drilling. Uniformity of seed size and shape has a considerable effect upon the drill precision, notably on the performance of drills with a mechanical drilling unit. The drill operating speed has a decisive influence on the quality and efficiency of the seeding process. Attempts are therefore made to increase maximally the operating speed and still achieve satisfactory sowing quality. The range of optimal speeds should be defined for each crop separately. The objective of this study was to find how the drilling speed affects the quality of sowing parsley (Petroselinum crispum Mill.) with the Stanhay precision drill S 870. An increase of operating speed leads to changes of the values of the drill performance indicators. Thus, an increase in operating speed results in a decrease of drilling precision because the intra-row seed spacing becomes larger than that required. The set seed spacing increased from 7·5 to 8·3 cm in parallel with increasing the drilling speed by 1·8 to 5·2 km/h, respectively. The best intra-row distribution of parsley seeds was recorded at the speed of 1·8 km/h. At this speed 80·4% of seed was sown at the required spacing. At 2·4 km/h, 79·3% of seed was sown, 79·4% of seed at a speed of 3·6 km/h, reducing to 76·6% at a speed of 5·2 km/h. Research results show that satisfactory drilling results were achieved at speeds ranging from 1·8 to 5·2 km/h.