Middle-East Journal of Scientific Research 8 (4): 732-738, August 2011 ISSN 1990-9233 © IDOSI Publications, 2011 Corresponding Author: E. Tola, Precision Agriculture Research Chair (PARC), College of Food and Agricultural Sciences, King Saud University. P.O. Box 2460, Riyadh 11451, Saudi Arabia. 732 Development of an Opto-Electronic Monitoring System for Crop Planter Seed Metering Unit O. Hajahmed, E. Tola, K.A. Al-Gaadi and A.F. Kheiralla 1 2 3 4 Tital Company Ltd, Obeid-Khatim Street, 11192 Khartoum Sudan 1 Precision Agriculture Research Chair (PARC), College of Food and Agricultural Sciences, 2 King Saud University. P.O. Box 2460, Riyadh 11451, Saudi Arabia Department of Agricultural Engineering, Precision Agriculture Research Chair, 3 College of Food and Agricultural Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia Department of Agricultural Engineering, Faculty of Engineering, 4 University of Khartoum, P.O. Box 321 Khartoum, Sudan Abstract: The main objective of a seeding machine is to put seeds at a desired depth and spacing within the row. Seed spacing uniformity is one of the most important criteria in evaluating planter performance. Therefore, the objective of this research work was to develop an Opto-electronic monitoring system for the assessment of a mechanical planter seed metering unit performance. The developed system was used to monitor seed flow from the metering system of the row crop planter and to determine seed spacing. The developed system comprised of an optoelectronic sensor for seeds detection, a rotary encoder for forward speed and seed position measurement, amplifiers for adjusting sensors signals, a microcontroller for synchronizing sensors signals and a PC for operating the program and displaying process. The opto-electronic monitoring system has been successfully developed and tested on chickpeas seeds at two operating speeds (1.3 ms and 1.9 ms ) 1 1 and three metering system gear combinations. Both seed numbers and positions of the dropped seeds were assessed. The results indicated that the developed system can be accurately used to detect seeds flow from the metering system with strong linear relationship between the system measured and the actual measurements (R = 0.993). Furthermore, the system could be easily modified to measure seed spacing on-the-go in order to 2 monitor both seed flow and seed spacing. Consequently, the developed system will enhance the process of precision seed placement. Key words: Opto-Electronic Sensor Precision Farming Seed Metering Seed Spacing INTRODUCTION Robinson et al. [3] studied the effect of uniformity of The main objective of a seeding machine is to put quality. They found that uniformity of plant spacing seeds at a desired depth and spacing within the row. within the row affected yield, seed size and consistency Uniform seed spacing and depth result in better of seed size in some of the sites and years of their study. germination and emergence and increase yield by Thus, both seed population and seed spacing at planting minimizing competition between plants for available light, time have effects on the harvested seed yield and seed water and nutrients; and the quality of horizontal and size. Examples of studies conducted to determine the vertical distribution of seeds is influenced by row effect of plant population on seed quality include projects spacing, sowing depth, soil conditions, seeders design, conducted by Robinson et al. [4] and Johnson et al. [5]. seed density and operator skill [1, 2]. Plant population is Both studies found that specific plant populations an important factor in crop production, which can provided maximum yield depending on test location. Both affect growth and yield and this to a great extent depends studies also showed that seed size generally decreased as on the performance of the metering mechanism. plant population increased. plant spacing within the row on sunflower yield and