SEED LOCATION MAPPING USING RTK GPS

Abstract

The potential use of a real-time kinematics (RTK) GPS receiver for seed mapping with a high level of accuracywas investigated. High-accuracy seed mapping can potentially be used in weed control and plant-specific crop management.A four-row Salvo 650 vacuum planter was retrofitted with an RTK GPS receiver. Four seed detector sensors (one per plantingunit) were mounted directly above the planter shoes. These sensors detected the seeds as they fell through seed tubes. Twolow-cost single-board computers were used to acquire data in real time and display it in the tractor cab. The first computerwas interfaced to the RTK GPS unit to determine seed location and forward speed. The second computer was interfaced toa display unit mounted in the cab. The first computer obtained the GPS time and UTM coordinates every second and storedthem with a reference time (time tag). This computer also monitored the seed detector sensors, time-tagged the seeds fromeach unit, and stored the information in memory. The second computer monitored the first computer and reported the plantersperformance through the display unit mounted in the tractor cab. Field tests were conducted to check the performance of thisplanter over two growing seasons. The first year test results indicated a need to control the sensitivity of the seed detectorsensors used for seed detection. The second year tests showed that the improved system performed very well. The differencesbetween the actual plant and the seed map generated by the RTK GPS based planter were in the range of 30 to 38 mm.