A seed spacing monitoring system (16) is used in an agricultural seeder (10) for planting seeds. The agricultural seeder (10) has a furrow opener (28, 52) a seed meter (36, 64) for metering seed to be dispensed in the furrow (18), and a furrow closer (34, 58) to cover the seed in the furrow (18). The seed spacing monitoring system (16) includes a detector (42, 68) supported to detect seeds in the furrow (18) prior to the seeds being covered. The detector (42, 68) provides a plurality of seed presence signals, with each seed presence signal being indicative of a respective seed present in the furrow (18). A speed sensor (19) is associated with the seeder (10) and provides a speed signal indicating a ground speed of the seeder (10). An electrical processor (16A) receives the plurality of seed presence signals and the speed signal. The electrical processor (16A) determines a seed spacing, dependent upon the seed presence signals and the speed signal.
