A monitoring system for an agricultural plant having a plurality of row units characterized in that it comprises: a seed meter； a seed conveyor belt having a forward facing side and a rearward facing side, said seed conveyor belt being arranged to receive seeds from said seed meter, said seed conveyor belt comprises a belt, said The belt has a plurality of spikes configured to carry the seeds, wherein said seed conveyor belt is configured to downwardly guide said forward facing side of said seed conveyor to a lower end of said seed conveyor belt. wherein said seed conveyor belt is configured to release seeds from said lower end, wherein said flights ascend said backward side without seeds； a first seed sensor mounted on said forward facing side of said conveyor belt, said first seed sensor is arranged to detect the presence of seeds and flights descending on said forward facing side of said conveyor belt； and a second seed sensor mounted to said rearwardly facing side of said conveyor belt, said second seed sensor is arranged to detect the presence of throws ascending from the rearwardly facing side of said conveyor belt. Monitoring system according to claim 1, characterized in that said first seed sensor comprises an optical sensor and wherein the second seed sensor comprises an optical sensor. Monitoring system according to claim 1, characterized in that it further includes: a monitor including a processor, said monitor being in data communication with said first seed sensor and said monitor being in data communication with said second seed sensor. Monitoring system according to claim 3, characterized in that said monitor is configured to record a first signal generated through said first seed sensor and wherein said monitor is configured to record a second signal generated through the second seed sensor. Monitoring system according to claim 4, characterized in that said monitor is configured to generate a corrected signal based on said first signal and said secon
