A DEVICE AND METHOD COMPRISING A LARGE SQUARE BALER WITH A PRE-COMPRSSION CHAMBER THAT ACCUMULATES HAY AND MOVES IT INTO THE COMPRESSION CHAMBER, ONE OR MORE NEAR INFRARED SPECROCOPY (NIRS) SENSORS MOUNTED NEAR THE TOP OF THE PRE-COMPRESSION CHAMBER, A MEANS TO READ INPUTS FROM THE SENSORS ONLY WHEN THE STUFFER FORKS ARE MOVING HAYFROM THE PRE-COMPRESSION CHAMBER INTO THE MAIN CHAMBER AND A PROCESSOR TO AVERAGE MULTIPLE READINGS FROM THE NIRS SENSORS FROM THAT INTEVAL.