TOPIC: erratic emergance???

Started my first wild sim patches 6 years ago some started of great and some had few to no seng sprouts...this spring my best patches seem thin (dont have a poaching problem though deer and turkey abound)...anyway, this year my faithfull would be \"money making\" patches are thin...and my former poorly emergant patches have many 3 and 4 prongers some bearing seed...is it possible for some patches to take a season or two off and then come back strong...and vice-versa seems that's what's happening m, please advise. Thanks!