A new study reveals that these early agriculturalists were fertilizing their crops with manure 8000 years ago, thousands of years earlier than previously thought. So how did early farmers figure out that spreading manure was a key to farming success? Bogaard says that there are several plausible scenarios. Areas of “natural dung accumulation,” where animals hung out, would have provided “patches of superfertile ground that early crops would have colonized,” she points out, adding that “subsistence farmers are extremely observant of small differences in growth and productivity among their plots.” Click here for more information.