As a result of spreading extreme quantities of manure on their fields, all but one industrial-scale chicken farm on Maryland’s Eastern Shore reported having at least one field saturated with “excessive” soil phosphorus, according to planning documents from 60 concentrated animal feeding operations (CAFOs) in six counties submitted between 2008 and 2014. Excessive values tell farmers they should not apply additional phosphorus since crops are not able to absorb it and it ends up running off of fields, into streams, and eventually into the Chesapeake Bay where it contributes to dead zones that have plagued the Bay for decades. New, science-based regulations would limit phosphorus application on farms with excessive soil phosphorus readings. The map above, which shows soil phosphorus levels (known as Fertility Index Values (FIVs)) on fields on which farmers spread manure, illustrates why the phosphorus management tool (PMT) is so desperately needed. Read more.