Phosphorus Levels on Maryland Farmland Lower Than Expected, Still a Significant Risk to Bay Water Quality

Posted on March 22, 2016 Updated on March 22, 2016

The Maryland Department of Agriculture (MDA) released a report earlier this month on soil phosphorus levels on state farmland from the second half of 2015. The MDA found that 18% of Maryland’s farmland has soils oversaturated with phosphorus. While this percentage is not as high as was expected,** this is still a significant amount of state land contributing to phosphorus pollution in local waters- this is one out of every five acres of farmland statewide; and two out of three acres on the Eastern Shore, according to the Bay Journal (Wheeler, 2016).

Phosphorus pollution from agricultural fields is a major issue in Maryland, given the high number of poultry farms and poultry manure that is applied as fertilizer to nearby fields. When over-applied to farmland, fertilizer high in phosphorous (which poultry manure is), runs off into local waterways, and pollutes the Chesapeake Bay watershed.

Last year’s update to the Phosphorus Management Tool (PMT), and the 2016 Poultry Litter Management Act, which has yet to be voted on in the state General Assembly, are Maryland’s regulatory attempts to solve this pollution issue. These regulations would transport phosphorus-laden fertilizer to farmland elsewhere in the state where phosphorus levels are low. The MDA report stated that 82% of farm fields have lower phosphorus levels, excluding these fields from the PMT regulation- meaning these farms will be allowed to continue to apply fertilizer as usual.

The 18% of fields found to have oversaturated soils (high in phosphorus) will be subject to PMT regulations. This targets farmland on the Eastern Shore- two thirds of farmland on the Eastern Shore will be subject to PMT restrictions- and the Lower Eastern Shore in particular, where 11% of farmland is subject to restrictions on phosphorus fertilizers altogether (Maryland Department of Agriculture, 2016).

**Keep in mind that the report gets its data from samples taken on state farmlands, and data is incomplete. The document does not account for 30% of state soils due to a lack of reporting. Half of missing data comes from the Eastern Shore- the portion of Maryland where poultry production is highest, and soil phosphorus levels are of the biggest concern.