This document summarizes a study looking at nitrogen impacts from cranberry agriculture in the Buzzards Bay watershed. It notes that cranberry is the dominant form of agriculture in the area and aims to better understand nitrogen contributions from cranberry bogs. The study will examine two common types of bog configurations over 14 months, measuring nitrogen and phosphorus concentrations before and after water passes through the bogs. The goal is to calculate nitrogen mass leaving the bogs and help reduce uncertainty around nitrogen loading from cranberry agriculture.

1. Cranberry Agriculture in the
Watershed – understanding N impacts
Rachel W Jakuba, PhD
Science Director, Buzzards Bay Coalition

2. Agriculture in the Landscape
• Agriculture can be a significant contributor to
N in coastal waters in SE MA, though
wastewater is typically the largest source of N
• Cranberry is the dominant form of agriculture
in the Buzzards Bay watershed
• While a low relative rate of fertilizer compared
with other crops they are closely connected to
waterways

3. Agriculture in the Landscape
• Agriculture can be a significant contributor to
N in coastal waters in SE MA, though
wastewater is typically the largest source of N
• Cranberry is the dominant form of agriculture
in the Buzzards Bay watershed
• While a low relative rate of fertilizer compared
with other crops they are closely connected to
waterways

4. TMDLs will require N reductions
• Many coastal waters around Buzzards Bay are
listed as impaired for N on 303(d) ‘Dirty
Waters’ list
• MA is required to developed TMDLs for these
waters that include plans for reducing N
• Massachusetts Estuaries Project develops a
target N threshold that a specific estuary can
handle and sources of N to that estuary

5. Distribution of N sources
• N reductions should be distributed across N
sources, so it is important to understand the
amount of N contributed from cranberry bogs
Agawam River subwatershed Wankinko River subwatershed
Data from Massachusetts Estuaries Project (Howes et al. 2013)

6. Challenges of managing N from bogs
• Variable process – N loss from cranberries
bogs is influenced by management practices
• Limited quantitative information – only two
scientific studies in SE MA on N loss from bogs
• Values from the two studies range by over 3-
fold for N loading

7. Reducing Uncertainty
• Study to look at 2 common bog configurations
• Partnership between Coalition, UMass Cranberry
Experiment Station, MBL, Town of Carver, Cape Cod
Cranberry Growers’ Association
• Funded by DEP and BBNEP
Long Tail Pathway Closed Loop

8. Basic study design
• Look at 3 examples of each
bog type (i.e., 6 bogs total)
• Collect data for ~14 months
• Measure N & P
concentrations in surface
and groundwater before
and after it reaches the bog
• Use water flow estimations
to calculate the mass of
nitrogen leaving the bogs

9. Basic study design
• Look at 3 examples of each
bog type (i.e., 6 bogs total)
• Collect data for ~14 months
• Measure N & P
concentrations in surface
and groundwater before
and after it reaches the bog
• Use water flow estimations
to calculate the mass of
nitrogen leaving the bogs

10. Study thus far
• QAPP outlining protocols approved by MA DEP
and EPA
• Sampling began in late September with
samples collected during the harvest floods
• Analysis of samples is underway
• Groundwater appears to be a significant sink
of N

11. Questions?