Cranberry Agriculture in the Watershed – understanding N impacts
Rachel W Jakuba, PhDScience Director, Buzzards Bay Coalition
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
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
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
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)
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
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 BBNEPLong Tail Pathway Closed Loop
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
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
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
Questions?
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