Location

Paper Presentations

Start Date

30-8-2017 8:15 AM

End Date

30-8-2017 8:30 AM

Subject Area

Nutrient management, Water quality

Description

Abstract. Cranberry bogs make up an important part of the landscape, economics, and cultural heritage of SE Massachusetts. Because cranberry bogs use ponds and rivers as water sources and as discharge points, the control of runoff of both nitrogen (N) and phosphorus (P) to surface waters from cranberry farming is a concern for the health and management of fresh and estuarine waters in watersheds where cranberry bogs occur. We quantified the movement of N and P into and out of three cranberry bogs in the Weweantic and Wareham River Watersheds during one water year and annual cropping cycle. We combined measurements of water flow with measurements of dissolved and particulate N and P concentrations in different components of the annual farming cycle to estimate N and P input-output balances. Water budgets varied widely among bogs. Two bogs showed net movement of groundwater into the bog, one of which had very high inflow, and the third bog had net water flow into groundwater. Two bogs exhibited small net N imports (0.1 and 2.0 kg N ha-1) in fluvial exchanges and one bog exhibited substantial N export (12.6 kg N ha-1). Between 73 and 77% of all fluvial N exports exited in surface water during non-flood baseflows. Bogs exported between 2.1 and 4.5 kg P ha-1 in fluvial exchanges and 55 and 81% of all P export occurred during non-flood baseflows. High variability of net N exchange likely arose from the hydro-geographical setting in which the bogs occurred. The variation in the magnitude and direction of P exchanges was much less and depended less on bog setting. Given the finding of that most annual export of N and P occurred in surface water flows during times that water was not actively pumped onto or released from bogs, water management specifically aimed at N and P removal from the small but steady outflow of surface water during non-flood periods could be beneficial. Management might include additional storage time in ponds or increased naturalization of stream channels.

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Aug 30th, 8:15 AM Aug 30th, 8:30 AM

Nitrogen and Phosphorus Balances of Cranberry Bogs in Southeastern Massachusetts Coastal Watersheds

Paper Presentations

Abstract. Cranberry bogs make up an important part of the landscape, economics, and cultural heritage of SE Massachusetts. Because cranberry bogs use ponds and rivers as water sources and as discharge points, the control of runoff of both nitrogen (N) and phosphorus (P) to surface waters from cranberry farming is a concern for the health and management of fresh and estuarine waters in watersheds where cranberry bogs occur. We quantified the movement of N and P into and out of three cranberry bogs in the Weweantic and Wareham River Watersheds during one water year and annual cropping cycle. We combined measurements of water flow with measurements of dissolved and particulate N and P concentrations in different components of the annual farming cycle to estimate N and P input-output balances. Water budgets varied widely among bogs. Two bogs showed net movement of groundwater into the bog, one of which had very high inflow, and the third bog had net water flow into groundwater. Two bogs exhibited small net N imports (0.1 and 2.0 kg N ha-1) in fluvial exchanges and one bog exhibited substantial N export (12.6 kg N ha-1). Between 73 and 77% of all fluvial N exports exited in surface water during non-flood baseflows. Bogs exported between 2.1 and 4.5 kg P ha-1 in fluvial exchanges and 55 and 81% of all P export occurred during non-flood baseflows. High variability of net N exchange likely arose from the hydro-geographical setting in which the bogs occurred. The variation in the magnitude and direction of P exchanges was much less and depended less on bog setting. Given the finding of that most annual export of N and P occurred in surface water flows during times that water was not actively pumped onto or released from bogs, water management specifically aimed at N and P removal from the small but steady outflow of surface water during non-flood periods could be beneficial. Management might include additional storage time in ponds or increased naturalization of stream channels.