Developing a Water Quality Monitoring Protocol for Cranberry Growers to Optimize Best Management Practices for Nutrient Retention

Commodities

Practices

Title: Developing a Water Quality Monitoring Protocol for
Cranberry Growers to Optimize Best Management Practices for
Nutrient Retention. Compared to most crops, cranberry
production requires very large inputs of water for irrigation,
harvesting, and crop protection, raising concerns about impacts
of nutrients from cranberry drainage on downstream water quality.
Cranberry growers have faced increasing scrutiny about water
quality impacts, yet very little is known about the nitrogen and
phosphorus exports from Upper Midwest commercial cranberry farms,
known as marshes. Due to their complex water management,
quantification of nutrient losses from cranberry marshes is
challenging. Marshes typically receive inputs of surface water
and/or groundwater for irrigation and flooding, which may be
retained and recycled using reservoirs, or released through
surface or subsurface flows to creeks or wetlands. To robustly
measure nitrogen and phosphorus inputs and losses to drainage
water, we propose to combine collaborative on-farm research with
measurements at a unique experimental setting at the Wisconsin
Cranberry Research Station. This facility has four cranberry beds
constructed over an impermeable liner that restricts groundwater
exchange, and surface water is drained through a single outlet,
enabling complete quantification of hydrologic nutrient losses.
The experimental data will provide the first rigorous
measurements of water quality impacts of an Upper Midwestern
cranberry marsh operated under best management practices. In
addition, we will collaborate with cranberry growers to measure
water quality within and among three diverse commercial marshes,
and will develop and test a practical sampling method to measure
and optimize practices to improve water quality. Commercial
marshes were selected to span a range of geographic locations,
including an intensive agricultural landscape with nutrient-rich
water sources. Comparisons of water inputs and outputs among the
commercial marshes allows us to test whether cranberry marshes
might be strategically managed to improve water quality,
analogous to constructed wetlands. Overall, the project will
enable Upper Midwest cranberry growers to assess and improve
their management practices with respect to water quality, thereby
benefiting the long-term economic and social sustainability of
the industry as well as the environment. Project Coordinators
(Hall and Atucha) are Extension-funded faculty at UW-Madison and
will engage closely with members of the Wisconsin State Cranberry
Growers Association through field days, webinars, and extension
publications, in addition to producing a peer-reviewed scientific
article. Findings will also support development of a module in
the cranberry nutrient management training offered by the
Wisconsin Department of Agriculture, Trade and Consumer
Protection.

Objective 1: Evaluate magnitude and timing of nitrogen and
phosphorus losses from cranberry drainage water. 

Objective 2: Develop a protocol for growers to document nutrient
inputs in water used for production, nutrient outputs in drainage
water, and their relationship to management practices.

Objective 3: Develop extension programming on water quality for
the cranberry industry.

Learning and action outcomes: Cranberry stakeholders will learn
about water quality interpretation and monitoring protocols for
commercial cranberry production. This will inform potential
changes in water management and nutrient inputs, improving
surface water quality. Outcomes will be evaluated using pre- and
post-project surveys.