A platform for research: civil engineering, architecture and urbanism
Potential for high contribution of urban gardens to nutrient export in urban watersheds
Graphical abstract Display Omitted
Highlights Compost application to gardens comprises a large phosphorus input to the urban landscape. Gardens can be significant contributors to watershed P export if compost inputs are high. N runoff is mostly from lawns near streets, but garden compost can be an important contributor.
Abstract Urban gardens and farms typically use compost as a source of nutrients, often at levels that exceed crop nutrient demands. Although land dedicated to agriculture is a small fraction of urban land use, high input rates coupled with low nutrient use efficiencies suggest that export of nitrogen (N) and phosphorus (P) from this land could be potentially important contributors to urban nutrient budgets. We used the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Nutrient Delivery Ratio model to examine the potential impact of garden density, compost input rates, and nutrient retention efficiency on N and P export from stormwater runoff for a 737-ha urban residential area in Saint Paul, Minnesota. Although gardens and farms accounted for 0.1-0.5% of land area in our scenarios, compost inputs accounted for as much as 33% of N inputs and 85% of P inputs to the urban landscape. The contribution of gardens to urban nutrient export through stormwater runoff is highly dependent on modeled maximum retention efficiency values. If retention efficiency is high, gardens with low compost inputs are similar to other vegetated land uses in contributions to nutrient export, but gardens become significant contributors to watershed P export if compost inputs are high, or if retention efficiency drops to 75% or lower. These results underscore mass-balance constraints inherent in urban nutrient recycling and highlight the importance of understanding the long-term fate of excess nutrients applied to urban landscapes.
Potential for high contribution of urban gardens to nutrient export in urban watersheds
Graphical abstract Display Omitted
Highlights Compost application to gardens comprises a large phosphorus input to the urban landscape. Gardens can be significant contributors to watershed P export if compost inputs are high. N runoff is mostly from lawns near streets, but garden compost can be an important contributor.
Abstract Urban gardens and farms typically use compost as a source of nutrients, often at levels that exceed crop nutrient demands. Although land dedicated to agriculture is a small fraction of urban land use, high input rates coupled with low nutrient use efficiencies suggest that export of nitrogen (N) and phosphorus (P) from this land could be potentially important contributors to urban nutrient budgets. We used the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) Nutrient Delivery Ratio model to examine the potential impact of garden density, compost input rates, and nutrient retention efficiency on N and P export from stormwater runoff for a 737-ha urban residential area in Saint Paul, Minnesota. Although gardens and farms accounted for 0.1-0.5% of land area in our scenarios, compost inputs accounted for as much as 33% of N inputs and 85% of P inputs to the urban landscape. The contribution of gardens to urban nutrient export through stormwater runoff is highly dependent on modeled maximum retention efficiency values. If retention efficiency is high, gardens with low compost inputs are similar to other vegetated land uses in contributions to nutrient export, but gardens become significant contributors to watershed P export if compost inputs are high, or if retention efficiency drops to 75% or lower. These results underscore mass-balance constraints inherent in urban nutrient recycling and highlight the importance of understanding the long-term fate of excess nutrients applied to urban landscapes.
Potential for high contribution of urban gardens to nutrient export in urban watersheds
Small, Gaston E. (author) / Martensson, Niklas (author) / Janke, Benjamin D. (author) / Metson, Geneviève Suzanne (author)
2022-10-01
Article (Journal)
Electronic Resource
English
Online Contents | 2011
|Evaluating nutrient impacts in urban watersheds: Challenges and research opportunities
Online Contents | 2013
|British Library Conference Proceedings | 1998
|TIBKAT | 2006
|Economic Model for Urban Watersheds
ASCE | 2021
|