Field-to-stream nutrient management

Authors: Young, Eric

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2021
Publication Date: 3/17/2021
Citation: Young, E.O. 2021. Field-to-stream nutrient management. Meeting Abstract. Dairy Forage Research Center Webinar Series.

Interpretive Summary:

Technical Abstract: Farm profitability and environmental performance are closely tied to dairy nutrient management systems. Nutrient management aims to maximize crop nutrient uptake and minimize environmental losses for individual farm fields or zones within fields. Regulated farms or those receiving grants must develop nutrient management plans to reduce nitrogen (N) and phosphorus (P) loss to streams and groundwater. In cold climates, much of the annual runoff occurs during the non-growing season with heavy contributions from snow melt and mixed precipitation events on frozen soils. Directing the amount, form, timing, and physical placement of fertilizer and manures in relation to site-specific soil and weather conditions is necessary to optimize net farm returns and mitigate nutrient losses. Managing manure is critical since a substantial fraction of annual crop nutrient needs can be met with it, however, crop nutrient uptake and loss are highly dependent on application methods and timing. Liquid and semi-solid manures applied to the soil surface (unincorporated) are more vulnerable to N and P transport in overland runoff flows compared to injection or tillage-incorporation. Injecting manure into the soil of growing crops can help reduce N and P loss. Cropping system dynamics and cover crops also affect erosion, N, and P loss potential. In the Great Lakes and other high priority watersheds, maintaining riparian stream buffers in addition to cropland best practices are important for mitigating nutrient transport to streams. The webinar will highlight dairy system practices aimed at improving forage crop nutrient use efficiency while mitigating nutrient transport in runoff flows.