U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

Linking soil phosphorus to dissolved phosphorus losses in the Midwest

Author:
Emily W. DUNCAN, Mark R. WILLIAMS, Greg LABARGE, Lindsay A. PEASE, Norman R. FAUSEY, Kevin W. King, Douglas R. Smith
ISSN:
2471-9625
Subject:
agricultural runoff, agricultural soils, fertilizer application, highlands, losses from soil, nutrient content, phosphorus, phosphorus fertilizers, pollution load, regression analysis, risk, screening, water quality, Ohio
Abstract:
Harmful and nuisance algal blooms resulting from excess phosphorus (P) have placed agriculture in the spotlight of the water quality debate. Sixty-eight site years of P loading data (combined surface runoff and tile flow) from 36 fields in Ohio were used to see if a soil test P (STP) concentration could be identified that allowed P application while still meeting recommended loss thresholds. Regression analysis revealed that P application to soils with STP concentration in the “critical level” range would result in P losses above the recommended Annex 4 thresholds. In addition, fertilizer application increased the risk of dissolved reactive P (DRP) loss as compared to years in which fertilizer was not applied. We determined that STP was a good screening method to identify fields that are at risk for greater P loss, but STP alone was not a good predictor of DRP loss, suggesting that a more holistic approach that includes upland management, edge-of-field practices, and in-stream approaches will be required to decrease DRP loading.
Agid:
5801831
Handle:
10113/5801831