Crops: Corn for grain Corn for silage Cotton Hay Potato Rice Rye Ryegrass Sorghum Soybeans Sugar beets Sugarcane Winter wheat Wheat
4R Practices: Metadata Project
Assessing the Effects of Conservation Practices and Fertilizer Application Methods on Nitrogen and Phosphorus Loss from Farm Fields – A Meta-Analysis
Lead Researcher:
Dr. Song Qian
Associate Professor
University of Toledo
Start Date: 2014
End Date: 2016
Collaborating scientists and universities
- Dr. R. Daren Harmel, USDA-ARS
Matching Funds
- University of Toledo Research Council
Project Summary
The project augments an existing database by (1) revising studies included in the existing database to update information about fertilizer application methods, as well as additional variables, and (2) updating the database with recent studies. The project documents the use of the propensity score method and the multilevel modeling approach in the context of meta-analysis. Results are applicable for improved assessment of agricultural practices and their effects on the environment and can be used for providing realistic parameter values for watershed-scale modeling.
Project Goals:
- Compile a large cross-sectional database to document existing studies on agriculture management practices
- Document the use of two statistical methods for meta-analyses, as well as the effects of various conservation practices and fertilizer application methods in reducing nitrogen and phosphorus loss from farm fields.
Project Results:
- Updated the MANAGE database and is in the process of achieving the objective of finding the effects of the two noted agricultural practices on nutrient loss.
- Significant reductions in total phosphorus loads leaving a field when conservation practices were implemented.
- 70 percent reduction in the amount of total phosphorus leaving a field using the 2007 version of MANAGE while current analysis of the October 2014 edition showed a 54 percent reduction in total phosphorus leaving the field.
- The application conservation practices to a field reduce the amount of nutrient loss leaving a field.
Annual Reports
2015
2016
Publications
- Qian, S. S., & Harmel, R. D. (2016). Applying Statistical Causal Analyses to Agricultural Conservation: A Case Study Examining P Loss Impacts. Journal of the American Water Resources Association, 52(1), 198–208. Read More
- Christianson, L.E., Harmel, R.D., Smith, D., Williams, M.R. and King, K. (2016), Assessment and Synthesis of 50 Years of Published Drainage Phosphorus Losses. J. Environ. Qual., 45: 1467-1477. Read More
- Christianson, L.E. and Harmel, R.D. (2015), 4R Water Quality Impacts: An Assessment and Synthesis of Forty Years of Drainage Nitrogen Losses. J. Environ. Qual., 44: 1852-1860. Read More
- Christianson, L. E., & Harmel, R. D. (2015). The MANAGE Drain Load database: Review and compilation of more than fifty years of North American drainage nutrient studies. Agricultural Water Management, 159, 277-289. Read More