Submitted to: Soil and Water Conservation Society
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2007
Publication Date: July 10, 2007
Citation: Smith, D.R., Huang, C. 2007. Nutrient Losses from Row Crop Agriculture in Indiana. Soil and Water Conservation Society 2007 Annual Conference. July 21-25, 2007, Tampa, FL. 2007 CDROM. Technical Abstract: Topic: USDA CEAP: Research Results and Recommendations Nutrient losses from row crop agriculture are known to contribute to water quality problems such as eutrophication and the zone of hypoxia in the Gulf of Mexico. Fields and catchments in the Cedar Creek sub-watershed of the St. Joseph River basin were monitored water quality between 2002 and 2006. Approximately 80% or more of the land in the catchments were in row crop agriculture, primarily corn or soybeans. Most fields in this region are tile drained and the drainage water is conveyed to managed ditches. When evaluating 7 sites ranging from 299 to 4415 ha there was a tremendous range in nutrient loads. In 2004, NO3-N loads ranged from 1.6 to 25 kg ha-1, whereas NO3-N loads in 2005 ranged from 0.2 to 9.3 kg ha-1. Precipitation and runoff were much lower in 2005 than in 2004. Soluble P loads ranged from 0.04 to 0.59 kg ha-1 in 2004 and from 0.007 to 0.17 kg ha-1 in 2005. The watersheds from which the greatest NH4-N, NO3-N, TKN or soluble P loads were observed in 2004 were also the ones from which the greatest loads from these nutrients were observed in 2005. This indicates that aside from precipitation and runoff, land use and management is likely the predominant factor controlling nutrient loads. As part of the Conservation Effect Assessment Project in Indiana, these data will assist land managers and policy makers in developing strategies to better manager our natural resources to protect water quality.