Location: National Soil Dynamics Laboratory
Title: Inorganic and organic nitrogen sources for optimal rye cover crop biomass production Authors
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: August 12, 2010
Publication Date: January 15, 2011
Citation: Balkcom, K.S., Arriaga, F.J. 2011. Inorganic and organic nitrogen sources for optimal rye cover crop biomass production [abstract]. Sustainable Feedstocks for Advanced Biofuels Workshop. http://www.swcs.org/documents/filelibrary/roadmap/SFAB_Program_and_Abstract_Book__FIN_8607CF9B02A16.pdf Technical Abstract: Winter cover crops are an integral part of conservation systems and have traditionally been utilized in the Southeast to protect soils by controlling erosion, improving infiltration, and increasing organic C inputs. Growers are encouraged to maximize biomass production, but are reluctant to apply N fertilizer to a cover crop not harvested for monetary gain, although potential benefits are enhanced. Utilizing a winter rye (Secale cereale L.) cover crop as an alternative energy source could justify higher N rates, and an organic N source, such as poultry litter, could be more sustainable. An experiment was implemented at the Wiregrass Research and Extension Center in Headland, AL on a Fuquay sand (loamy, kaolinitic, thermic Arenic Plinthic Kandiudults) during 2006-2008 to compare N fertilizer sources, rates, and time of application for a rye cover crop to optimize biomass production. Main plots were time of application (fall and spring), subplots were N source (commercial fertilizer and poultry litter), and sub-subplots were N rate (0, 34, 67, and 101 kg N ha-1 as commercial fertilizer and 0, 2.2, 4.5, and 6.7 Mg ha-1 as poultry litter on an as-sampled basis). Fall application of N fertilizer, regardless of source or rate, resulted in more biomass production. Poultry litter was comparable to fertilizer as an N source, but surface application may result in ammonia volatilization. As expected, the greatest biomass production (8000 kg ha-1) occurred with the highest N rate, but there was no difference between N sources. These results indicate that growers with access to poultry litter may utilize it as a substitute to costly N fertilizer for biomass production.