Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: November 4, 2004
Publication Date: November 4, 2004
Citation: Delate, K., Cambardella, C.A., Burcham, B., Mc Kern, A. 2004. Beyond agronomics: Neely-Kinyon long-term agroecological research (LTAR) results in year six [CD-ROM]. Madison, WI. ASA-CSSA-SSSA Annual Meeting Abstracts.
In the sixth year of the Neely-Kinyon Long-Term Agroecological Research (LTAR) site (2003), certified organic corn (Zea mays L.) yield at 7.5 Mg/ha was statistically equal to conventional corn yield, and organic soybean [Glycine max (L.) Merr.] yield at 2.2 Mg/ha was comparable to conventional soybean yield. These yields were considered excellent, particularly during a period of very low rainfall in July and August. Grass and broadleaf weed populations were greater in organic fields, but effect on yield was negligible. Bean leaf beetle populations were low, averaging 2.3% seed staining. The lack of seed staining led to an organic selling price of $17/bushel, leading to a 150% overall increase in returns from organic production. In addition to economic benefits, environmental benefits included greater particulate organic matter-carbon (POM-C) and particulate organic matter-nitrogen (POM-N) in the organic system relative to the conventional system, despite the relatively high tillage intensity in the organic system. Microbial biomass carbon (C) was not different among the various systems, but potentially mineralizable nitrogen (N) was significantly greater in the organic system. Economics favored certified organic production at this site in the first six years of the LTAR, with no depression in yields during the required 3-year transition period.