Green manure crops play an inportant role in organic farming. Field experiment was conducted at paddy soi1 (fine loamy, mixed, nonacid, mesic family of Aeric Fluvaquentíc Endoquepts) ín 2008/2009 to 2009/2010 at the Natíonallnstítute of Crop Science (NICS), RDA, Suwon, Gyeonggí provínce, Korea. This expe꺼ment was carried out to evaluate the biomass of haíry vetch (Vicia víllosa) and growth of rice (Oryza satíva) by cjífferent seedíng rates. Seeding rates of hairy vetch consisted of 30, 60, and 90 kg ha-' by broadcasting before rice harvesting. The biomass af)d nitrogen production of hairy vetch were not significantly different between 60 kg ha-’ and 90 kg ha-’ of seeding rates. Also, rice yield was not siginicantly differnt between seeding rate 60 kg ha-’ of hairy vetch and conventional pratice for two years. Therefore, we suggested that seeding rate of hairy vetch should be reduced by continuous cropping and incoportion of hairy vetch under rice-based cropping system.

• Jeon, W.T.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Seong, K.Y.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Oh, I.S.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Jeong, K. H.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Lee, J.K.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Choi, B.S.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Kim, C.G.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Lee, Y.H.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)
• Kang, U.G.(Divsion of Crop Environment, Nationallnstitute of Crop Science, Suwon 441-857, Korea)