During 2004-2006,a field experiment in the Huichuan domestication and cultivation base of Notopterygium franchetii was conducted to study effects of nitrogen and phosphorus fertilizers on yield of N.franchetii,extract content,and essential oil content.The yield of N.franchetii gradually increased with an increase of N or P fertilization.The extract content increased initially but then decreased as N fertilization increased while the opposite happened with an increase of P fertilization.Essential oil content...