In earlier research, vetch was shown to be the best legume for N fixation, and it is now grown commercially as part of the cropping system on some farms across most cotton growing regions. After nine years of research on a cropping systems experiment conducted at the Narrabri Australian Cotton Research Institute growing vetch as a green manure crop provided not only substantial nutritional benefits to cotton and improved soil structure, but also gave a greater economic return. This article reports the economic benefits of incorporating legumes into cotton cropping systems. Envelope>� �