Some links are:

https://en.wikipedia.org/wiki/Organic_farming

http://agritech.tnau.ac.in/org_farm/orgfarm_introduction.html

http://thenextgalaxy.com/8-disadvantages-and-advantages-of-organic-farming/

http://www.small-farm-permaculture-and-sustainable-living.com/advantages_and_disadvantages_organic_farming.html

www.googleimages.com