From the home of tortured acronyms (i.e., the EU) a wealth of information has come out of the Optimising Subsidiary Crop Application in Rotations (OSCAR) project on cover crops and particularly undersown / subsidiary crops for which there is a dearth of research globally.
The FFC Bulletin reported on the program at its inception (2014 V4 October) and there is now a huge amount of detailed information on the site, including botanical and agronomic information over 100 cover crop species, and, a decision support tool, that asks a number of questions about your farm system and what you are wanting to achieve and then makes recommendations on what cover crops to use. While it is EU focused, so the climatic / geographical areas are only in the EU, it is still of great value to those elsewhere on the planet – just choose an EU region that is climatically similar to your own.
I consider the decision support tool to be a really valuable step forward in using the power of computers to actively help producers with decision making rather than just using the web as electronic paper.
And for those that like to get their hands dirty and read the source material, there are over 50 research papers on the site, nearly all of which are publically available (for restricted access papers, email the author and ask for an ePrint – most are very happy to send one and even happier to know people are interested in their research).
And finally there is an ever growing wiki which includes a wide range of cover crop related information, such as machinery, pest & diseases, pastures, etc.
So a wealth of information that is of value to everyone in agriculture: farmers, scientists, advisors, seed producers, plant breeders, NGOs, and agricultural machinery manufacturers.