Unfortunately, there is not a lot of good, current stuff.
Ironically, the biggest problem was that almost all of the sites covering Organic farming appear to be pro-organic web sites, with a smattering of web sites promoting non-organic farming techniques. However, virtually every web site that I saw (including the pro-organic) claimed that organic farming required more labor and produced less yield while generating more money due to the premium for organic produce.
I didn’t find anything that I would consider to be unbiased authoritative; although this is somewhat due to the nature of the agricultural business.
I found a Forbes article that discusses the lower productivity of Organic farming. However, Forbes is not what it once was, in terms of being an authority.
Here’s an article from the Washington State University’s Center for Sustainable Agriculture discussing the environmental benefits of Organic farming techniques - but warning that the benefits seem to be valid when compared by acre to acre, but not from unit to unit.
http://csanr.wsu.edu/organic-farming-environmental-benefit-yield-cost/
The Google Search term that I used to find this was “Organic farm yield”. I also tried “production of organic vs traditional farms” which found a lot of results, but they seemed to be fairly low quality. (Although, again - the low-quality sources all seemed to concur that Organic farming produces less yield per acre, across most forms of agriculture.)
