"If we attempt to change the model to "no till" and other nature friendly methods, the production will drop so drastically," Who told you that? Can you give any data to support it? Read on...
There is one point in there tedlin... we probably can't feed the world population with so few people working the land with organic/ natural methods. It's only since world war II that we drove so many farmers off the land, in favor of gigantic machinery that compacts the soil. Organic/ natural methods are more labor intensive. But with 10% of the country unemployed and at least 30% of the country obese, would it be such a bad thing to put some people back to work, doing healthy physical work in the fields?
But as far as what the LAND will produce (as opposed to the people) it is just a MYTH that the land can't produce as much if we don't keep using chemical methods. Are you reading One Straw Revolution (OSR) with the book club? He talks a little in the introduction about scarcity myths and fear keeping people tied to the ways they are used to.
The ways of gardening /farming we are talking about here are NOT less productive. If you took the amount of produce I will get from 3 4x8' beds on a per acre basis, I bet it would beat any farmer. OSR says the Japanese standard is 1/4 acre feeds a family of four. I am a member of a Community Supported Agriculture farm. It is 5 acres farmed totally organically. Those 5 acres feed 100 families that are members. My partner and I get a half share and we do not buy any other vegetables during the season. We buy some fruit and grain and other stuff, but all our veggies come from the CSA farm (and we are vegetarian, so veggies is most of what we eat!) and we put some by for winter. But lets get back to DATA:
So about yield... here's a great article I found on the whole question of can we feed the world organically. I recommend reading the whole article it is very enlightening https://www.cnr.berkeley.edu/~christos/articles/cv_organic_farming.html , but here's a few highlights from it of studies of organic vs industrial methods for yield:
Soybean production systems were also highly productive, achieving 40 bushels/acre. In 1999 however, during one of the worst droughts on record, yields of organic soybeans were 30 bushels /acre, compared to only 16 bushels/acre from conventionally- grown soybeans (Rodale Institute, 1999). "Our trials show that improving the quality of the soil through organic practices can mean the difference between a harvest or hardship in times of drought"
A comprehensive review of a large number of comparison studies of grain and soybean production conduct by six Midwestern universities since 1978 found that in all of these studies organic production was equivalent to, and in many cases better than, conventional
Corn yields were comparable in all three cropping systems (less than 1% difference) (Drinkwater, 1998). However, a comparison of soil characteristics during a 15-year period found that soil fertility was enhanced in the organic systems, while it decreased considerably in the conventional system. Nitrogen content and organic matter levels in the soil increased markedly in the manureâ€â€fertilized organic system and declined in the conventional system. Moreover, the conventional system had the highest environmental impact, where 60% more nitrate was leached into the groundwater over a 5 year period than in the organic systems (Drinkwater, 1998). [RBG - we have had a system where the farmers aren't paying for that kind of damage they create, so it isn't counted in the cost, but that won't work much longer]
ETC!!
What we now call conventional agriculture, which again has really only been "conventional" since the 1950's, will not even be possible much longer. It is very highly dependent on petroleum inputs for petroleum based synthetic fertilizers as well as fuel for the machinery. Petroleum prices have been kept artificially cheap for a long time through lots of subsidy. But as all the easy sources get exhausted and we have to go more and more to extreme extraction (drilling miles under the sea, tar sands, etc) the production costs and environmental costs get higher and higher and the actual cost will have to also. So we are going to have to learn some new-old ways.
Cities pretty much import all their food from the country right now, but they wouldn't have to. If lots more people did backyard gardening, rooftop gardening, community gardens in vacant lots etc, the cities could at least come very close to feeding themselves. It's been done before. In both World Wars the cities mostly fed themselves ("Victory Gardens") while agricultural production went to feed the soldiers.
PS cynthia... still be glad to see what you come up with !!
PS more... gotta quit now, I'm off to go to healthy physical labor in the fields at our CSA!

You pay for your shares with some $$ (much less than equivalent produce would cost in store) and some labor (15 hrs for the two of us for the season). If you can't do the labor, you can compensate by paying more $$.