I'll bet 1031 swap ratios peaked last year...

Looking back at all those 10-for-1 (or better) land swaps to build houses and Walmarts on, it may be as severe a distortion of value as "desert-state" house prices.

Toll Brothers Inc., the largest U.S. luxury homebuilder, reported a narrower second-quarter loss after writedowns for land, developments and options fell by almost $170 million. [More]

 Having chewed through those losses, I can't imagine CEO's and directors would be particularly gung-ho about bidding up adjacent farmland to build unwanted shopping centers.

“Although population growth is not an absolute prerequisite for successful investment and development, it certainly helps to work with rather than against trends…Meeting the demands of explosive, evolutionary growth requires sensitivity to urban form and sustainable designs - new communities that offer mixed uses, walkable environments, and access to jobs. The real estate implications of demographic changes around the world are enormous.” [more]

In fact, the hot new trend could be reclaiming space leapfrogged by developers in the ever-widening expansion of urban areas.  For one thing, sprawl may now be a health issue.

"As cities have expanded into rural areas, large tracts of land have been frequently transformed into low-density developments in a 'leapfrog' manner.... The physical environment of a community can support opportunities for play, an essential component of child development, and for physical activity, a health behavior that not only reduces risk of excess weight gain but also has many other benefits for overall well-being."
Our newer neighborhoods, the study concludes, don't do that.
The conclusion is clear, The health of our children is harmed by the environment in which we raise them. Hampton Roads - with the exception of parts of Norfolk, Portsmouth and a few villages - more often than not seems like one giant, sprawling suburb. Parts of Suffolk, where growth has been particularly rapid in the past decade, can seem like a collection of unconnected neighborhoods leading out onto overused thoroughfares.
Sprawl is the natural result of cheap gas and cheap rural land. Builders move their operations into the exurbs, where they can erect bigger and cheaper houses because neither the cost of land nor the cost of transportation exacts an obvious or immediate penalty. The true cost becomes clear only later.
Planners have long known that sprawl kills community, makes municipal services expensive to provide, and forces residents to drive farther and pollute more. Now, doctors are saying that it's also making our kids sick and dangerously heavy.
The reasoning on weight goes something like this: Because we build neighborhoods that are hard for children to navigate - and because schools have been mostly centralized - kids don't walk or bike for exercise or to get someplace. [More]

Try to wrap your mind around children walking to school or families walking to get an ice cream cone.  Pretty radical!  If energy prices return to nosebleed levels via market forces or emissions limits, the economics of denser populations will be overwhelming, and maybe some very enjoyable communities created.

Assuming I'm close to correct on urban development, who will be the heavyweights in the farmland market now? 

Try looking in a mirror would be my first instinct.