Here is an interesting argument from a northern New Jersey columnist: the state’s effort to conserve open space by offering a tax break for farmland has left most of the open farmland in the hands of the wealthy.

It’s in the New Jersey Constitution, has been since 1963. Farmland is assessed for property taxes at its agricultural value, not its development value. To qualify, the property has to be at least five acres. Subsequent laws require that it generate at least $500 a year in agricultural revenue.

The goal was and is to preserve some of New Jersey’s diminishing stock of open land before it is all turned into condos and McMansions.

The program is working. But open land costs so much that the people who can afford to buy it tend to be well-to-do. This is unfair, critics say, because it enables rich people to surround themselves with open space and views while real, dirt-under-the-fingernails farmers are forced out of state…

Unsurprisingly, some owners of such New Jersey properties are megabucks celebrities. The rock star Jon Bon Jovi owns seven farm acres in historic Middletown, near the shore in Monmouth County, on which he paid $104 in taxes in 2010. Steve Forbes, magazine publisher, paid $2,005 in taxes in 2009 on 450 acres in Bedminster, in the Somerset Hills.

And here are former Gov. Christine Todd Whitman and her husband, John, who own 167 acres in Tewksbury, in Hunterdon County, on which they paid $1,521 in taxes in 2010, and 65 acres in Bedminster, on which they paid $173.

This sounds like a situation of unintended consequences: the law was intended to keep farmland open in the midst of suburban development but because of rising land prices plus tax breaks, the wealthy benefit.

Of course, there are other ways to conserve open space in the face of development. Contrast the approach in New Jersey versus the actions of the DuPage County Forest Preserve. After World War II, the Forest Preserve was very aggressive in grabbing open land, particularly land around waterways. If I am remembering correctly, by the late 1960s the Forest Preserve had over 15,000 acres in a rapidly expanding county that grew from almost 155,000 people in 1950 to nearly 492,000 in 1970 to over 904,000 in 2000. This didn’t come without a cost: the Forest Preserve had to find money to fund these purchases and there were complaints about rising local taxes plus the debt taken on in bonds. Additionally, the Forest Preserve ended up in several tussles over land with municipalities as both the County and suburbs wanted to control land before it disappeared. Today, there are still complaints about the Forest Preserve as the over 25,000 acres are maintained with taxpayer dollars. At the same time, there are a number of very nice sites and the land, unlike farmland, is open for everyone to use.

So if it came down to providing tax breaks  for the farms of wealthy landowners or having facilities that are taxpayer supported but also available to all, which would you choose? Presumably there are other options to choose from as well?