Your copy of the Quran seems to be a bit dodgy.
The whole statement reads:
Your wives are as a tilth unto you; so approach your tilth when or how ye will; but do some good act for your souls beforehand; and fear Allah. And know that ye are to meet Him (in the Hereafter), and give (these) good tidings to those who believe.
I think this is a clear indication that a man can demand sex whenever he wants it but with the caveat that he must do something good before and fear Allah over what he does.
thanks to anyone with a final answer
The final answer is that statements must be read in full and within context.
In this case it seems obvious to me that while a man is physically able to demand sex (description of fact), he must not do so in ways that would cause Allah to see reason to punish him (instructions regarding how to deal with the fact).
Don't forget that the Quran is not a simple list of laws. It also contains text that simply describes the situation the law applies to.
The Tora is similar in that regard.
The comparison of a wife with "tilth" is about value, not property rights. In Arab society owning a peace of cultivated land represented wealth. Referring to a woman as "tilth" back then is similar to calling a woman "honey" or "dear" or comparing her to valuable commodities like gold.
Perhaps a more modern interpretation of the text, with words adapted to western society and modern times, would be:
Your wives are the dearest to you; so approach your most precious when or how you will, but do something good before you do; and remember that G-d is watching you. And remember that you must explain yourself to Him (after death), and tell others about this.
I cannot see the Arabic text at the moment and thus cannot tell you whether the "you" is plural or singular. I think it's plural and refers to all men (and their respective wives).