The suitability of land for various types of burial varies. Presuming that the size of the plot required for burial plus a contribution to spacing between plots is 10' X 10', you have at most 435 plots. If your land is not perfectly rectangular, this will reduce the number of plots that can be fit into your land. Another thing to consider is the price of burial plots in that area of the cemetery. If it is a newer and more desired area, the cemetery might be willing to pay somewhat more. The cemetery will also have to develop your land, installing drainage and making other modifications. such as extending the fence to enclose your property . Suppose that the cost of a plot in the area of the cemetery that adjoins your home is $250. This makes the value of the sold-out, fully-developed lot about $100,000. If I had plans to expand that cemetery, I would not offer you more than $25K for your land, presuming that I can pack as many plots into it as possible and don't have to give up any land to extend existing roads inside the cemetery to your lot. Unless the cemetery is both sold-out and conducting regular burials, your land is worth no more than what you would get for it as a regular building lot. You want relatively flat land to use for burial plots. If it is not buildable for regular construction, it might not be that useful for burial plots. Your best cue that that the land has value to the cemetery is an offer from them to buy your land.
One thing that hurts you is that cemeteries are in consolidation, as is the death care industry. Stoneridge Partners, a real estate investment trust that is publicly traded under the symbol STON is buying something like 10 cemeteries and a few funeral parlors for a total of $10.2M. These are fully developed cemeteries. They may be worth less because many of the plots are already sold.
You might get some cash for selling the land,but wind up depressing the value of your house because a lot of people might not want to live next to a cemetery, particularly one the is right next door.