Nikon do make filters and a google search will find you some. had a quick look myself and saw some 72mm ones so they are out there even though I thought they did not do them.
Some varying quality / makes here:
http://www.amazon.co.uk/gp/search?ie...sort=salesrank
Pretty soon there will be people saying the usual comments re: filters like - you don`t need many , do it in software, you really only need a CPL and neutral density filters - not grads, and why stick a piece of cheap glass in front of expensive lenses. I think the CPL filter is the most useful and use it often on landscapes. Lee are seen as the best filteres along with B&W and they cost. If you can`t run to their chages check out 7 day shop. I got mine there and it does a good job despite being cheaper!
http://www.7dayshop.com/catalog/defa...o=SEARCH&comp=
As in all things in photography you work to a budget but get the best you can afford if you are going to use them a lot, save it if you are not sure on level of use.