(Keep in mind while reading this that I am bordering on the libertarian - it may shine through here and there.)
Norwegian farming (including dairy/milk products) is tightly regulated and subsidized, basically a necessity if one is to farm here at all - after all, (slight exaggeration) mountains everywhere and winter half the year does not lend itself well to farming.
Result being that most all vegetables, meats and dairy products are purchased from farmers by cooperatives; the prices are set by the authorities as part of negotiations with the farmers' association annually. These cooperatives then sell the produce on to retailers and industry, ensuring a steady income to farmers.
This model wouldn't work if the same products could be freely imported from countries more suited (less mountains, less winter!) to farming - so we impose heavy tariffs on most products from abroad - with exemptions for produce from some of the least developed countries.
For instance, lamb is taxed at 429% on the goods value to make import prices comparable to the cost of producing it in Norway. Same goes for a number of dairy products - we have import quotas on, say, cheese - and if imports are too large in a given year, heavy tariffs are imposed to limit it.
The upside to this policy is that it is possible to make a living from farming even in the subarctic regions; it can be argued (IMHO, rightly so, even if it clashes with my libertarian credentials!) that farming is beneficial to local communities - unless the pastures are tended to, the part of the country which is not barren mountain would be covered in shrubs in no time at all.
The downside, obviously, being that food is much more expensive than it needs be; this issue is countered to a large extent by our petroleum-boosted economy, ensuring that even at the artificially inflated prices, food is comparatively cheap in Norway. Also, as the tariffs are not imposed only on basic foodstuffs, it ensures that specialities which already fetch a premium in global markets - think pata negra etc. - are outrageously expensive here.
In broader terms, one of our major challenges in the decades to come is that we've tended to solve - nah, make that postpone - any problem by throwing petrodollars at it; as oil production decreases, we've got some pretty tough choices ahead as income slows while expenses skyrocket.
For instance, we've relied on a pay-as-you-go pensions system; as people tend to live longer (and we've, to an extent (exaggeration again) kept unemployment numbers artificially low by providing disability benefits to the long-term unemployed), this is not sustainable (same situation as in a number of developed countries).
Now, pensions is to an extent cushioned by our close-to-a-trillion USD petroleum fund, but then there's all sorts of other obligations - say, tax-funded healthcare, (very) generous sick leave terms &c.
So - we'll need to axe our expenses, but in our very consensus-driven political system, no politician would dare step forward and actually DO something - after all, that would see his or hers chances of reelection plummet. You don't win elections by promising people that they will get less paid in retirement or when ill.
Oops. I just noticed that you said 'unrelated to the problem of funding welfare.' My bad.
A number of sectors face issues similar to that of the publishing industry - it is a small market, and with Norwegian hardly being a world language (All told, some 5 million native speakers), anything involving the Norwegian language sooner or later becomes an effort to prop it up - so publishing is not seen just as publishing; it is an effort to keep Norwegian alive and well. This has led to legislation which - believe it or not - makes it illegal to sell newly published books at a discount; this is to ensure that publishers get a decent return on translating and publishing books in Norwegian, but leads to such absurd situations like me wishing to buy the latest Jo Nesbo thriller as an eBook would cost me more than buying it on dead trees (as a 25% sales tax is imposed on eBooks, while paper books are exempt), but buying the same book on my Kindle or on paper via Amazon, translated into English, can be done at (typically) less than 20% of the over-the-counter Norwegian price.
Again, I can see where the advocates of such policies are coming from, but it does mean that we have a number of sectors of our economy which needs to be protected from the world at large through quotas and taxes. Now, obviously, everyone thinks their own sector is special and needs this kind of protection, whereas all others are just freeloading whiners who make everything more expensive than it needs to be for the rest of us.
Rant over. (I'll try to compose something a bit more articulate if some of the above piqued your interest. :)