These lands are no longer used by farmers due to degradation of quality and also better economic opportunities for them elsewhere.
What are some things one can do with these lands profitably, with minimal capital investment?
From time to time some people do try to utilise ground that is right beside their own property even if it's just becomes a larger garden ... from what I see of it, a lot of the time it doesn't work out.
Unless you can buy this land cheap or rent it at a fixed rate long term five years minimum, ten is better, I think you'd be wasting your time. The #1 problem people who might do this on the hand shake of the land owner / company director(s) would run into is realisation. Realisation occurs when your efforts prove there is or look like money to be made, and attitudes shifts to where the land owner would like a bigger cut or simply insist it was only for a year or two and you should leave.
If you can secure the land via a rent agreement, then they next challenge is matching a crop with the climate ... then with the soil quality.
The usual stuff comes to mind: paintball arena, minimal restaurant, storage yard etc. but wanted to know if there's something innovative that I haven't thought of as yet.
Vacant land if you can acquire suitable agreement over three or more years could have many minimal business activities.
I've been watching someone convert a former paddock into what I'd guess is a motorbike track with jumps. They've been slowly working at it for a couple of years.
With a wide area and plenty of room it'd also be ideal for a training area for those who wanted to start learning up on getting skills to operate different machinery. Even trucks and tipping so someone can get some experience. I got a fork lift ticket when I was back from dropping out of uni, from a guy who could certify fork lift driving tickets. All he had were a couple of forklifts (may have simply borrowed them for the weekend) and offering training while having an agreement with owners of the large garage to train on the weekends, less than 20 years later, he had expanded to many other machines (coal mines are in my area,) a number of training points, a large full time successful business.
Thanks for the tip on forklift & similar training tools - super useful, has got some juices flowing.