If you are not familiar with the terms extensive and intensive, they can be a bit misleading. Extensive doesn’t mean large, it means requiring little or no additional inputs (fertilizer, compost, labor, etc.) and intensive doesn’t mean working hard, it means using a lot of those same inputs. A great primer on the differences can be found here.
For my initial garden set up, it was intensive. I purchased the raised beds, the materials to make soil (compost, vermiculite and peat moss) and seeds. But once it is set up, I was able to become much more extensive. I save seeds, any part of the plants that do not end up on a dinner plate go into the compost to feed the next generation, seedlings that need to be thinned have those same two options – food or compost, or as my son says “the circle of life”.
I still have water as a major input when the skies aren’t doing the watering for me and I still have to buy some seed, but otherwise it is a pretty closed cycle with most of what my garden needs coming from my garden and yard. I have looked into the rain barrel collection options but I am not convinced that water that has run off a petroleum based shingle roof is a good idea for growing my food.
In the meantime, more and more people like me, who have a generational disconnect from the conventional farming ways of our grandparents and great-grandparents are taking up farming and urban farming. With this new generation of growers we are seeing an entirely new set of best practices and innovative ideas. Maybe someday soon I will be able to have a completely closed system.