Hydroponics are the most efficient growing systems around for any vegetables varieties, and a large amount of vegetables can be grown in a small space, and when hydroponics are matched to a glass house environment you can just about grow crops year round in most countries.
Hydroponics as good as they are are not ideal for all situations on a self sufficient property, some systems are complicated and expensive to set up, the cost may be justified on a large scale commercial growing operation for selling produce to super markets and the public but maybe not for a small self sufficient family farm.
There are six hydroponic methods or systems available, the simplest and most cost effective is Water culture, the plants are held in a water solution that contains all the nutrients the plant needs to grow and air pumps circulate the water this setup is ideal for lettuce plants and this is the only plant that will grow with this system.
The Wick System, the plants are held in a medium with wicks drawing the nutrient rich solution up from a water tank located under the plants. The Ebb and flow system, nutrients are pumped into a tray left to soak then pumped out again this goes on in a cycle until the plants are grown.
The Drip System, water jets are located over the plants and a pump sprays the nutrients over the plants at regular intervals and drains into a tank to complete the cycle. The NFT system, this system is the most common the nutrient solution is pumped in at the top of the tray which sits at an angle the flow is constant and is recovered at the end of the tray to be recycled back into the system.
The Aeroponic System, this system works by suspending the plants in the air and a mist of nutrient solution is sprayed up under neath the plant and into the root system a timer controls the spray so the roots are always moist.There are home made hydroponic systems used all over the world with a bit of planning you can make your own, but they do require electricity to run the pumps which may not be beneficial for off the grid living.