Raised garden beds that use the concept of the trophic chain to create new life.  What is the trophic chain?  It's the food chain, starting with producers (creatures that make their own food) which are eaten by various levels of consumers, which are in turn eaten by apex consumers. There are different food chains, depending on the ecosystem.  Every chain ends with decomposers -- the bacteria that turn organic waste into inorganic nutrients for use by producers.  Decomposers complete the cycle of life.

Here's a video that explains this very amazing gardening idea.  Afraid of drought?  Check this out:

Now see how to make one of these beds:

Decomposers work on the logs at the bottom of the hugelkultur bed and render them into fertile components for new life.  The seeds planted in the bed are the new life (producers), creating their food from sunlight (photosynthesis) and the help of nutrients being returned to the soil by the bacteria breaking down the logs.  You and I will be consumers of these producers, taking our own positions on the trophic chain.