One of the food growing techniques popularised by permaculture practitioners is the so called, banana circle.
It’s a simple idea that begins with picking a sensible location. It is usually one within easy frequent reach. There must be water supply, quite often gray water or overflows. A pit is dug at such a location, in the shape of a bowl. The size depends on the scale of the project but seldom smaller than a mere deep and 2 m diameter. The excavated soil is piled around the pit in a mound. The pit is filled with all sorts of waste: anything that will biodegrade: weeds, kitchen waste, paper even. Some manure is added to start bacterial action.
A variety of plants are located on the mound around the pit. Banana, papaya, sweet potato or anything else that can be thought of as suitable. Plants mutually support one another, shielding against wind, keeping cool, filtering sunlight and acting as trellises. Beans and tomato for example can use taller plants to climb on. What we have is a mini food forest with good diversity that is well watered and fertilized and virtually maintenance free.
The name is a misnomer because neither is banana a mandatory or only plant, nor do plants have to be placed in a circle. The first banana circle at pointReturn is on a slight slope and is fed with waste water we use to wash up pots and pans after cooking. Pending the completion of a formal bathroom, we also have our baths near here; soapy water will flow into the pit, but that’s okay, since at pointReturn only cottage made vegetable oil based soaps are allowed- no chemical detergents.
In the top picture you can see the pit and excavated soil piled in a semi circular mound. In the bottom picture, you can see shredded newspaper thrown into the pit. There is a collection of weeds nearby that will go over the layer of paper. Once the system is functioning one brings over all manner of biowaste and tips it in without any care for layers or order. The pit is s processing den teeming with micro animals digesting waste and making compost continually.
Also in the picture is Chellamma, busy powdering lumps of chicken manure that we procured from a local poultry. This will be scattered on the pile to start biological activity. By the way, this Banana Circle is the creation of Chellamma and Annamalai, with stage whispers from me.
A Banana Circle is a simple carefree productive system which simultaneously processes waste. Here is one of the best articles I found on the subject: Link