Every fruit and vegetable scrap that we eat in the ecological house is never thrown into the garbage.  Instead, we collect the scraps in a bucket and empty the bucket into a large compost bin in the back of the house.  The compost bin we use is a simple handmade design using pallets built into a box.  Compost requires 4 things to decompose: carbon, nitrogen, oxygen, and water.  Carbon is brown, dry matter.  We use the leaves that have fallen around the house and neighborhood as the carbon for our compost bin.  Nitrogen tends to be green, wet matter.  We use the food scraps as our nitrogen intake.  Oxygen is needed to oxidize the carbon and start the decomposition process.  The holes between the pallets provide oxygen to the compost.  Every few days we turn the compost which allows for the entrance of oxygen and speeds up the process of decomposition.  Water is necessary to maintain the moistness of the compost and keep the decomposing process active.  It is important to keep a balance of all these materials so the compost is able to decompose properly.


Another thing that we occasionally add to the compost is human urine.  Human urine can increase the temperature of the compost which helps kill pathogens inside.  Despite some beliefs, human urine is sterile and consists of water and urea.  Urea is mainly a nitrogen fertilizer but also contains trace elements of phosphorous and potassium.  Too much urine can cause over-fertilization, but if you catch an occasional pee into the compost bin from our favorite resident Benny, it is perfectly okay.


Another thing we add to the compost is earthworms.  Earthworms improve the fertility of the soil and help the compost degrade faster.  Earthworms eat organic dry matter and excrete it back into the compost.  The excretion of worms, also known as worm casts, helps the compost turn into humus, or matured compost, which increases the soil fertility.  Worms burrow through the compost creating aeration in the soil speeding up the degradation process.  Regular composting can take up to a year to be ready to use for gardening.  With worms, compost can be ready within a few months.