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Worm bin at Sembradores Urbanos
A box of homemade worm compost is a practical solution and ecologically appropriate to transform organic waste into natural fertilizer. This worm compost allows us to turn nutrients and organic matter into soil, to participate in natural cycles, and reduce the ecological footprint of waste we generate.
The worm box requires a minimum investment and low maintenance. It can be installed indoors and outdoors, including spaces and Departments in the city.
The worms eat residual and waste food and transforms them into a rich natural fertilizer called worm castings or vermicompost, used to improve soil structure and health.
Sembradores Urbanos is a nonprofit urban agriculture demonstration center and outreach group in Mexico City started by three women living in Mexico. There vision is to transform urban soil into green, productive, and sustainable spaces. They opened the The Center for Urban Agriculture Romita, one of the first urban agricultural community spaces in Mexico. The center demonstrates a variety of urban agriculture and organic gardening techniques as well as serving as a space for workshops and courses. This is one in a series of DIY urban gardening and sustainability projects at Sembradores Urbanos.
The worms you need are popularly known as California red worms. They are a kind of worm that live in the soil where organic matter accumulates, transforming waste into fertile soil very efficiently, and they are adapted to live in a box.
How many worms do you need
The number of worms that need extra depends on how much "food for worms" generate a week. If you start with one kilo of worms (approximately 1000 worms), they will be able to process half a kilo of waste per day.
Constructing the Worm Box
- Find a wooden or plastic box. The box should at least be 45 cm deep and have a lid to maintain a dark and humid environment. Drill at least 10 holes distributed evenly around top quarter of the box for ventilation and one hole in the bottom to collect liquid manure.
- Prepare the padding. Using a newspaper printed in black and white ink, cut 2cm wide strips. Place the strips of newspaper in a bucket of water to wet and squeeze out to remove excess moisture. Arrange the paper in the worm box, avoid compacting the padding, and fill the box 3 / 4 parts. Sprinkle a cup of black earth in the lombricaja to introduce beneficial microorganisms.
- Add the worms. When you add the worms, place them above the mulch and leave it uncovered in a bright room for at least an hour. The worms are very sensitive to light and will hide in the mulch.
- What to feed to the worms. The diet of worms may include peels and the remains of fruit and vegetables, egg shells, cereal grains, tea bags and coffee grounds. Avoid citrus food scraps, very greasy or spicy foods, and products of animal origin.
- You can feed your worms with small quantities every day or give you your share once a week. When adding food, raise the newspaper padding, add your food waste and cover fresh material with mulch. Monitor the worm box each week to see if the worms are eating all the food and adjust the feeding rate when needed.
Maintaining Worm Box
Take care and maintain your worm box. If the mulch is dry, add water and if too wet add more newspaper. Slightly aerate padding once a week and add more to the newspaper as required by the decomposition of the food scraps and soil coposition.
Harvest your worm compost
Wait until the contents of your worm box acquire a dark brown appearance and a smell of fresh fertile land (usually within 1 to 3 months). Push all of the finished worm castings to one side of the worm box, add fresh mulch to the empty space and wet then start burying food on that side. After 2 to 4 weeks, most of the worms migrate to the side with new padding, and you can harvest the vermicompost relatively free of worms. Yah!
How to Use the Worm Castings or Worm compost
Vermicompost can be used for used in germination, for ornamental plants, and to increase the fertility of edible gardens.
- for germination: 1 part humus from worms and 1 part earth
- for transplanting: mix one fist full of humus with dirt before transplanting.
- for fertilizing or mulching plants: add a top layer of 5mm of vermicompost around the plants base.
Sembradores Urbanos, "Una Miniguia para amar una Lombricaja"