Natural fertilizer with stones

Marco Antonio Umaña Aguilar
CCIAL/El Salvador

Participants make natural stone compost or stone dust by crushing small and medium-sized stones with a hammer or mallet to strengthen soil used for planting or potting. This avoids the use of chemicals that are dangerous for the environment.

  • Stones of different sizes, shape, color, texture, to crush.

For each participant you need:

  • A hammer or mallet for each participant.
  • Several fine strainers, they can be homemade or a fine mesh.
  • Glasses for each participant to protect the eyes.
  • Plastic or newspaper.
  • Small bags for the mixture.
  1. Look for small to medium sized rocks near the activity area.
  2. Before starting the activity, look at each of the stones that you collected, look at its shape, size, touch its texture, experience its smell, if possible try it if it has any flavor.
  3. Everyone should put on glasses to protect their eyes.
  4. With the hammer, crush the stones on the plastic or newspaper until they are the size of grit or flour.
  5. There is an older person to supervise or if you need help request it.
  6. When finished, collect all the content that everyone managed to get out, then sift it in the strainer.
  7. Put the sifted compost in a bag to take home.

At the end of the tour, let’s clean up the site where they worked!

  • Beforehand, check if the area where they will do the activity is free of objects that could harm the participants, such as: insects, sharp fallen branches, etc.
  • Choose an area where there are many stones and is spacious to work without danger of hitting yourself.
  • You should have enough plastic bags on hand to fit the stone flour.
  • If the group is very large, divide them into small groups with an assistant to lead and supervise them in each group.
  • Teach them the handling of the hammer or mallet, also the necessary precautions to avoid damage, give some safety rules: do not grab the stone while hitting it with the hammer, the use of glasses, keep the necessary distance.
  • If it is possible to request extra materials from each participant in advance, do so. (hammer, lenses, strainer, plastic bag, etc.) Otherwise you have them on hand.
  • After having the mixture, place it in a plastic bag so that each participant can take it home.

Note: This activity could also be carried out in planned stages of several days to achieve greater benefit in the preparation of stone fertilizer and obtain greater production at the end.

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