Building your Column:
1. Assembling your column: Using a pair of scissors, cut the top off the plastic bottle so that it looks like a cup. Invert the cut piece into the cut bottle to form a funnel.
2. Collecting soil: With a large bucket and spade, collect 2-3 kilograms (4-5 pounds) of soil from an area of your choice. It can be a garden, a riverbed, or any area that is convenient.
3. Filling your column: Use your spade to fill the cut bottle through the “funnel”, ensuring to leave one to two inches near the top free.
4. Remove the funnel, discard/recycle, and cover the mouth of the cut bottle with cellophane wrap.
5. Place a rubber band around the wrap to hold it in place. Puncture two small holes, opposite each other and close to the rim of the bottle using the scissors.
6. Wait! It can take up to three weeks for microbial colonies to form. If you live in a cold place, it can take even longer. Be patient. Colonies will show up as white, yellow, or differently colored patches. They may be fuzzy, smooth, or jagged. Make sure your column gets two to three hours of sunlight every day.
Now that you have your column, you can experiment with it! Scientific experiments always need to have a control. In a control, nothing is altered. This way, you can compare it to a situation when you change something and see the effect! A Winogradsky column made as above would be your control. To experiment on it, you can:
1) add an egg, which is a source of sulfur.
2) add a sheet of shredded newspaper, which is a source of carbon.
3) expose the column to different levels of sunlight by changing how long you leave it in the sun.
Remember that whatever you do, you always need to have a control to compare your experiment to! Notice what microbes might change, whether any new colonies appear near your newspaper or egg, and see which level of sunlight has the most colonies and which appear first.