COMPLETED VERSION Worm Farm Writeup

 

Worm farm ecosystem

Apparatus	• 500 ml Beaker	• 2 × 2 Litre Soft Drink Bottles	• Scrap Vegetables (Not Fruit)
• Measuring Device	• Commercial Worm Farm Bedding	• Shredded Newspaper	• Compost Earthworms
• Scissors	• Spray Bottle Of Water	• Drawing Compass	• Blender Or Chopping Board And Knife

Recorded Mass of Worm Farm Across 3.5 weeks

	Total Mass	Mass of Waste Material	Total
Day 1	1295	0	1295
Day 5	1295	0	1295
Day 6	1288	0	1288
Day 8	1286	0	1286
Day 13	1283	0	1283
Day 15	1281	0	1281
Day 19	1279	0	1279
Day 20	1279	0	1279
Day 22	1277	0	1277
Day 26	1276	0	1276

The mass of the beaker was: 353 to 354 grams. The worm farm itself weighed 830 g. The vegetable scraps had a mass of 111 g. Slight differences of around a gram were recorded.

The observations made during this experiment include:

·        No waste material ever touched the beaker- the newspaper shredding absorbed or blocked it.

·        During the first few days, condensation occurred at the top of the bottle.

·        The vegetables dried up and sprouts grew from the beetroot. Smaller worms appeared, and small insects began to fly in and around the container.

Conclusion/Results

Did the inputs (food and water) equal the outputs (wastes)? If not, why not? The wastes would never have equalled the inputs due to the time limit (4 weeks) and small spaces through which water vapour and other gases would have been able to escape from. Sealing up the container would ensure that nothing escapes from the container. Some of the food will have been broken down by bacteria/fungi.

How does the mass of the worm farm at the beginning compare with the mass at the end of the 4 weeks? How can you explain your results? A total of 7 grams were lost in the first week. After this, the mass decreased slowly to end at 1276 grams. The rapid decrease in the beginning would have been due to the escape of water vapour. Since sunlight was not allowed to fall on the farm, the process of photosynthesis would not have been possible.

Respiration chemical formula: C₆H₁₂O₆+O₂→C0₂+H₂O+ENERGYcan be used to signify how earthworms breathe. Without external factors acting or addingonto the farm, respiration will decrease the total mass of the farm. The food and newspaper weight would have decreased and become carbon dioxide and water, which can then escape from the container. The energy produced would have been used up by the heat and activity of the worms. There was no input and only output for this farm.

As worms break down food they produce faeces called castings. This forms a rich garden soil. How do you know this process was taking place in your farm? The growing sprouts may indicate this. We shall have to open up the container and empty its contents in order to find the worm castings. To check whether this process took place, we could also extract the food at the top and observe the difference between it and the food before. This can be made possible with photographs.

If your worm farm was kept in the dark, where did the energy to keep it going come from? The food scraps and nutrients in the soil were enough to keep it going. Sunlight was not required due to the inexistence of plants. Earthworms cannot stand prolonged exposure to sunlight or any light.

Explain how your worm farm is a living ecosystem: The food placed on top provides the energy for the activity of worms. The water sprinkled on top is enough for the worms to survive on. This provided enough for the worms to survive and reproduce during the 3.5 weeks of observation. However, I think that this worm farm may not be a ‘living ecosystem’, as we used this term to describe a container (terrarium) with plants and sunlight last year.There was no photosynthesis occurring this year. Despite this, earthworms have been known from the past to be vital or important to agriculture. Therefore, this farm we have created can be thought to be a balanced and living ecosystem. Except, the only input possible is the food (due to the container) and water (rain) which we have to add to the container. Widespread usage occurred in New Zealand. Many birds and bugs rely on earthworms for their food supply. The food may not have been small enough. Faster breaking down of the food would have allowed some waste material to break through the newspaper bedding and land in the beaker. In the wider world, earthworms play a very important role in forests. They are one of the first to eat the fallen leaves. A rich soil is created for other plants to live on. Their tunnels allow air to travel through (better drainage). The microorganisms deep inside the soil will be re-energized and break things down more quickly. A stable soil structure will be built. Research on earthworm ecology has not been very widespread. The soil we had was made up of sand, dirt, air, and water. Small animals and microorganisms live on the castings. This increases the diversity of the soil ecosystem. The cycle that takes place in the soil is very often forgotten or ignored. There are also worms that exist in aquatic environments.  By Noah Nishihara Home Group T09