Does organic fertilizer really grow plants faster than the synthetic kind? You fill six peat cups with potting soil and plant grass seed in each. Three cups receive organic fertilizer (fish emulsion). The other three receive inorganic fertilizer (Miracle-Gro). You water every other day and add fertilizer once a week.
After two weeks, the inorganic fertilizer produced taller grass. On average, the inorganic group grew 1.2 mm taller than the organic group. The prediction that organic would win turned out to be wrong.
Hypothesis
The hypothesis is that organic fertilizer will produce the fastest growth results.
Plant food comes in natural and man-made forms, and each feeds the soil differently. In a test using grass seeds, three peat cups received organic fertilizer made from fish emulsion while three others received inorganic Miracle-Gro. After two weeks of watering every other day, the inorganic group grew 1.2 mm taller on average. That result suggests man-made fertilizer breaks down into a form that grass roots can take in more quickly.
This experiment puts both types side by side. You fill six peat cups with potting soil and plant grass seed in each — three cups get organic fertilizer (fish emulsion), and three get inorganic fertilizer (Miracle-Gro). After two weeks of watering every other day, the inorganic group grew 1.2 mm taller on average. That means the prediction that organic would win turned out to be wrong.
Method & Materials
You will fill six peat cups with potting soil and grass seed, then water them every other day. Three cups will be fertilized with organic fertilizer and three with inorganic fertilizer.
You will need six peat cups, potting soil, grass seed, organic fertilizer, and inorganic fertilizer.
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The results showed that the inorganic fertilizer produced the fastest growth results, on average 1.2 mm taller than the organic fertilizer in two weeks.
Why do this project?
This science project is interesting because it shows how different types of fertilizers can affect the growth of plants.
Also Consider
Variations to consider include testing different types of organic and inorganic fertilizers, or testing the growth of different types of plants.
Full project details
Additional information and source material for this project are available below.
These videos explain the science behind this project and demonstrate key concepts used in the experiment.
Join us on a weeks-long journey through a home gardener's tomato fertilizer experiment! She has taken on the challenge of testing three different types of fertilizers - both inorganic and organic - to determine which one would work best for her precious tomato plants. The three fertilizers in question are Miracle Grow Tomato and Vegetable Fertilizer, Alaska Fish Fertilizer, and Dr. Earth's Tomato and Vegetable Fertilizer. Come along and discover which of these fertilizers came out on top in terms of value and produced the best tomato plants!
