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Agricultural Ideas for Science Fair Projects

Agriculture doesn't have its own category in science fairs, but it is a part of many of the "official" categories. Here, we've put together a few basic ideas of agricultural science projects you can do. Use these ideas as a jumping-off place for coming up with your own project.


How do different conditions affect the speed at which fruit and vegetables ripen?

Temperature, light, placement in sealed bags, exposure to other ripe fruit--all have different effects on different fruits. You'll need to look into ethylene gas.

How do different types of fertilizers affect plant growth?

Fertilizers differ in their amounts of the nutrients nitrogen, phosphorus and potassium. Get different fertilizers from a garden shop or nursery and apply them to groups of the same plant. Do the different fertilizers change how the plants grow? You could measure height, width, number of leaves, how fast the plants grow, number of flowers or yield.

What happens when you grow sweet potatoes next to other plants?

Compare how fast the other plants grow at different distances from sweet potatoes. Remember to grow some control plants nowhere near the sweet potato. Check out the term allelopathy.


How do different treatments change how fast seeds sprout?

You can find out how quickly seeds sprout under different temperatures, or after being soaked for different times or in different liquids. Or, see how one kind of treatment affects different types of seeds.

How close does a pesticide have to be to protect a plant?

Grow a number of groups of the same plant. Apply a Bt-based insecticide directly to the plant according to the directions on the package and at various distances from the plants. Compare the amount of insect damage to each group of plants. You might also look at how big or fast each group of plants grows.

What effect does seed size have on how well a crop like oats or wheat grows?

You can define success a number of ways: how many seeds sprout, how fast the plants grow, how tall the plants get.

Environmental Sciences

How does soil pH affect the pH of water that touches the soil?

A pH meter can be found at almost any garden shop or nursery.

Gather different types of soil. Put some of each type in a cup and check out the pH. Then add water to the cups, and mix. Wait for the soil to settle and measure the pH of the water. Be sure you use water from the same source for each soil. Find out more about soil.

Does soil type change how well crops grow?

Fill boxes with different types of soils and plant the same crop in all the boxes. What happens to the plants? You could measure height, width, number of leaves, how fast the plants grow, number of flowers, or yield of seeds or fruits.

How are different soil types affected by water running over them?

Farmers in many parts of the country have to irrigate--to water their crops rather than rely only on the rain. But water running over soil can cause it to wear away, or erode. A simple experiment in soil erosion .

Medicine and Health (Nutrition)

Do different varieties of the same fruit have the same level of vitamin C?

What about different brands of orange juice? Or fresh juice compared to juice from frozen concentrate? Does the way a fruit is stored or how long it is stored change the level of vitamin C? Here's how to test for vitamin C content.

Are there different amounts of iron in different breakfast cereals?

The iron in ready-to-eat breakfast cereals is in the form called elemental, not in combination with any other chemical compound. Iron is sprayed on the outside of cereal flakes. You can separate the iron with a strong magnet.


It's easy to think of all microorganisms as bad things, as germs. But many microorganisms are very helpful, especially for agriculture, and some are even essential. Microorganisms are used to fight pest insects, diseases and weeds that make producing crops and raising livestock less efficient. Other microorganisms help make nutrients in the soil more available to plants.

What happens to the way plants grow if there are no microorganisms in the soil?

Take a sample of fertile soil from a field or garden and divide it into two portions. Bake one in an oven (to destroy the microorganisms). Leave the other portion alone as a control. Plant the same number of seeds in each soil sample. Remember to treat both samples the same while the plants are growing. Make sure all the plants receive the same amounts of water and light, and are kept at the same temperature. How do the plants differ as they grow?

Are different plants affected in different ways by specific microorganisms?

Some microorganisms and plants form mutually beneficial partnerships. For example, certain bacteria make a natural nitrogen fertilizer for plants in the family called legumes. Peas, alfalfa and soybeans are legumes. The nitrogen-fixing bacteria are available from garden supply stores and by mail order. Grow both legumes and non-legume plants with and without the bacteria. Are there differences in how well the plants grow?


Most schools have special rules about doing any experiments that involve live animals. Be sure and check with your teacher before you decide on such an experiment.

More agriculture science project ideas:

Experiments for the classroom from the ARS U.S. Water Conservation Laboratory

Ways to boss a plant around from the ARS Coastal Plains Soil, Water, and Plant Research Center

Planet Ag from the Florida Department of Agriculture and Consumer Services

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