why do plants need water to grow

The purpose of this experiment is to find out whether plants really need water to grow or whether they just need to be kept wet. What is the purpose of a plant s roots? What types of nutrients do plants need in order to survive? Why do plants need water? What happens to a plant that does not get enough water? How do plants create energy? Plants need sunlight, nutrient rich soil and water to grow. Though the quality of the water has an effect on the plant s health, there are many plants that are able to grow even when they are given water that is polluted or that has some salt content. Most plants are unable to grow out of water that is as salty as the ocean, though there are a few varieties that can. Water is not always in abundant supply, and when it comes down to making sure that people have enough to drink, sometimes plants are asked to go without. Farmers have turned to using brackish water, or water that has a low salt content, for their crops.


Understanding what types of fluids plants can use can help scientists learn more about how to meet the needs of plants as well as people in times of draught. Seeds (green bean seeds work well because they grow quickly and are hardy. )
Label the containers, Water/Control, Milk, Juice, Cola, and Sports Drink. Fill the containers with potting soil. Plant three seeds in each of the pots as directed on the back of the seed package. Measure out cup of water and give it to the plants in the Water/Control container. Measure out cup of milk and give it to the plants in the Milk container. Measure out cup of juice and give it to the plants in the Juice container. Measure out cup of cola and give it to the plants in the Cola container. Measure out cup of sports drink and give it to the plants in the Sports Drink container. Place the plants in a warm, sunny place outdoors or in a window. Repeat steps 4-8 every other day.


Record the growth of the plants on a chart such as the one below. PLANT GROWTH CHART PLANT GROWTH CHART Terms/Concepts: References: Plants are autotrophic organisms, meaning they generate a carbon energy source from inorganic components. They have adapted the capability of utilizing sunlight, water and atmospheric carbon dioxide to generate energy for cell maintenance and growth. The oxygen that we breath comes from the photosynthesis carried out by plants. Through the use of sunlight and carbon dioxide, the oxygen bound in water molecules is released into the atmosphere. During the photosynthetic process, electrons are removed from the water molecule, which is how oxygen becomes separated from the hydrogen. Plants are able to convert the heat energy from sunlight into a usable, chemical-free energy that drives the photosynthetic process. Without adequate sunlight, plants would not be able photosynthesize and no oxygen would be released into the atmosphere.


Biological activity slows as temperatures decrease. The cellular functions required for photosynthesis slow down as the air cools, thereby slowing growth. Additionally, cold air typically contains less moisture, which can result in water loss from leaf surfaces and also can cause portions of water inside of the plant to freeze. Plants require more than just a usable carbon source for maintaining their structure and increasing their growth potential. Through their root systems, they are able to obtain nutrients such as nitrogen, phosphorus, calcium and magnesium from the soil. Also, soil serves to stabilize plants and prevent them from falling over. Fertilizers are frequently applied to stimulate plant growth. Certain nutrients, such as nitrogen and phosphorus are often limited in supply, which can suppress plant growth. Therefore, fertilizers give plants an additional growth boost.

  • Views: 12

why do underwater plants have long thin leaves
why do we need to water plants
why do plants need water and sunlight
why do plants need a lot of water
why do seeds need water to start growing
why do seeds need water to germinate
why do plants need so much water