Evaporation and Transpiration: What’s Your Function?
Taking the weight measurement of a plant growing in a glass jar using hydroponics.Copyright 2020 Liping Wang, University of Wyoming
What’s the difference between two common agricultural methods? What are the roles engineers play in designing better methods? In this activity, students measure and calculate evapotranspiration rates--the amount of water lost from evaporation and transpiration in a growing media (such as a pot or jar) and plant surfaces-- for living plants using soil and hydroponics. By recording changes in plant weight, students calculate evapotranspiration rates and determine which of the two growing methods is best for their design.
Hydroponics is a commonly used method for growing plants that does not use soil and is resource efficient. Hydroponic growing methods have been widely adopted for urban agriculture, such as vertical farming, within a controlled environment. Engineers concerned with sustainable methods for growing food and reducing water usage work to develop new techniques to further advance this field of sustainable urban farming. Agricultural engineers help to make farming sustainable, safe, and environmentally friendly. By analyzing agricultural operations and looking at new technologies and ways of doing things to improve land use, increase yields, and conserve resources, agricultural engineering combines mechanical, civil, electrical, and chemical engineering principles with agricultural principles.
After this activity, students should be able to:
- Explain the two different plant growth methods (soil vs. hydroponics)
- Explain the positive and negative considerations of hydroponics.
- Compare evapotranspiration for plants growing in soil and with hydroponics.