In response to the growing global population and subsequent need to more efficiently use fresh water resources, the objective of this study is to advance the knowledge in the field of aeroponic systems by determining the optimal droplet size for absorption of the nutrient solution to the roots of a vegetable, such as lettuce. Further, this study intends to determine how effectively the optimal conditions for one variety of vegetable can be applied to grow other vegetables. The plan for the study is to build four aeroponic chambers to simultaneously test varying droplet sizes for optimal root absorption under the same conditions to further the knowledge in this field of study. The impacts of this research will not only benefit the development of an agricultural technique that more efficiently uses available fresh water on, but also has the potential to be a sustainable technology utilized in future space exploration.
The global population has grown by 6 billion people over the last century, and is trending to approach 9.7 billion people by the year 2050. Agriculture accounts for 70% of global fresh water usage. Agricultural technologies must be developed to accommodate for the increase of food production to meet the demand of the growing global population and the resultant increase fresh water used in agriculture. Aeroponic systems, which reduce water usage by over 90%, are a promising solution to supply an increasing quantity of crops while simultaneously demanding less fresh water usage. By progressing the research in the field of aeroponic systems, crop yield and fresh water usage can be improved, which overall leads to a more efficient and environmentally friendly crop growing technique with many potential future applications.
The aeroponic system will be designed to test optimal droplet size for root absorption for a vegetable within an aeroponic system. Lettuce will be the test plant due to the relatively brief growth time from seedling to maturity of 30 to 45 days, allowing for more than one opportunity to conduct an experiment and collect data. Each of the four aeroponic chambers will be tested in an indoor, controlled environment with the same nutrient solution atomized into four different droplet sizes per test environment. The nutrient solution will be monitored with pH and electroconductivity sensors. Temperature, relative humidity, and light intensity, would be recorded above and below the surface of each aeroponic chamber. The droplet sizes per aeroponic chamber will range from 30 to 90 microns to determine optimal droplet size for root absorption. Performance metrics of the lettuce grown in the aeroponic system will be compared to a control group of soil-grown lettuce, and will be based on mass of the crop yield, plant width, length, and stem diameter, number of leaves, number of roots, root diameter, and water usage.
The indoor environment will control the lighting to supply the necessary ultraviolet light for consistent plant growth. A microcontroller will command the system, regulating the intervals at which the nutrient solution is supplied to the roots, and would communicate the real time status of the system, including sensor data from the aeroponic chambers, to an online monitoring platform to ensure continuity in the system.
The project will conclude in May 2023, after collecting data for several trials within the aeroponic system. The conclusions found in this research will further the study of aeroponics by determining the optimal droplet size for lettuce root absorption and will advance the implementation of a more efficient and sustainable methodology for using fresh water in agriculture.