Achieving maximum plant yield in a weightless, bioregenerative system for a space craft

Area of Science:

• Plant physiology and crop science
• Biomass production and yield optimization
• Controlled environment agriculture

Background:

• Maximum plant yield is limited by photosynthesis, respiration, and harvest index.
• Previous research faced challenges with mineral nutrition and optimizing light utilization.

Purpose of the Study:

• To investigate methods for maximizing wheat yield under controlled conditions.
• To assess the efficiency of wheat growth concerning theoretical maximums.
• To identify challenges and propose solutions for space cultivation.

Main Methods:

• Wheat cultivation under controlled light (low-pressure sodium lamps) and elevated CO2 levels (1700 ppm).
• Monitoring biomass production, achieving 97.5 g total biomass m-2 day-1.
• Evaluating life-cycle efficiency at 56% of theoretical maximum carbohydrate production.

Main Results:

• Achieved 89% of maximum theoretical growth through efficient canopy development.
• Successfully grew wheat under low-pressure sodium lamps.
• Identified mineral nutrition issues as nearly solved.

Conclusions:

• Canopy development is a key factor for increasing wheat yields.
• Current methods approach optimal growth parameters.
• Further research is needed to address engineering and plant response challenges in microgravity for space applications.