Soil conditioning for enhancing plant growth using biochar and hydrochar under microgravity

Area of Science:

• Space agriculture
• Plant physiology
• Bioregenerative life support systems

Background:

• Space exploration necessitates sustainable food production for astronauts.
• Bioregenerative life support systems rely on plant cultivation.
• Understanding plant responses to microgravity is critical for long-duration missions.

Purpose of the Study:

• To evaluate the efficacy of biochar and hydrochar as soil conditioners for Malabar Spinach grown in simulated microgravity.
• To determine the impact of these soil amendments on plant growth, biomass, and nutrient content under different gravity conditions.

Main Methods:

• Malabar Spinach was grown for 18 days under 1g and simulated microgravity (Random Positioning Machine).
• Soil was conditioned with 3% peanut shell biochar or wood hydrochar by mass.
• Plant biomass, leaf and root growth, chlorophyll and carotenoid content, and leaf nutrient levels (K, P) were analyzed.

Main Results:

• Microgravity significantly reduced Malabar Spinach fresh biomass by up to 71%, primarily due to inhibited leaf and root growth.
• Biochar was more effective than hydrochar in mitigating microgravity-induced growth inhibition.
• In microgravity, biochar application enhanced chlorophyll a and carotenoid biosynthesis by up to 36%.
• Both biochar and hydrochar treatments increased leaf potassium and phosphorus content under microgravity.

Conclusions:

• Biochar and hydrochar show promise as soil conditioners for enhancing plant growth and development in microgravity.
• Biochar demonstrates superior efficacy in counteracting microgravity's negative effects on Malabar Spinach.
• These amendments can improve nutritional value and support sustainable agriculture in space environments.