Session

2023 session 5

Location

Weber State University

Start Date

5-8-2023 11:00 AM

Description

Nitrogen (N) is needed by plants in the highest amount among root-zone-derived nutrients. Closed life-support systems for space missions will rely on in-situ food production for long-term sustainability, but high resupply and N fixation costs necessitate N recycling to support human nutrition for extended mission durations. We studied combinations of four N forms [ammonium, nitrate, urea, and N-fixing bacteria (protein)] for their use as an optimal N source for lettuce (Lactuca sativa) grown in peat moss in two container sizes (1.7 L and 8 L). Plants grown with ammonium nitrate consistently had the highest mass. When ammonium, urea, or microbial biomass were added to root-zones, hydrolysis and ammonification likely occurred, which may have led to slower growth. A larger container led to more variable growth among treatments and it was difficult to maintain even moisture throught the root-zone. Our results show that optimization of N source and growth conditions could allow for continuous N recycling in closed systems.

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May 8th, 11:00 AM

Optimizing Nitrogen Use for Continuous Recycling in Closed Life Support Systems

Weber State University

Nitrogen (N) is needed by plants in the highest amount among root-zone-derived nutrients. Closed life-support systems for space missions will rely on in-situ food production for long-term sustainability, but high resupply and N fixation costs necessitate N recycling to support human nutrition for extended mission durations. We studied combinations of four N forms [ammonium, nitrate, urea, and N-fixing bacteria (protein)] for their use as an optimal N source for lettuce (Lactuca sativa) grown in peat moss in two container sizes (1.7 L and 8 L). Plants grown with ammonium nitrate consistently had the highest mass. When ammonium, urea, or microbial biomass were added to root-zones, hydrolysis and ammonification likely occurred, which may have led to slower growth. A larger container led to more variable growth among treatments and it was difficult to maintain even moisture throught the root-zone. Our results show that optimization of N source and growth conditions could allow for continuous N recycling in closed systems.