Theoretical and practical considerations of staggered crop production in a BLSS

A functional Bioregenerative Life Support System (BLSS) will generate oxygen, remove excess carbon dioxide, purify water, and produce food on a continuous basis for long periods of operation. In order to minimize fluctuations in gas exchange, water purification, and yield that are inherent in batch systems, staggered planting and harvesting of the crop is desirable. A 418-day test of staggered production of potato cv. Norland (26-day harvest cycles) using nutrients recovered from inedible biomass was conducted at Kennedy Space Center. The results indicate that staggered production can be sustained without detrimental effects on BLSS life support functions. System yields of H2O, O2 and food were higher in staggered than batch plantings. Plants growing in staggered production or batch production on "aged" solution initiated tubers earlier, and were shorter than plants grown on "fresh" solution. This morphological response required an increase in planting density to maintain full canopy coverage. Plants grown in staggered production used available light more efficiently than the batch planting due to increased side lighting.