by Grant Hawkins, lead developer for SIMOC B2 at Over the Sun, LLC
The final step of integrating Biosphere 2 into SIMOC was building the configuration files, which specify how many of each agent to include in a simulation, their starting resource balances, etc. Our aim was to replicate the real-life Biosphere 2 experiments: Mission 1 (September 26, 1991 to September 26, 1993) and Mission 2 (March 6, 1994 to September 7, 1994).
There was a major non-linearity in Mission 1 of course, which was the extra oxygen added to the habitat, beginning on January 12, 1993, 475 days into Mission 1. Some other changes were made throughout the experiment, such as adjusting the planting areas of different crops to maximize calorie-production and CO2-sequestration. To account for this, we split Mission 1 into two configurations: Mission 1a for before the O2 was added, and Mission 1b for after O2 was added. The configuration of 1b starts with the final atmosphere and concrete carbonation of Mission 1a, and includes an O2 resupply system and modified greenhouse layout.
The feature of significance for Mission 2 was improved plant productivity. We spoke with Tilak Mahato, one of the crew member on Mission 2 usually credited with improving output, and currently a researcher of Controlled Environment Agriculture at the University of Arizona. He described several specific practices that improved output:
- Removing pests immediately. Because pest populations grow so quickly, catching and remediating an infestation early has an outsized impact.
- Taking care not spread pests, fungi or diseases via contaminated tools.
Washing diseased leaves with soap and water.
- Protect seedling growing areas from roaches and other pests.
- Pollinating plants by hand. During Mission 1, the entire corn crop had failed to produce food because there was no wind to spread pollen from the (male) tassels to the (female) silk. Other plants’ pollen had been washed away by overhead irrigation.
There was no ‘primary’ factor, according to Tilak, to which the improvements in productivity could be attributed. For this reason, we added a simple field to SIMOC, ‘Improved Crop Management’, which increases productivity of the plants by 50%, and describe the specific processes above in the SIMOC web app.
The result of these 3 configurations is encouraging so far!