Plant Life Support Experimentation Suggestions

Any of these experiments would be valuable to development of gardens and life support systems for a lunar community. Some of them are ways to add more quantitative data. Some require rather sophisticated equipment and chemical analysis techniques. All of them would be a lot of fun, and would be a valuable learning experience.

1. A control field, using natural sunlight.

   Plant two identical gardens, even to the point of sorting out the seeds from a single package into two groups, one for each garden. One garden gets the lunar light cycle, the other gets the Earth light cycle.

2. A control field, using the same lighting conditions as the lunar cycle field except following the Earth lighting cycle.

3. Several parallel fields, each on a longer light cycle.

4. Measure the growth rate of the plants in terms of the height and mass of the plants vs. time.

   To measure the mass, the experimenter would have to harvest a few plants; say once a week. Choose plants that appear to be representative of the group. Pulling up the plants and cleaning their roots to weigh them will probably kill the plants; I doubt they'd withstand the transplant shock; and if they did, the act of transplanting would change the growth history of those individual plants.

5. Measure the amount of growth above and below ground for each group.

   Does changing the light level or light cycle affect the way plants develop root systems vs. stems and leaves?

6. Measure leaf surface area for each group.

   Do lowered light levels cause plants to increase their leaf area, to gather more sunlight?

7. Use lunar simulant for soil.

8. Measure the nutrients in the soil, and keep a careful quantitative log of what is added.

9. Measure the chemical composition of the soil both before and after plant growth and harvesting. See if we can tell how much of the nutrients wound up in the plants.

10. Close the plants' environment; seal the garden in a large plastic bubble (be creative).

11. Measure the amount of water put into the system, the humidity of the atmosphere in the closed environment, the amount of water in the soil.

12. Do a complete chemical analysis of plants in each group to see if the plants' prodution of sugars and whatnot changes in different conditions.

13. Vary the mix of plants.

14. Add animals, with emphasis on the types of animals you'd want to have in a lunar base.

15. Build a simple hydroponics lab and run similar experiments.

16. Vary the light cycle by using natural sunlight for two weeks, and then only low-level flourescent light for the day cycle for two weeks.

    This simulates an alternative approach to lunar gardening: we might be able to keep the plants happy with just a little bit of light during the long lunar night. After all, Earth plants do nicely even though we often have long spells of cloudy weather.

17. Measure the amount of light vs. time.

18. Measure the amount of light at specific spectral bands vs. time.

    This might be done rather simply with filters and light meters.