© 1989 Milwaukee Lunar Reclamation Society - Louise Rachel, Mark Kaehny, Peter Kokh

Guidelines for Experiments on Lunar Agriculture

In your own basement or garage, you could do simple gardening experiments that will help zero in on information future lunar settlers will need to successfully grow their own food.

Background: Lunar Habitats

Long-term human settlements on the Moon are possible only if they are self-sufficient in growing their own food. However, the moon's month-long dayspan-nightspan cycle requires that plants be artificially lighted during the two-week long lunar nightspan.

Once established, habitats must import as little as possible from Earth. Their ecology must be clean and recycling; they must be shielded from dangerous solar radiation under a blanket of several feet ( a couple of meters) of dirt, the pre-pulverized powdery "regolith" or "moon dust". They will need enough sheltered cubic volume for living, working, playing, and growing crops. Yet enclosing and pressurizing habitat volume will be too expensive to allow the pioneers to indulge in excess acreage. Daytime power would come from plentiful solar electricity, but some other source of power will be needed during the 2 week long Lunar nightspans.

These facts have two implications for lunar agriculture. One is that acreage must be intensively worked and produce the greatest harvest possible per bed. The other is that providing plants enough light during the lunar nightspan to allow them to produce sufficient yield will constitute the settlers' single biggest -- and most expensive -- need for power. Success may depend on knowing accurately the least light diet that will still yield an ample harvest. These guidelines enable any interested person to help gather this critical information.

Special Needs of Lunar Agriculture

Crop harvests, in other words, must be maximized -- within the need to control lighting costs. It is vital to know exactly how much light plants will need during the nightspan just to sty alive, how much to grow at all, how much to grow with seed-to-harvest time similar to that of plants that have all the light they need. These questions can only be answered experimentally.

Many separate experiments are needed, and many of them can be performed by individuals without access to very advanced equipment. In order for such efforts to furnish useful information, everyone participating in the project must use the same guidelines.

Variables

Several variables determine the growth of plants. Each experimenter should design trials such that, in the process of testing plants' lighting needs, only one variable (usually one regarding lighting) is changed in any given trial. the main variables are:

  • candlepower / wattage / lumens per square foot
  • light spectrum (filters used?, warm or cool light, etc.)
  • amount of time in light or darkness and pattern of alternation
  • drainage / watering / moistness of the soil and air
  • air temperature
  • soil temperature
  • soil type, including phi
  • size of plot / volume of soil per plant

One thing at a time

Since the purpose of these experiments is to learn about minimum plant lighting needs, you should test either spectrum, intensity, or length of time the plants are lit. Other variables should be controlled so that they remain uniform in both test and control groups. Indicate which variables you studied and how you designed the experiment to test just that one.

We hope to recruit experimenters whose growing conditions vary (from humid Southern summers to dry Northern winters), and have therefore tried to create rules so that each experimenter can set up whatever condition seem to work, so long as only one variable is tested in each trial.

Standard practices for all

Phases in all experiments
  • Use artificial light throughout the experiment for all plants (don't put them out in the sun at any time)
  • Use automatic timers to turn lights on and off instead of relying on memory
  • Grow plants in containers such as pots or troughs
  • Alternate two weeks of simulated lunar dayspan with two weeks of simulated lunar nightspan throughout your experiment run - except for "Earth-normal" control groups, if used
  • Use 18 hours of light alternating with 6 hr. of darkness (each 24 hours day) to simulate Lunar dayspan lighting conditions (we assume that during the lunar dayspan, maximum use of relatively cheap solar power will be made)
  • Use a steady routine of 18 hour simulated daylight and 6 hours of darkness each day for the two-week simulated lunar nightspan period - continuing this pattern right through harvest
  • State at which point in the simulated lunar cycle you sowed the seed (i.e. did you sow at the beginning, middle, or end of the simulated lunar nightspan two week period?)
  • Continue your trial until harvest, plant death, or normal-light maturity time. Examine plants at normal-light maturity time for their condition and closeness to maturity.
  • Note as the key result, whether a plant produced a harvest or simply survived (or did not survive).

We ask that, whatever plants you choose to work with, you should use non-hybrid cultivars. We intentionally do not specify which plants should be chosen for experimenters, since full-blown settlements will require a great variety of food plants, plus spices, dye plants, medicinal plants, fiber plants, and possibly some fodder plants and grasses. We need data on samples in all these categories.

We do ask that you use open-pollinated / standard varieties in this set of experiments

Suggestions

lighting: "grow-lights" are not necessary. A combination of one warm-fluoresent bulb and one cool-fluorescent bulb, or even one coo-fluorescent with an incandescent bulb will usually grow the plants just fine and be much cheaper. Use the same setup controls and experimental groups in any experiment, and report what you used. One important area for experimentation is how to get the best possible spectrum for the least possible cost.

humidity, drainage, and watering: keep plants adequately mist without giving them wet feet -- whatever your particular situation requires for doing that. Again, report what you did, and keep control and experiment groups the same for this variable. Note that if one group has much more light than another, it may need more water to keep the same level of soil moisture. Report this if it happens.

soil temperature: do not heat the soil unless providing heat seems necessary for germination. Report what you did.

soil type: avoid all synthetic fertilizers and pesticides. Organic methods, including composted manures, worm castings, and compost are preferred for enriching soil. think in terms of what will be available in a closed system on the Moon, where there are no fertilizer factories and in which any chemical pesticides will be dangerous to all lifeforms present (as Biosphere II in Arizona is already proving). Remember that the settlers will live immediately downwind and downstream of themselves.

transplanting: Report it, if you do it.

Forms

We expect that different people will repeat other people's experiments and that each experiment will generate further questions for the next series of trials. To help many people in various places work together, we will provide a sample outline to follow for reporting results. We plan to send periodic news letters to all interested people. Include one dollar with your report if you wish to receive updates on this project.

Follow-up

Experiments are best done in series, with each trial pointing out what modifications are needed to fine-tune the next. Let us know when you begin each experiment and report on each one even if you consider it a failure. (Determining conditions of failure may be the most important aspect of this projects!)


Anyone conducting such an experiment, is asked to report results to us at;

Lunar Agriculture Experiment

c/o The Lunar Reclamation Society

P.O. Box 2102, Milwaukee WI, 53201

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