Analysis

The dirt for Mars Base Zero was dug from a former garden location. Samples were set aside and kept so a future, in-depth analysis could be performed. An initial, amateur analysis was performed which showed that the levels of nitrogen, potassium and phosphorous were all low. Some of these may actually be available in the soil, but tied up in the rich organics that was in the soil at the time it was added to Mars Base Zero.

The pH of the soil is a little acid, but at 6.2 just inside desirable range of 6.0-6.0.

Due to the low levels of nutrients, every second week Miracle Grow was added to the water at the rate of 1 teaspoon to a gallon of water (or about 2/3 of a cup for 30 gallons of water). This was watered on every crop that was out of the ground at the rate of one gallon per square yard (~1 meter).

Carbon dioxide was enriched for a number of months. This seemed to help fight off the aphids, though this is an impression and not a scientific observation.

Ethylene, though not measured, was detected due to the presence of curled leaves (epinasty) in indicator plants (sunflower).

Plant tissue analysis were not undertaken due to the stresses in the system posed by freezing, aphids, etc. which probably would have shown stress rather than nutrient deficiencies.