Martian soil and what can be grown natively.

This is awesome information and the exact type of research needed. Do you know off the top of your head if any similar studies have been done for lunar soil? If not no worries I'll do some diligence.

Brayden you were working on a Mars Soil Workshop weren't you? Can you share anything about that?

Brayden,
You present some useful data here, and well organized. However, it is really neither correct nor valid to refer to Mars regolith as soil. Calling such a material soil implies a biological process of decomposition to create it, which does not happen on Mars or on the Moon. A better term for it may be substrate for plant roots, at least initially until it is possible to enrich with surplus biomass from, say, algae , that is produced by the Controlled Ecological Life Support System (CELSS). Marc

What do you think are the obstacles for hydroponic, vertical farming using LED lighting? Would we have to ship in nutrient fluids or could some of that be made on Mars?

It seems that we have the macronutrients and some of the micronutrients needed to grow plants with a hydroponic system in the Martian regolith and atmosphere. The question is how can we extract them efficiently? I'm not a chemist or biologist, but does it make sense to say that a bacteria could be discovered/designed to do the neccessary chemisty?

Primary nutrients are nutrients that are required by plants in larger quantities than other nutrients. The primary nutrients include nitrogen (N), phosphorous (P), and potassium (K).

-from https://www.maximumyield.com/definition/2017/primary-nutrients-n-p-k

Micronutrients:

These nutrients include chlorine, molybdenum, copper, iron, manganese, zinc, and boron

-from https://www.maximumyield.com/definition/173/micronutrient

Looking at the data bellow most of these exist in some form in the regolith and nitrogen exists in the atmosphere. If most of these can be extracted then maybe we would only need small amounts of micronutrients to be shipped from earth - unless we can find them on one of Mars' moons!

Brayden,
Calling these soil alkalinities moderate is rather an overstatement. Considering the fact that Ph 7 is neutral in the exact center of the Ph scale, and normal water in nature falls between Ph 6 and Ph 8, it is not a big difference. Milk is Ph 6!

If you would please refer to my earlier comment, that we cannot call Mars regolith soil because soil implies a biological process of decomposition.

However, it would probably be possible to develop a biomass decomposition-based substrate for growing plants on Mars. To do that, we would need a Controlled Ecological Life Support System (CELSS) that produced excess biomass such as dead algae and other plant matter, and processed fecal solids and urine to produce fertilizer for the substrate.

A more difficult question concerns how to process regolith to remove constituents that might be toxic to plants or people, i.e. Life as we know it. One of these compounds of the greatest concern is perchlorate, ClO4. Also, the very high metals content, particularly Fe and Al could pose some issues.

Hydroponics have been proven for a number of crops, but it requires a steady input of nutrients. On Earth, those nutrient formulas are available commercially; making them on Mars would be much more problematic.

However, if we use the biomass excess from a bioregenerative life support system (BLSS), we can make a start on growing crops on Mars.

Although plants could probably grow in the raw Martian substrate, we should probably focus on manufacturing a true Martian soil (compliant with Marc's correctdefinition of the term). That is, we are going to want to process the native substrate, redistributing the chemical composition, and introducing a useful microbial composition. This will be supplemented through the recyclation of organic waste products, especially through controlled composting.