At the beginning of the experiment we mixed organic matter, green grass from another experiment (for the purists Lolium perenne L.), into the Martian and lunar soil simulants, for the bacteria. This lead to greater availability of nutrients for the vegetables. But it does more, much more.
Joep cutting the grass into small pieces after which it is mixed with the simulants.
At the beginning of the experiment we mixed organic matter, green grass from another experiment (for the purists Lolium perenne L.), into the Martian and lunar soil simulants, for the bacteria. This lead to greater availability of nutrients for the vegetables. But it does more, much more.
Nutrients
The simulants contain nutrients that the plants can use for their growth. However, the amount is very limited, especially for nitrate, which is essential for plant growth. This can change by mixing organic matter into the soils, in our case grass. The organic material can supply the necessary nutrients. But that doesn’t happen easily. This is where bacteria come into play, at least bacteria that are able to break down organic material, or mineralize. If there were no bacteria, no organic material would be broken down in such a way that it becomes available again for other plants. On both Mars and Earth, organic material would pile up until there was only organic material left. Without bacteria there is no decomposition and therefore ultimately no life! However, it is unknown what exactly they do and whether they are important for the vast majority of bacteria in the soil. Some can cause diseases and thus reduce plant growth or even kill the plant. Taking bacteria to Mars won’t be that difficult, but only taking the good ones with us is the big challenge.
The grass after a few weeks is now brown, which indicates that degradation processes are taking place on lunar soil simulant.
Fungi
Can bacteria manage it alone? Probably, but fungi might help. These can also break down organic matter. Perhaps even more importantly, they can form a symbiosis together with the plant roots and thus enormously increase the nutrient absorption of plants. This collaboration greatly increases the root surface area, allowing the plants to absorb many more nutrients and allow them to grow faster. The plant in turn supplies nutrients to the fungus. Everybody happy. There is another species I would like to take with me to Mars: the worm. This comes at the beginning of the breakdown of organic material, it eats it, extracts what it can use and excretes the rest in smaller parts. This allows the bacteria and fungi to work more efficiently. The matter is pre-digested and the surface area of the organic matter increases. So let’s bring those worms, although they don’t have to be as big as in the movie ‘Dune’.