David Tyler writes to say,
Samples of dust collected in Apollo 11, 12 and 17 missions have been used to grow plants. After two days, the seeds sprouted. “I can’t tell you how astonished we were” said one of the scientists involved. By day 6, all the samples were stunted – the seedlings were suffering from ionic stresses. All this work is to “inform prospects for lunar exploration”.
I am puzzled by the astonishment expressed. Seeds can sprout without soil – all that is needed is moisture. Hydroponics replaces soil by providing water with the right minerals.
There are sites on Earth where plants experience ionic stresses: notably old mine workings. However, the processes of soil development eventually make these sites more productive. On the Moon, there is the additional factors of exposure to cosmic rays and solar wind.
It seems to me that the authors would frame their research in a more holistic way if they recognised that soil is an ecosystem:
The authors are setting out to design a fertile lunar soil, but it would help them if they recognised that soils on Earth have the marks of design.
Plants grown in Apollo lunar regolith present stress-associated transcriptomes that inform prospects for lunar exploration Anna-Lisa Paul, Stephen M. Elardo & Robert Ferl Communications Biology, volume 5, Article number: 382 (12 May 2022)
Moon soil used to grow plants for first time in breakthrough test BBC News, 13 May 2022