from the will-they-also-send-lots-of-bees-for-polination? dept.
Clover growth in Mars-like soils boosted by bacterial symbiosis:
As Earth's population grows, researchers are studying the possibility of farming Martian soils, or "regolith." However, regolith is lacking in some essential plant nutrients, including certain nitrogen-containing molecules that plants require to live. Therefore, agriculture on Mars will require strategies to increase the amount of these nitrogen compounds in regolith.
[...] To explore a possible role for symbiotic nitrogen-fixing bacteria in astroagriculture, the researchers grew clover in man-made regolith that closely matches that of Mars. They inoculated some of the plants with the microbe Sinorhizobium meliloti, which is commonly found in clover root nodules on Earth.
[...] The researchers found that the inoculated clover experienced 75% more root and shoot growth compared to the uninoculated clover.
[...] These findings suggest the possibility that symbiosis between plants and nitrogen-fixing bacteria could aid agriculture on Mars. Future research could continue to explore such relationships with other crops and address issues with plant toxicity in regolith.
Journal Reference:
Franklin Harris, John Dobbs, David Atkins, et al. Soil fertility interactions with Sinorhizobium-legume symbiosis in a simulated Martian regolith; effects on nitrogen content and plant health, PLOS ONE (DOI: 10.1371/journal.pone.0257053)
(Score: -1, Offtopic) by Anonymous Coward on Thursday September 30 2021, @06:44AM
#Freearistarchus!!! Remove the mod-ban!
(Score: 1) by shrewdsheep on Thursday September 30 2021, @07:49AM (11 children)
TLDR; I am wondering where the Nitrogen would come from on Mars? If it has to be supplied that could happen in a fixed form to begin with, obviating the need for symbiosis.
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @10:08AM (1 child)
We're not going to be growing anything in Martian soil until it's been seeded with bacteria for a century or two and started releasing enough CO2 to get a bit of an atmosphere. Whether or not that's possible without an active core and magnetic field, who knows?
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @12:11PM
Just use a wormhole to pipe pollution to Mars from Earth. It's so simple. The biggest problem is finding a Marsworm. I can supply the Earthworm.
Just throw a few weed plants thru and everyone will want to go to Mars!
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @11:41AM (2 children)
How about the atmosphere?
(Score: 3, Funny) by Rosco P. Coltrane on Thursday September 30 2021, @12:18PM (1 child)
I think his question was more "Which atmosphere would the nitrogen come from". Because surely plant life or Earth origin requires more substantial an atmospheric density than the nun's fart spread out over an entire planet that is currently on Mars.
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @01:13PM
Just grow everything indoors. Take soil, water, and nitrogen from outdoors as needed.
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @12:15PM (1 child)
Didn't you see The Martian?
Matt Damon's excrement.
(Score: 2) by maxwell demon on Friday October 01 2021, @09:34AM
You surely mean Mark Watney's excrement.
I doubt they actually used the actor's excrement in the movie.
The Tao of math: The numbers you can count are not the real numbers.
(Score: 5, Informative) by ElizabethGreene on Thursday September 30 2021, @03:20PM (3 children)
It's a good question.
We can gather Nitrogen from Mars atmosphere with pressure swing adsorption tech similar to what's used for oxygen concentrators here on Earth. That nitrogen will be used as an inert gas to pressurize greenhouses, but initially we can't use it directly for fertilizers. The lack of decomposers means we can't bury plant matter or poop and expect it to break down as fertilizer. It also makes legumes (nitrogen-fixing plants) problematic. The lack of nitrifying bacteria in soil means we can't use Ammonia or Nitrites either. For the initial plants we grow on Mars we'll have to import Nitrogen from Earth, specifically as fertilizers that have a nitrate ion that can be taken up and used by plants. Raw Martian regolith is only usable as a hydroponic growth medium for the first few crops, and that only after leaching it to remove perchlorates. I envision this initial system setup as a run-to-waste direct watering or drip irrigation system with the drainage seeping to a collection area with more regolith mixed with compost from Earth as an inoculant. We'll discard material and add more regolith into this "waste" to grow the population of decomposers and nitrifying bacteria. This material will become actual soil that does the complex things that soil does here on Earth. The low light, pressure. and temperatures on Mars plus biosecurity concerns means all of the growth will have to be in pressurized Nitrogen/Oxygen/CO2 greenhouses with supplemental lighting.
Once you've made real soil on Mars then things get a lot easier. You can feed part of your nitrogen stream you can feed through the Haber process to make an in situ plant nitrogen source and as a feedstock for other industrial chemistry.
You can play with this tech at home. (Links with * are amazon affiliate links. The link title contains enough information if you don't want to click through.) MarsGarden's Mars soil simulant [themartiangarden.com] for the substrate and * Masterblend 4-18-38+Calcium Nitrate+Magnesium Sulfate [amzn.to] for the nutrient solution. If I were packing for Mars I'd also pack super fast growing plants to prove out that the substrate isn't toxic like * Wisconsin fast plants [amzn.to]. On Mars I'd run these through spectroscopy to make sure they hadn't picked up any unknown unknown heavy metal contamination. If they had, then we'd switch to non-regolith deep water or NFT hydroponics so you didn't starve until you figured out how to fix the metals problem. They are also edible, if unpalatable.
(Score: 1) by khallow on Friday October 01 2021, @06:41PM (2 children)
Poop comes with built-in decomposers. And if you don't like that, just bring a clod of Earth earth. It's self-replicating.
(Score: 2) by ElizabethGreene on Saturday October 02 2021, @04:47AM (1 child)
It is self replicating, given sufficient time, food sources, and hospitable conditions. The bring-your-own solution is just for getting over the initial hump while that colonization occurs, and so we don't have to draw straws for who to have for dinner if we get bit by an unknown unknown. We'll probably have to take enough food to cover everyone fully until the next resupply window, but at hundreds of kilos per person year its problematic to go much beyond that. On a mission with no viable abort scenario (a one-way trip), agriculture is one of the things that has to work.
(Score: 0) by Anonymous Coward on Sunday October 03 2021, @05:14PM
Makes it more hilarious that so many talk about human missions to Mars but there haven't been many experiments done on whether Mars gravity is good enough for humans...
(Score: 0) by Anonymous Coward on Thursday September 30 2021, @12:35PM (3 children)
With 'As earth's population grows'
Shipping wheat from Mars simply is not going to happen.
As others have pointed out, no matter how bad climate change affects Earth, it will still be easier to grow plants on Earth than on Mars.
(Score: 3, Insightful) by DannyB on Thursday September 30 2021, @02:58PM (2 children)
Research justification:
Improving agriculture on uninhabitable planets like Mars can lead to improvements in agriculture as Earth becomes increasingly uninhabitable.
The lower I set my standards the more accomplishments I have.
(Score: 2, Insightful) by khallow on Friday October 01 2021, @06:44PM (1 child)
(Score: 2) by ElizabethGreene on Saturday October 02 2021, @04:50AM
You've hit on the big ones. To add one more, carbon capture technology is much more important on a planet where its the dominant component of the atmosphere.