How do plants extract nutrients from the ground? • Hacker News Board

Re: How do plants extract nutrients from the ground?

#51

Post by jedimastert » Thu, Mar 25, 2021, 12:19 AM UTC

littlestymaar wrote: post #48

OrbitRock wrote: post #40

Earlier quoted context omitted.

I’m pretty sure the oxygen comes from CO2. Plant carbohydrates are made directly from CO2 in the Calvin Cycle. The Calvin Cycle is the source of all of the carbohydrate building blocks in the plant, and I’m pretty sure that oxygen from H2O does not enter the equation, just CO2 and some enzymes and cofactors. If so, the vast majority of the mass is from the air. (H might originate from water but its mass is pretty tri…

I stand corrected, I had somehow built-up a wrong understanding of it (looks like those high school classes are long lost). But where does all that excess oxygen go then? (the O/C ratio is 2 in C but ~1 in carbohydrates).

It gets released into the air through the leaves. It's the animal respiration cycle in reverse

Re: How do plants extract nutrients from the ground?

#52

Post by thomasfromcdnjs » Thu, Mar 25, 2021, 7:08 AM UTC

grumpy-de-sre wrote: post #35

thomasfromcdnjs wrote: post #2

I've been doing quite a lot of gardening in the past 3 years. There is a plethora of home gardeners and/or permaculture resources on the internet that generally like as much organic matter as possible. I some of that strategy as it's convenient at home to supply nutrients to plants without much work. But, I can't help but feel it's all sort of wish washy science. https://www.youtube.com/watch?v=KHZHy3_7PPE ^ I found…

As someone who's done a fair bit of indoor gardening, including hydroponics I have to vouch for the video. Oxygen in the root zone is absolutely critical. Common potting mixes are almost universal terrible. Far too much rotting organic matter. These days I do all my gardening in a 50/50% volumetric mixture of perlite and coco coir (buffered with calcium and magnesium). With a small amount of pH adjusted hydroponic nu…

Thanks for this. I'm going to do this with all my new indoor plants. I sort of gave up on em because they constantly have issues with the supplied "soil"

Re: How do plants extract nutrients from the ground?

#53

Post by thomasfromcdnjs » Thu, Mar 25, 2021, 7:10 AM UTC

virtuscience wrote: post #45

thomasfromcdnjs wrote: post #17

Earlier quoted context omitted.

Yeah, I think your absolutely correct. Gardening is actually quite hard in this regard. Everyone is always sharing tips and tricks, for different crops, different species of said crops, different climates, different soils, different hemispheres, different sides of a mountain etc I think there will be a cool database where you can filter by those factors one day but not sure we are quite there just yet.

"a cool database where you can filter by those factors" => this is one of the inspirations for Greg, the plant care community I've been helping to build after leaving Tinder. Think Waze, for plants. We're about to launch on ProductHunt and HN, if you're interested you can check us out at https://greg.help .

Awesome, will check it out!

Edit: Checked it out

Will install it and run it on my office plants.

Outside I am a dirty gardener and tend to just let things run it's course so won't help me much there.

Re: How do plants extract nutrients from the ground?

#54

Post by thomasfromcdnjs » Thu, Mar 25, 2021, 7:25 AM UTC

jedimastert wrote: post #29

This reminds me of my favorite "thought experiment" to poke at intuition: with no other information that what most people learn in elementary/middle school science (or what I would assume is taught, i.e. the water and respiration cycles), where does the majority of a tree's mass come from? First we might look at dirt, but that doesn't quite pan out; where does the mass come from, and how would it be replenished? We d…

I was just thinking about this last week, didn't get around to googling it.

I would have been wrong, mind blown lol thanks.

Re: How do plants extract nutrients from the ground?

#55

Post by senectus1 » Thu, Mar 25, 2021, 10:21 AM UTC

speexmex wrote: post #14

jspash wrote: post #13

I'm curious what HN thinks about the current trend of root washing when planting trees. From what I've read the science is still out and people tend to be split 50/50. The root washers say that by removing all media that the sapling was grown in will give the roots more "incentive" to move into the native soil and thus it will establish quicker. Whereas the anti-washers say you are slowing the establishment by washin…

Just wash half the roots?

probably not a stupid idea. might try that going forward

Re: How do plants extract nutrients from the ground?

#56

Post by littlestymaar » Thu, Mar 25, 2021, 12:16 PM UTC

jedimastert wrote: post #51

littlestymaar wrote: post #48

Earlier quoted context omitted.

I stand corrected, I had somehow built-up a wrong understanding of it (looks like those high school classes are long lost). But where does all that excess oxygen go then? (the O/C ratio is 2 in C but ~1 in carbohydrates).

It gets released into the air through the leaves. It's the animal respiration cycle in reverse

No. It was my first understanding as well, but it's not what happens. See this link from a sibling comment: http://www-plb.ucdavis.edu/courses/bis/2A/bis2A-F11/Photosyn...

Re: How do plants extract nutrients from the ground?

#57

Post by grumpy-de-sre » Thu, Mar 25, 2021, 2:07 PM UTC

thomasfromcdnjs wrote: post #52

grumpy-de-sre wrote: post #35

Earlier quoted context omitted.

As someone who's done a fair bit of indoor gardening, including hydroponics I have to vouch for the video. Oxygen in the root zone is absolutely critical. Common potting mixes are almost universal terrible. Far too much rotting organic matter. These days I do all my gardening in a 50/50% volumetric mixture of perlite and coco coir (buffered with calcium and magnesium). With a small amount of pH adjusted hydroponic nu…

Thanks for this. I'm going to do this with all my new indoor plants. I sort of gave up on em because they constantly have issues with the supplied "soil"

Just remember that coir and perlite are non-nutritious which means you have to fertigate (water with a weak fertilizer solution).

A generic one/two part hydroponic fertilizer is sufficient for house plants. There's some coco coir specific ones but I usually water with a standard hydroponic mix at something like 50-70% of the manufacturer recommended concentration and every few waterings I'll do a flush with plain water (this stops fertilizer salts from building up).

I also recommend having calmag nutrient on hand, you can use it to buffer raw coco coir: https://www.youtube.com/watch?v=OQi8AMMIyyA and deficiencies are rather common.

It sounds complicated but it's super forgiving, zero mess, zero bugs, and plants absolutely thrive it in it. Oh and coco coir comes as pressed bricks which makes it convenient to store.

Re: How do plants extract nutrients from the ground?

#58

Post by thorwasdfasdf » Thu, Mar 25, 2021, 5:34 PM UTC

sgt101 wrote: post #36

thorwasdfasdf wrote: post #27

Earlier quoted context omitted.

Charles Dowding, the father of no dig gardening, suggests, you don't need to dig in any compost or ogranic matter, just put it on top, as you've suggested. Apparently, the worms and the microorganisms then get to work and bring all that organic matter into the ground themselves working it into a nice tilth.

Worms! If there are many worms the soil is good. If there are no worms, the soil is bad. Worms like the organic matter and convert it into tiny weeny particles that the plants (bacteria) can absorb, they also open up the soil and create structure so it drains nicely. Worms!

I'd love to have worms!!!

they say you have to build up an entire ecosystem of life in your soil to attract the most worms.

I'm trying to find more ways of attracting them but it's hard to get specific studies that show things in a quantifiable way from the gardening community. Some say leaves on the surface attract worms, some say it's composted things, some say it's compost that hasn't completely been broken down yet. But, I have yet to see studies that show precisely the percentage of worms increased by various types of organic matter. What's the optimal approach? other than just adding more organic matter.

i'm adding as much organic matter on top as I can from a variety of sources. but, it'd be great to get some actual specifics on what's most effective.

Re: How do plants extract nutrients from the ground?

#59

Post by sgt101 » Fri, Mar 26, 2021, 11:10 AM UTC

thorwasdfasdf wrote: post #58

sgt101 wrote: post #36

Earlier quoted context omitted.

Worms! If there are many worms the soil is good. If there are no worms, the soil is bad. Worms like the organic matter and convert it into tiny weeny particles that the plants (bacteria) can absorb, they also open up the soil and create structure so it drains nicely. Worms!

I'd love to have worms!!! they say you have to build up an entire ecosystem of life in your soil to attract the most worms. I'm trying to find more ways of attracting them but it's hard to get specific studies that show things in a quantifiable way from the gardening community. Some say leaves on the surface attract worms, some say it's composted things, some say it's compost that hasn't completely been broken down y…

The most effective thing for me was to find an organic matter supply that has worms. If it has worms, it will have worm eggs.

An extra thing that helped was to take some of the worm organic matter (it was a trailer full of well rotted donkey manure) and stir it into my compost heaps. My compost heaps then also got infected with worms.