higher CO2 means nutrient dilution in plants

[TheVat]

https://knowablemagazine.org/article/food-environment/2023/climate-change-effect-on-plant-nutrients

Atmospheric carbon dioxide is at its highest in human history. That’s probably fine for plants like the grasses the hoppers munch. They can turn that atmospheric carbon into carbohydrates and build more plant — in fact, plant biologists once thought all that extra carbon dioxide would simply mean better crop yields. But experiments in crops exposed to high carbon dioxide levels indicate that many food plants contain less of other nutrients than under carbon dioxide concentrations of the past. Several studies find that plants’ levels of nitrogen, for example, have fallen, indicating lower plant protein content. And some studies suggest that plants may also be deficient in phosphorus and other trace elements.

The idea that plants grown in today’s carbon dioxide-rich era will contain less of certain other elements — a concept Kaspari categorizes as nutrient dilution — has been well-studied in crop plants. Nutrient dilution in natural ecosystems is less-studied, but scientists have observed it happening in several places, from the woods of Europe to the kelp forests off Southern California. Now researchers like Kaspari are starting to examine the knock-on effects — to see whether herbivores that eat those plants, such as grasshoppers and grazing mammals, are affected....

[mistermack]

7 hours ago, TheVat said:

in fact, plant biologists once thought all that extra carbon dioxide would simply mean better crop yields.

It can mean that. Many commercial greenhouse growers release CO2 in their greenhouses to increase productivity. 

It can also mean that some plants can survive in dryer areas. Plants have pores that they have to open to absorb the required amount of CO2 for growth. But open pores mean more evaporation, a loss that's necessary for the plant to get the required amount of CO2.

If the CO2 levels are higher, they can open the pores less, and thus lose less water. It's been reported around the world that some marginal lands are getting greener as a result.

[Sensei]

12 hours ago, TheVat said:

But experiments in crops exposed to high carbon dioxide levels indicate that many food plants contain less of other nutrients than under carbon dioxide concentrations of the past.

In nature, the faster plants grow, the more the soil is depleted of nutrients (which have not changed/increased accordingly to CO₂ levels)..

In agriculture, to prevent resource depletion ( https://en.wikipedia.org/wiki/Slash-and-burn ) man first invented crop rotation: the two-field system, then the three-field system, then the four-field rotations.

https://en.wikipedia.org/wiki/Crop_rotation

https://en.wikipedia.org/wiki/Three-field_system

Letting cows, pigs, chickens eat directly from the field is good for it because they poop and pee on it, giving up nutrients back..

 

ps. The next level is hydroponics in skyscrapers.. where you can control the amount of water and nutrients, temperature, pressure, have an environment free of parasites and pests.. unused nutrients and water are reused (not wasted as in current agriculture)

12 hours ago, TheVat said:

plant biologists once thought all that extra carbon dioxide would simply mean better crop yields.

..they could simply ask any farmer from the 20th century..

 

Edited April 25, 2023 by Sensei

[ambertcarrero]

You can also use your green house to store fermenting food buckets. the yeast makes c02 that flowrs out of your fetmentation air lock. you can also theoreticly rig exhaust fumes from say a maintain gas generator into your green house.

[guidoLamoto]

an old thread, but-- the OP may want to familiarize himself with this site http://co2science.org/

Plants grown under higher [co2] show more vegetative growth (ie- more llignin & cellulose) that "dilutes," so to speak, the amount of N fixed. They still fix more N . Yields of seeds/fruits also are higher, although there is some data that show there is some dilution of nutrients therein, over-all production of nutrients per ac is still  increased....Mistermack's response above is excellent.

While [co2] may be the highest in human history, keep in mind that H.sapiens evolved initially during the last Ice Age when [co2] levels were dangerously close to the 180ppm level that would stop all photosynthesis and essentially wipe out almost all life on Earth (chemotrophes excepted)....We are returning to pre-glaciation levels of temps & co2 (maybe- we may be headed for the next glaciation even now)...What is "normal" temp & co2 for planet Earth?