Perennial rice: Plant once, harvest again and again • Hacker News Board

Re: Perennial rice: Plant once, harvest again and again

#251

Post by BenjiWiebe » Sat, Apr 08, 2023, 2:29 PM UTC

pcrh wrote: post #246

DuckFeathers wrote: post #212

Earlier quoted context omitted.

The whole "plant based" thing is based on the simplified Wall Street model of food based on misunderstanding of nutrition. For their purposes, protein and fat are just protein and fat whether they come from meat, milk, eggs or dairy... or if they come from grass seeds. If that was the case, it would make sense that we replace ALL animal agriculture with grain farming. Grains can practically be transported and stored…

>ALL human civilizations and tribes had animal foods as a part of their diet. There is not a single tribe that survived on plants alone. FYI, India contains about 280 million vegetarians.

Don't the Indian vegetarians use milk/egg products?

Re: Perennial rice: Plant once, harvest again and again

#252

Post by xyzzyz » Sat, Apr 08, 2023, 2:57 PM UTC

Timon3 wrote: post #249

Retric wrote: post #234

Earlier quoted context omitted.

It’s climate change . If global methane from rice fields is identical in 2000, 2023, and 2050 … it has zero impact on climate change. Rice cultivation isn’t completely static, so the it’s changes in rice cultivation that result in climate change.

Rice cultivation hasn't been a factor in climate for all time, only relatively recently. The increase in methane can have an accumulating warming effect. Think about it like this - the amount of rice fields is the derivative of climate change. If you increase the amount of rice fields once and don't decrease it, climate change will slowly but surely rise, even if rice fields don't increase.

No, that’s not the case, because the methane doesn’t accumulate. If you increase the amount of rice under cultivation, the methane content in atmosphere will stabilize after around 20 years, and after that there will be no more climate change resulting from the rice fields.

Re: Perennial rice: Plant once, harvest again and again

#253

Post by xyzzyz » Sat, Apr 08, 2023, 3:08 PM UTC

littlestymaar wrote: post #243

xyzzyz wrote: post #97

Earlier quoted context omitted.

Yes, this is exactly what I say in my comment. The amount of methane in the atmosphere is directly proportional to the input rate . That’s why, as I said, in steady state , when the we keep steady the amount of rice under cultivation, the amount of methane in atmosphere is not changing over time. Can you point to which part exactly is “completely wrong”?

> Can you point to which part exactly is “completely wrong”? First you said: > Not really. These GHG emissions from rice are in steady state with the amount of CO2 and methane in the atmosphere. And then now > That’s why, as I said, in steady state, when the we keep steady the amount of rice under cultivation, the amount of methane in atmosphere is not changing over time. These two statements are contradictory. If we…

There is no contradiction between these two statements. They both say the exact same thing: if rice cultivation is in steady state, the amount of CO2 and CH4 in atmosphere due to it is constant. You next say if we change the steady state, the amount of methane in atmosphere will change, but that again is not a contradiction with what I said.

Re: Perennial rice: Plant once, harvest again and again

#254

Post by NotYourLawyer » Sat, Apr 08, 2023, 3:23 PM UTC

xyzzyz wrote: post #252

Timon3 wrote: post #249

Earlier quoted context omitted.

Rice cultivation hasn't been a factor in climate for all time, only relatively recently. The increase in methane can have an accumulating warming effect. Think about it like this - the amount of rice fields is the derivative of climate change. If you increase the amount of rice fields once and don't decrease it, climate change will slowly but surely rise, even if rice fields don't increase.

No, that’s not the case, because the methane doesn’t accumulate. If you increase the amount of rice under cultivation, the methane content in atmosphere will stabilize after around 20 years, and after that there will be no more climate change resulting from the rice fields.

Yeah, but it will stabilize at a higher level than it would otherwise have been.

Re: Perennial rice: Plant once, harvest again and again

#255

Post by Timon3 » Sat, Apr 08, 2023, 3:24 PM UTC

xyzzyz wrote: post #252

Timon3 wrote: post #249

Earlier quoted context omitted.

Rice cultivation hasn't been a factor in climate for all time, only relatively recently. The increase in methane can have an accumulating warming effect. Think about it like this - the amount of rice fields is the derivative of climate change. If you increase the amount of rice fields once and don't decrease it, climate change will slowly but surely rise, even if rice fields don't increase.

No, that’s not the case, because the methane doesn’t accumulate. If you increase the amount of rice under cultivation, the methane content in atmosphere will stabilize after around 20 years, and after that there will be no more climate change resulting from the rice fields.

I'm not saying the methane accumulates, but the additional energy in the whole earth system does. Every year with additional methane has an effect. If you have no rice fields, then rice fields for a couple of years, and then again no rice fields, you'll have increased methane levels for those years. If you compared that earth to another one without those years of increased levels, the one without would be less warm.

Remember: climate change is not a derivative, it's an integral.

Re: Perennial rice: Plant once, harvest again and again

#256

Post by xyzzyz » Sat, Apr 08, 2023, 4:06 PM UTC

Timon3 wrote: post #255

xyzzyz wrote: post #252

Earlier quoted context omitted.

No, that’s not the case, because the methane doesn’t accumulate. If you increase the amount of rice under cultivation, the methane content in atmosphere will stabilize after around 20 years, and after that there will be no more climate change resulting from the rice fields.

I'm not saying the methane accumulates, but the additional energy in the whole earth system does. Every year with additional methane has an effect. If you have no rice fields, then rice fields for a couple of years, and then again no rice fields, you'll have increased methane levels for those years. If you compared that earth to another one without those years of increased levels, the one without would be less warm.…

No, the energy doesn’t accumulate in Earth over time. Disregarding the energy of radioactive decay within Earth, the Earth is in steady state with respect to energy. All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the Sun is radiated away rather quickly.

> If you compared that earth to another one without those years of increased levels, the one without would be less warm.

No, after the methane from the fields decays to CO2, both would be the same.

Re: Perennial rice: Plant once, harvest again and again

#257

Post by hosh » Sat, Apr 08, 2023, 4:18 PM UTC

thaumasiotes wrote: post #198

hosh wrote: post #71

Earlier quoted context omitted.

According to this quote: > Perennial cultivars are strongly preferred by farmers; growing them saves 58.1% of labour and 49.2% of input costs in each regrowth cycle. In 2021, perennial rice was grown on 15,333 ha by 44,752 smallholder farmers in southern China. Seems like it makes sense to them. The increased labor in harvest is probably offset by the decrease in labor for planting.

>> In 2021, perennial rice was grown on 15,333 ha by 44,752 smallholder farmers in southern China. > Seems like it makes sense to them. ...that's not the conclusion I would have drawn. 45,000 farmers and 60 square miles are both pitifully small numbers.

They may be. But consider that this is still early days. _Where_ these land are also matter. If they are on marginal lands that are difficult to cultivate, it makes a difference there. They specifically talked about smallholders rather than commercial agriculture. Although the absolute numbers it smallholders are small, it would be interesting to see what proportion of the smallholders have adopted this.

Note that, although I am commenting on the big thread started by someone claiming that it would help sequester carbon, I personally don’t consider that the main benefit.

Re: Perennial rice: Plant once, harvest again and again

#258

Post by Timon3 » Sat, Apr 08, 2023, 4:31 PM UTC

xyzzyz wrote: post #256

Timon3 wrote: post #255

Earlier quoted context omitted.

I'm not saying the methane accumulates, but the additional energy in the whole earth system does. Every year with additional methane has an effect. If you have no rice fields, then rice fields for a couple of years, and then again no rice fields, you'll have increased methane levels for those years. If you compared that earth to another one without those years of increased levels, the one without would be less warm.…

No, the energy doesn’t accumulate in Earth over time. Disregarding the energy of radioactive decay within Earth, the Earth is in steady state with respect to energy. All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the S…

> All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the Sun is radiated away rather quickly.

This is easily disproven. The Earth does trap heat - we can measure this, it's called the Earth Energy Imbalance. This imbalance has been rising since more greenhouse gases were introduced: https://www.nasa.gov/feature/langley/joint-nasa-noaa-study-f...

The amount trapped is rising because we retain the same input longer. A fraction of the total heat is radiated away (not all of it, and not "rather quickly"). If that fraction drops more heat will be trapped.

Now you have a system with additional energy due to additional greenhouse gases. Over time the gases will reduce, but the radiation is still only a fraction of the total heat! Of course over time this will very slowly trend back towards the same temperature, but even when the gases themselves have returned to previous levels, the additional heat will take a number of years to be radiated away.

Re: Perennial rice: Plant once, harvest again and again

#259

Post by specialist » Sat, Apr 08, 2023, 4:41 PM UTC

AmericanChopper wrote: post #208

arghwhat wrote: post #144

Earlier quoted context omitted.

Yes, some land is not suitable for agriculture. No, this does mean that having cattle is a neutral usage as each cattle requires agriculture to feed for 3-4 years before they are slaughtered. Yes, cattle emissions are largely from the food. No, this is not just grass that was already there and would decompose anyway - the majority of agricultural production is to feed cattle and would not be necessary without (the ef…

> Yes, meat protein is a great source of nutrition. No, it is not magically better than equivalent vegetarian nutrition. It’s not magic, but the protein from animal sources is just scientifically better than protein from plant sources. If you want to compare the nutritional benefits of different protein sources you need to account for how bioavailable they are. Some plant sources aren’t bad, but none are as good as a…

Yup.

My SO and I reverted to omnivore for health reasons. Basically Dr Wahls' "Minding You Mitochondria" thesis. Still eat a lot of rice and beans. But now make sure to get a minimum amount of meat too.

I'm so eager for vat grown protein. But only if it has the same macronutrients as real meat.

Re: Perennial rice: Plant once, harvest again and again

#260

Post by Retric » Sat, Apr 08, 2023, 5:23 PM UTC

Timon3 wrote: post #258

xyzzyz wrote: post #256

Earlier quoted context omitted.

No, the energy doesn’t accumulate in Earth over time. Disregarding the energy of radioactive decay within Earth, the Earth is in steady state with respect to energy. All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the S…

> All energy it receives from the Sun is radiated away promptly. The greenhouse effect works by delaying this radiation. The more the radiation is delayed by, the more energy is buffered in steady state. Make no mistake though: all of the energy from the Sun is radiated away rather quickly. This is easily disproven. The Earth does trap heat - we can measure this, it's called the Earth Energy Imbalance. This imbalance…

That’s true, but we’ve been cultivating rice for thousands of years. When people talk about returning the earth to pre industrial levels that’s a world with significant rice cultivation going back long enough to account for such differences.

The global energy imbalance is simply lag before temperature’s equilibrium, when you turn up the heat in your house it takes longer to heat your fireplace than a wood door. That same effect takes longer on the scale of the earth but it’s an exponential decay. Compared to the history of rice cultivation you very quickly get to millions of a degree difference in surface temperatures. We just keep adding ever more greenhouse gasses.