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Comment by twawaaay | Hacker News Reader

I am not convinced (I grew up on a farm).

It is usually harder to get rid of any weeds when your crop is growing on the field. After harvest, you just get rid of everything, turn the soil (but I don't know anything about rice farming) and you kinda get a fresh start.

ON THE OTHER HAND, we already have robots that can easily identify weeds with a camera and zap them with lasers or other shit. Which just seems so much more reasonable in the near future than trying to harvest individual rice grains off of a perennial plant that cannot be damaged so that the plant can provide sun cover to prevent weeds... just not seeing it.

Also, Chinese harvests rice up to three times a year. And the harvest itself is much easier if you can grab entire plants. So I am not convinced anybody is going to get interested in it.

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I am a farmer.

It is quite close to impossible for weeds to establish once many crops reach a certain stage, this is pretty consistent with the perennial idea.

Stripper headers are quote commonly used all over the world:

https://youtu.be/nppu5OfjisQ?t=90

The assertion that a perennial plant "cannot be damaged" is also incorrect, many perennial crops benefit agronomically from a "trim", even non-perennials have economic circumstances where it makes sense to "damage" the crop, e.g. grazing winter crops in the late fall.

https://extension.okstate.edu/fact-sheets/dual-purpose-wheat...).

Permaculturist here.

With the exception of trees, most plants that establish after their taller peers do not try to dominate the canopy. They have already lost that fight. Instead they either stay low and work with the limited light available, or they aggressively grow in the spring to complete their entire lifecycle before the deciduous canopy closes at the beginning of summer. They might steal a little fertilizer, and some water, but the jury is still out on whether some plants conserve as much water as they use. It's a fuzzy enough area that you can find people who claim that some plants increase total available water.

We are just beginning to fully appreciate all of the ways trees have to ladder up from the forest floor to the canopy, and some of the things we perceive as competition may be a misunderstanding.

Thanks for info, neat!

Most problem weeds on the prairies where I farm are taller than the planted crops when mature, particularly as yield benefits have been gained by shortening more and more varieties over time. A pigweed or a smartweed will outrun a wheat crop with a week of head-start like nothing. Corn can't take any competition at all, I had a planter row in my Barley of corn one year, I figured the corn would simply outgrow the barley and leave it in its proverbial dust.. quite the opposite, I sprayed the Barley out at about the 4-leaf stage and the corn was a full 2 feet shorter than the row beside it at maturity!

That all said of course a natural prairie is different, the tall-grass prairie - as far as I understand it - competes for water under the ground more than light above it - shade can actually help! (Lord knows I mow under my trampoline twice as often as the rest of the lawn.)

This is also true in nature. Weeds (or think invasives in an ecological) tend to be plants that do best in disturbed contexts like fires, landslides, after logging, or in the agricultural sense, tilled soil. Invasives tend to struggle to gain a foothold in established healthy ecosystems

With typical rice farming in Asia, you see manual transplanting of each seedling in to small fields by women and children. This is back-breaking work and extremely slow. I can't think of another crop both this widely cultivated and painstaking. Therefore, not having to do this is a huge win.

China has a multitude of climatic areas. Some harvest rice once per year, others two or three times per year. Even within Yunnan, the province in which tests are being made, all such areas exist.

Many rice farms are small scale and on inaccessible land at the bottom of river valleys, terraced up hillsides, or otherwise inaccessible locations which would provide substantial scale-related and physical challenges to ease of automation. Try running an automated robot over this topography: https://upload.wikimedia.org/wikipedia/commons/7/70/Terrace_...

Rice planting machines exist, doesn’t look much different from home lawnmowers. IIRC, in spring farmers make a batch of rice sprouts on disposable cups, load them into this, and it lays them down as the old man drives across his field back and forth.

0: https://youtube.com/watch?v=uS54w2ZH-OE

Anywhere that is rich enough uses these rice planting machines. You see them frequently in Japan, Korea, Taiwan, etc.

I believe "flat" rather than "rich" is more of the limitation. Machines cost almost nothing in China, but the access or field topography very often makes them untenable.

    Machines cost almost nothing in China

Are you talking about the machines that can mechanize the planting of rice seedlings? I find it hard to believe that poor farmers in China can afford these machines, unless this state is providing for free, or with zero interest loans and very long repayment periods.

Also, most rice farming in China isn't done on difficult topography. I call that stereotype the "National Geographic" effect. If you look where most rice farming is done, it isn't very steep or mountainous. See more here: https://www.statista.com/statistics/242360/production-of-ric...

China makes almost all of the world's EVs, the world's motors and the world's wheels. Putting together any kind of agricultural vehicle is cheaper in China than elsewhere. That's just how it is. How do I know this? I just returned from seven years making robots in China. I will stop short of looking them up and pricing them, but feel free to do so.

AFAIK the Agricultural Bank of China is the largest bank in the world by some measures. It almost certainly has the most branches, and these are overwhelmingly located in agricultural towns and villages. Recall also, in communism sharing equipment is normal. People don't all need to buy their own. Chinese villagers like villagers elsewhere help one another.

Yes, flat areas exist. But they are not the test area, Yunnan. And if you were to look at the historical spread of rice farming (a subject of considerable academic debate) you would notice that all academic suggestions of the earliest invention of rice agriculture itself, with very few exceptions, appear to disperse through or via the test area, because it is the natural headwaters of rivers feeding the majority of mainland East, Southeast and (very close by) South Asia, including the Yangtse, the Pearl River, the Red River, the Mekong, the Salween, the Irrawaddy, and the Brahmaputra. Given we know that in ancient times river valleys formed natural communications paths this give us a fair case for the general dispersion of rice farming technology specifically through steep terrain areas and specifically through the test area.

It might be dated information, but I'd heard 3 crops per year going back at least as far as 1900 (Farmers of Forty Centuries), but not that it was three rice crops per year. Instead a rotation of different crops in the same field.

One of the tricks with rice is you can germinate it in one field, then transplant it to something like 4-6 times the same space to grow to maturity.

It's absolutely three rice crops per year in some areas. The transplanting strategy is the normal one.

Hot and wet, like some areas of Thailand can support three rice crops per year.

What about the people practicing permaculture and regenerative agriculture? There's been a big movement there to perennialize crops, and there are well-known patterns and practices from there to work with perennials.

It seems they are not gently collecting the individual grains of rice.

http://en.people.cn/n3/2021/1025/c90000-9911067.html

You should see how they harvest lavender. If I were an anthropomorphic plant I'd probably loose my lunch after seeing one of those videos.

This is my impression of why we can get away with this. Annuals tend to gamble with weather conditions. There's enough seed bank stored up from previous years that if a scouring windstorm breaks all of the stalks in an area, then the seed bank can help recover next year, and if that's not enough then some seeds will blow in from the edges eventually, and ten years from now you can't tell.

Perennial plants have to be sturdier. Only some, such as alpine species, are adapted to drop damaged limbs. They are used to being jostled by hail, storms, and herd animals, so the insult is less permanent.

I don't know how that translates to perennial grasses, except that most such grasses can and sometimes do burn to the ground, and regrow each year from rhizomes. Half the plant survives each growing season, and the other half is sacrificial.

Industrial farming of the sort you describe is destroying arable land, and relying on petrochemicals and strip mines to keep marginal land on life support. Properly managing the land using a mix of perennial crops and occasional rotation to pasture restores the soil, builds fertility, and requires very little in the way of inputs. Healthy plants in a polyculture setup where niches have been pre-filled also resist weed invasion better than monocultures.

We do a lot of stupid shit in farming for the sole reason that farm machinery is specialized, and proper land management costs more (in the short run, in the long run the land is much more productive).

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