rice cultivation in Asia is usually described as very labor intensive, and reputedly being a Chinese peasant really sucks. Also, rice cultivation seems to have been fairly labor intensive in other places, e.g. in ante-bellum South Carolina they had to import lots of black slaves of some particular tribe that knew how to manage the paddies.
Meanwhile, rice is today grown in places notable for high labor costs, most notably in Japan and Korea and also in some places in USA (maybe labor costs a bit lower, but still nothing to sneeze about).
This makes me wonder if perhaps there are at least two ways to grow rice - the labor intensive one used in poor Asian countries and the non labor intensive one used in rich Asian countries and in the West.
Could any experts in the subject weigh in? What are the different ways this is done to achieve various levels of labor expenditure? What are the pros and cons?
Not an expert, and to bump it to the top of the list, I’ll give my semi-reasonable guess.
I’d bet it comes down to mechanization. In a poor agricultural society, many hands are available cheap, machines are expensive, have maintenance costs, and need parts. In more affluent societies, the cost of labor is higher, but maintenance & parts on machinery is more efficient.
Rice can be grown in non-flooded fields, but requires additional weed control. Flooding of fields is apparently done to not only irrigate the field, but to reduce weeds, and pests. Might flooding of fields also contribute area that would otherwise be unused, and inappropriate to other crop uses?
Some agricultural crops, however, cannot be mechanized. I don’t know from rice, but pineapple production is extremely labor intensive and cannot be mechanized.
but what is it that is especially labor intensive about rice and how is it now mechanized?
My question is inspired by the observation that people don’t describe non-mechanized cultivation of wheat by Europeans in the past as profoundly labor intensive, except during the short harvest period. And now with mechanization labor expenditure seems to become almost zero.
Well, so what is different about rice? What makes it more labor intensive without technology?
I’m not sure what your question is. Mechanized rice cultivation is cheaper and more productive than any other method, so naturally anywhere it is practical to do so rice is cultivated using mechanization.
Hand cultivation takes place in places where mechanization is either not an option, such as cash poor-labor rich environments, or where manual cultivation is used to produced a ‘premium’ brand, such as some Japanese rices.
One problem with the mechanization of rice planting is that you had to transplant the seedlings into a wet field. If you tried to do that with a planter, the machine would sink.
Technology marches on, and now there are small rice plantersthat are light enough to take into the fields.
The key difference between rice and other cereals is that rice grows in flooded fields i.e. in water 15-20cm deep which acts as thermal insulation. This is necessary as rice stops growing at temperatures less than 12C. Other cereals will die if they get flooded.
In the mechanised systems the flooded paddys are usually air seeded. The seed needs to be soaked for a day or so and then left to germinate before seeding. If you broadcast dry seed on water, a lot of it floats and gets blown/washed about giving uneven coverage, poor germination and poor production.
In the intensive systems they plant rice as seedlings. This has two significant advantages. Firstly the establishment rates are higher and the growing season shortened by a couple of weeks, which is important if you are trying to get a second crop in one season.
Interestingly enough, the highest yields per area are achieved in the mechanised systems e.g. in Australia @ 11MT/Ha
Throughout it’s production, from planting, establishment, growth, seed setting, maturation and harvesting, growing rice is all about water management