Rice growers and millers have constantly sought to innovate technology as a way of growing better rice. To tell the history of rice cultivation is also to tell the history of its evolutions. Of the many technologies bundled into rice cultivation, two of the most important are the shifts in engineering that have shaped how irrigation takes place and how rice fields are constructed and used. A consistent and secure water supply is key for rice-growing. From the 5th-6th centuries, local water reservoirs were constructed all over the proto-nation of Japan, and literally shaped its landscape. At the same time, large irrigation channels were constructed to transport the water. In the early sixteenth century, when the ruling daimyo were engaged in a series of clashes and power grabs, these aristocratic leaders poured resources into rice production.
Under their orders, fields were built on land that was prone to flooding and protected through improvements in flood control technology. In the eighteenth century as civil engineering became more refined, terraced paddies were constructed from land on the sides of Japan's many mountainous slopes. The landscape of terraced rice fields whose contours are often described in terms of lyrical beauty can still be seen to this day in mountainous regions of the country.
New strains of rice have been key to refining the high quality of Japanese rice. The first phase of breeding technologies took place in the nineteenth century, at the same time as advances in civil engineering took off. The major effect of the trial-end-error methods that growers used was to increase crop yields. Then in the nineteenth century, the major effect was to breed varieties of rice that could withstand the harsh climate and diseases that were particular to the northern part of the island and Honshū as well as Hokkaidō---the regions that are known today as the primary rice-producing regions of the country. Growers want to produce good rice, no matter the location or era. They have a strong conviction that Japan is the "home" of rice, and that the commitment to quality that underpins Japanese rice owes much to the wisdom and cleverness of Japanese know-how.
Advances in tools have also contributed to the quality of Japanese rice. For instance, an excavation in Shizuoka prefecture called the Toro ruins has unearthed a wealth of wooden tools used about 1700 years ago. These included implements like hoes and plows used to till the land, wooden geta shoes for tromping around in the fields, and small flat-bottomed boats used in rice planting. These implements suggest how Japanese farmers have used tools in skillful and innovative ways since the time that rice-paddy cultivation became mainstream in Japan.
Around the fifth or sixth century, farmers began to plow their fields with oxen and to use livestock, as well as use tools like hoes and plows now made of steel, not wood. These shifts had a positive effect on the productivity of rice growing.
At the turn of the seventeenth century, kind of threshing rake, the "thousand-tooth rake," was invented and completely revolutionized agricultural work. It enabled threshing to be done more easily that it was done manually, and its use became widespread. In the twentieth century, a threshing machine that was operated by stepping on a pedal that caused the rotation of a large spiky drum that stripped off the grains. This machine was used until the Second World War.
Japanese agriculture became thoroughly mechanized after the war, during the period of high-speed economic growth after 1955. As in many industries after about 1960, many kinds of division of labor took effect along with new higher levels of technology, and Japan became the first in the world yo launch a combine for specific use in rice cultivation. In this evolution, a single machine became able to both cut the stalks of rice in the field and thresh them, or pull the individual grains from the stalk.
As we enter the twenty-first century, the commitment to improving quality in Japanese rice continues unabated. This includes improving the quality of rice itself as well as striving for cultivation that follows environmentally sustainable practices. For instance, there are farmers who use aigamo ducks to control pests in their rice fields. This works to reduce dependence on chemical pesticides because the ducks are a natural predator of certain insects, and moreover, they eat other kinds of grass while being uninterested in eating rice. There are other farmers who leave water standing in the fields after harvest, when they traditionally would have drained the fields, so that migratory birds like geese, swans and cranes can pass the winter in the fields. By collecting these kinds of local solutions and wisdom beginning agricultural land management, farmers are aiming at an agriculture that can co-exist alongside nature. The continued commitment to quality in producing Japanese rice means a commitment to improvement that goes beyond rice itself.