Agriculture is an important economic sector of China, employing over 300 million farmers. Beginning in about 7500 BC with classical millet agriculture, China's development of farming over the course of its history has played a key role in supporting the growth of what is now the largest population in the world.
Wet rice or paddy rice agriculture is carried out particularly in fertile areas of southern and central China where a mild climate favors two and sometimes three crops per year. The growing of rice is frequently rotated with other crops such as winter wheat, sweet potatoes, corn, and vegetables of various types. Vegetable oil producing plants — specifically rape-seed (the oil of which is known in the U.S. as canola oil), peanuts, and sesame — are widely grown throughout this region on appropriate soils.
China's economy depended traditionally on wet rice agriculture, a labor-intensive method of cultivation with uneven demands for labor input. Chinese farmers solved this problem by using their families as their labor forces. Traditional agricultural technology and population growth thus became closely related: the best chance a Chinese peasant had to improve his life was to have a large family, intensify the family effort to cultivate rice in the traditional way, then use whatever extra income the family generated to buy more land until the amount of land owned matched what the whole family, working together, could farm at maximum productivity — or even exceeded the family's capacity, an impetus to expand the family size.
In North China and Manchuria, a civilization was established about 2000 BCE and by the Zhou dynasty, 1000 BCE, there is evidence of canals and extensive irrigation. The writings of Confucius (551-470 BCE) mention 44 food plants including horticultural crops such as peach, plum, Japanese apricot (Prunus mume), jujube, chestnut, mulberry, quince, Chinese cabbage, bottle gourds, and various melons.
Collectivized agriculture was introduced in the 1950s as a means of generating agricultural surplus to support urban industrial development, but it proved not to be a satisfactory solution. Under the economic reforms inaugurated in the 1980s, farming is once again contracted to individual peasant families. While successful in raising output, the return to family farming is working against the other essential policy of population control.
In the 1st Century, Fan Sheng-chih's Agricultural Manual describes intensive production (Fig. 12-6). This includes multiple cropping, (winter wheat or barley followed by millet); pretreatment of seed (steeped in fertilizer made from cooked bones, manure, or silk worm debris, to which aconite or other plant poisons added); irrigation of rice, water trapping for dry land fields in the north; cultivation in pots and pot irrigation; ridge cultivation; scheduling of fertilization, watering and planting; organic matter recycling; soil adaptability to crops; and iron tools.
Agricultural policy has gone through three broad phases: the 1950s, when agriculture was collectivized, ending with the Great Leap Forward (1958-60); the period from 1961 to the death of Mao Zedong in 1976, when more agricultural progress came to depend on the supply of capital and modern inputs; and the period under the post-Mao leadership, which has been characterized by greater reliance on markets, prices, and incentives to boost production and to diversify output.
Although some mechanization of the process of rice production has occurred over the centuries, the production of paddy rice continues to involve the intensive use of human labor even to the degree that there sometimes is insufficient labor available for a particular activity.
Agricultural science suffered from changes in policy and emphasis after the 1950s. The Cultural Revolution disrupted agricultural science training and research programs, but since the mid-1970s training and research programs have been restored. Government officials emphasized practical, production-oriented scientific work. The rural extension system popularized new techniques and new inputs, such as sprinkler irrigation systems.
Since the late 1970s China has moved from a closed, centrally planned system to a more market-oriented one that plays a major global role - in 2010 China became the world's largest exporter. Reforms began with the phasing out of collectivized agriculture, and expanded to include the gradual liberalization of prices, fiscal decentralization, increased autonomy for state enterprises, creation of a diversified banking system, development of stock markets, rapid growth of the private sector, and opening to foreign trade and investment.
Chinese agriculture reached the highest point in its development in the eighteenth century. Its techniques, the variety of species cultivated, and its yield made it the most skilled and highly developed in history before the appearance of modern agronomy.