Rice production in China

Wild rice and its domestication China is among the bulk of significant domestication centres and originating rice regions worldwide. The surrounding regions of the Yangtze River and the Yunnan-Guizhou highland of Southern China are the domestication centres with varying evidence derived from the belief that wild rice is primarily found in Southern China, where the Yangtze River is predominantly situated. China's Yunnan-Guizhou highland consists of more than 10,000 rice landraces, and the three wild rice species (O. Rufipogon, O. Officinalis, and O. Mereriana) commonly exist and is identified as the site of the highest genetic diversity. The oldest sample collected comprised a median age of 11,000 years, found upon clustering in the middle of the Yangtze River in the provinces of Hubei and Hunan in central China. == Rice variants ==

Wild rice There are three species of wild rice in China, O. mereriana, O. officinalis, and O. rufipogon. The last is the most common, spanning from Taiwan and across China. Wild rice is commonly found in marshlands, hills, and low grasslands. Archaeological records note common variants of wild rice were planted in Central and Southern China in antiquity. Due to increased human activity over the years, there has been a 70% decrease of O. rufipogon across China compared to the 1950s. Chinese cultivated varieties Cultivated varieties are noted to have originated in areas near the Yangtze and Huai rivers. From these areas, wild, ancient varieties spread through environmental and cropping conditions. Over time, these varieties evolved and were domesticated into O. sativa subspecies japonica and indica. ==Rice breeding==

Hybrid rice breeding seeks to improve yield and adaptation in response to demand and environmental challenges and was introduced in the 1970s by Yuan Longping. == Subspecies by region ==

Japonica Japonica plants are small and have dark green leaves. Its grains are round and short and do not break easily. Due to its high levels of amylopectin, the grains are moist and sticky when cooked. Japonica is found in cool and temperate climates. Indica Indica plants are tall and have light green leaves. Its grains can range from short to long, narrow and flat, and can break easily. Due to its lower levels of amylopectin, the grains are flakier and drier than japonica variants. Subspecies and their growing regions • Japonica subspecies are predominant throughout Regions 2, 3, 5, and 6. • Indica subspecies are predominant throughout Regions 1, 2, 3, and 4 • Hybrid variants of Indica are grown in Region 2. == Geographical setting ==

Growing regions Region 1: Southern China This region includes southern areas of Guizhou, Guangdong, Guangxi, and Fujian and Hainan provinces, as well as Taiwan. This region is subtropical and predominantly grows indica rice. == Production ==

Processes Cropping systems Cropping systems vary across China due to differences in climate in each growing region. Single rice cropping is predominant in the North, accounting for 17% of the country's total rice production. Double rice cropping is mainly utilised in the South, accounting for 34% of the country's production rate. Annual rice-upland crop rotation systems are commonly used in Central regions such as Hubei, Sichuan, Anhui, and Jiangsu provinces, as well as near the Yangtze River Valley. Rice-upland systems generate 49% of the nation's rice production. Planting methods Planting methods depend on the environmental and socioeconomic conditions of a growing region. Common methods of planting include manual, throwing, mechanical, direct seeding (manual and mechanic), and ratooning rice. Manual transplanting is declining in rural areas due to lack of skilled labour. It is common in areas with smaller land areas, high populations, and higher rates of available labour. Direct-seeded rice (dry and wet seeding) has increased since the 1990s, taking up 10% of China's rice planting area in provinces such as Guangdong and Xinjiang. Transplanting is where rice seedlings grown in a nursery are harvested and transplanted into puddled and levelled rice fields 15 to 20 days after the seedling, some even for an extended incubation period. These rice seedlings can either be transplanted manually or mechanically. Manual transplanting is a traditional rice production method across China. Manual transplantation does not require costly machinery and is often performed in minor rice patch fields in labour surplus. Manual transplanting is often performed in rice patch fields with substandard levelling and varying water levels. Both mechanical transplantation and direct seeding of rice are pioneering rice planting methods and are commonly used during the rice-wheat rotation system. The convenience of direct seeding and mechanical transplanting method can be manifested in the rice planting area of the Jiangsu Province in China, which comprises 2.249 million hectares of land, encapsulating 55.9% of fields that use these methods interchangeably. and has been predominantly used over the past few decades in Southern China to raise yields, as was tested by scientists in Southern China rice patches along the Yangtze River. The method of the experiment is through an "appropriate increase in seedling density, and a concomitant decrease in Nitrogen fertiliser input" that led to "problems with lodging, quality declines, and environmental pollution". – this makes rice ratooning a favourable practice for production. From the former, rice ratooning is acquiring new crops from renewed tillers of the first crop, saving water consumption by taking advantage of the remaining water content from the first crop. From the latter, rice ratooning increases farmers' profitability with sustainable efficiency and fewer reconstruction efforts on environmental damage and footprints than other rice planting methods. Quality There are differences and changes in the selection of rice varieties and cultivation techniques under various planting methods. Therefore, selecting good-quality rice is "necessary to promote the development of high-quality rice industry and enhance the rice industry's comprehensive strength in China." Therefore, the formation of rice quality stems from a range of aftermath processing factors and not only from the inherent characteristics of the different varieties of rice grains. Rice filled under high temperatures increase chalkiness, which is considered an undesirable feature due to the adverse effects on the rice's appearance and milling quality. Moreover, researchers in the China National Rice Research Institute conducted studies in rice fields and have found that an increase in potassium fertiliser used to improve root growth, plant vigour, lodging prevention, and enhance crop resistance to pests could reduce the chalkiness and improves rice quality, but have adverse effects on human consumption. Changes to planting areas There have been dramatic increases and decreases in arable land and production across China. Increases were found in Northeast provinces such as Jilin and Heilongjiang, whilst increasingly urbanised provinces such as Guangdong and Fujian saw decreases. This is due to more farmers and their families looking for a stable occupation in urban areas, as well as challenges to production due to climate change and lower grain production due to over-usage of fertilisers and pesticides. == Exports ==

In 2019, China exported 4.56% of the world's rice with a value of US$1.13 billion. In 2020/2021, it was the sixth principal rice exporter in the world behind India, Vietnam, Thailand, Pakistan, and the United States. In the period of November 2020 and November 2021, China's Rice exports accounted for up to $75 million and imports that accounted for up to $202 million. It was a year that particularly resulted in a negative trade balance of $127 million. In November 2021, rice mainly exported to Turkey accounted for $11.1 million, South Korea, for $9.54 million, Vietnam, for $7.49 million, Cameroon for $7.39 million, and Puerto Rico, making up $7.1M. Imports were mainly from Thailand of $44.4 million, Vietnam for $40.9 million, Pakistan for $34 million, India for $31.5 million, and Myanmar for $30 million. == Challenges ==

Climate change Rice is a prominent primary food staple for most of the world's population, and it is not limited to just China, despite its prominence. Rice production in China has grown increasingly during the past few decades, that is mainly due to increased yields of grain than to the increased planting areas across China, and demand for rice is predicted to increase by approximately 20% by 2030. Even so, because of rice yield stagnation that agronomists and scientists have observed during recent years, there have been limits in the capability to increase rice yields with the expectation that this is to continue into the near future. The challenge that has been causing this stagnation has been "attributed to reaching the biological yield ceiling for rice in which many studies have reported that climate change affects rice production". Climate change and its significant impacts on rice production in China present challenges in meeting China's future rice production requirements. Climate change and its impact on rice-wheat crop production and water resources are significant factors that rice production in China will have to address with the rise of climate change and resource scarcity. It is addressed by the agronomists and experts in the field of agriculture in China that as climate changes arise, the daily mean temperatures for rice of all kinds – including that of early rice (produced from March to July), late rice (produced during June to October), and single rice crops (produced during May to October) - are impacted. Overuse of fertilisers The overuse of fertilisers in agricultural rice production in China is commonly used among risk-averse farmers. Fertilisers are often overused in order to avoid the impacts that are presented by the rise of climate change and risks that are present on wheat and rice production in China. Other factors that contribute to the farmers' overuse of fertilisers is similar to that of the overuse of pesticides where farmers have limited background knowledge behind the overuse of fertilisers, along with a lack of agricultural labour force and with the traditional prospects, experiences, and habits of the farmers themselves. China consumes 30% of the world's nitrogen fertilisers, with 7% of this is employed for Chinese rice crops. Despite its excessive use, China's yield rates are comparably lower than other rice-growing nations who also utilise nitrogen fertilisers. Low amounts of fertiliser, around 20-30%, is absorbed by a plant, whilst the remaining amount pollutes surrounding ecosystems, leading to soil infertility. The overuse of fertilisers and pesticides interchangeably are what the researchers and scientists in the agriculture field of rice production in China have recognised as "inefficient and excessive". Chinese rice farmers are known to spray their crops on a weekly basis to avoid damage by pests and diseases. The overuse of pesticides in rice production in China and the driving factor for farmers to overuse pesticides in agricultural production is the "imperative to increase farmer's income, promote agricultural transformation, and agricultural sustainable development". == Future development ==

Germaplasms and genetic diversity The creation of elite germaplasms such as the indica-japonica hybrid has encouraged the research and development of new variants through studying elite genes and hybrid options. This, alongside the established super rice breeding program, has led researchers to aim to produce high quality rice which is tolerant to drought and grain infertility. Integrated cultivation systems Further developments have been made with the assistance of agriculture systems and databases to manage fertilisation, irrigation, field management, disease and pest management, as well as predictions to estimate rice yields. Water usage Aerobic rice utilises low rates of water due to its ability to grow in high altitudes. Studies are investigating its high tolerance to drought and low irrigation, in order to develop variants for rice fields in Northern and Central China with inadequate irrigation. == Consumption ==

Due to the abundance of rice grown within China, it is considered as a staple food for two-thirds of the nation. Over 149 million metric tons were consumed in 2020/2021, with an average of 76.8 kilograms milled per person annually. However, there has been a pattern of decline in rice consumption, from 78 kilograms per person annually in 1995 to 76.3 kilograms in 2009. Produced rice grains can have numerous flavours, textures, and grains, each differentiating one from another with distinct qualities. Each rice grain's distinct qualities correspond to the grain's length, stickiness once cooked, the aroma, the texture, and the flavour. This difference comes from the different grain terrains or regions used for rice production in China. Processed rice grains are rich in nutrients, vitamins, and healthy minerals, which is known as "an excellent source of complex carbohydrates". Glutinous Rice and milled rice delicacies Once cooked, a popular and common form of rice can be made into glutinous rice, which can be made into either sweet desserts or savoury dishes. Glutinous rice is also known as sticky rice. It is sweet, has a waxy grain texture, and is an opaque grain with low amylose content, which creates a sticky texture when cooked. It is a type of rice that is mainly grown in the regions of Southeast and East Asia, and it is also included in both japonica and indica types of rice. This means that the glutinous rice grains can be short, medium, or long – essentially, it comes in all sizes. Glutinous rice can be consumed by fermenting it to make rice wine. Also, it can be made into Jiuniang - fermented sweet rice serving as a critical ingredient and flavour for many famous Chinese dishes as a supplement or as a sugar alternative. Milled rice can be ground and processed into rice noodles, dumplings such as Tangyuan, Zongzi, and Yuanxiao, glutinous rice cakes such as Niangao, Maqiu, puddings, crackers, bread, and fermented food. Ground rice can range in colour when made out of red, purple, and brown types of rice. ==References==