abstract
The accumulated temperature of rice refers to the effective temperature for rice growth. Rice is a short-day crop that likes temperature and humidity. The main ecological factors affecting rice distribution and zoning are heat, water, sunshine, altitude and soil.
Impact factor (IF)
① Heat resources. Generally, the place with accumulated temperature ≥10℃ and 2000-4500℃ is suitable for planting one-season rice, the place with accumulated temperature of 4500-7000℃ is suitable for planting double-season rice, 5300℃ is the safe limit of double-season rice, and the place above 7000℃ can plant three-season rice.
2 moisture. The influence on rice layout is reflected in the principle of "determining rice by water";
③ sunshine hours. Affect the distribution and productivity of rice varieties;
④ The change of altitude affects the distribution of rice through the change of temperature;
⑤ Good paddy soil should have high water and fertilizer retention capacity, and also have certain permeability, and its pH value is close to neutral.
divide
The rice-growing areas in China can be divided into 6 rice-growing areas and 16 sub-areas.
Ⅰ. Double cropping rice planting areas in southern China. Located in the south of Nanling, the southernmost part of China, including the southern part of Fujian, Guangdong, Guangxi and Yunnan, Taiwan Province Province, Hainan Province and the South China Sea Islands, there are 194 counties (cities) (excluding Taiwan Province Province for the time being). The rice area accounts for 17.6% of the whole country.
Ⅰ 1. Double cropping rice subregion in hilly area of Guitai Plain in Fujian and Guangdong. Changle County and Taiwan Province Province in Fujian Province in the east, Guangnan County in Yunnan Province in the west and Wuchuan City in Guangdong Province in the south, including 13 1 county (city). The accumulated temperature is 6500-8000℃, and the annual temperature is ≥ 10℃. Most places have no obvious winter characteristics. The sunshine hours in rice growing period are 1200. Precipitation 1000-2000mm, and the safe growth period of indica rice (the interval from the start of daily average temperature 10℃ to the end of 22℃, the same below) is 2 12-253 days; Japonica rice (the interval from the beginning of daily average temperature ≥ 10℃ to the end of ≥20℃, the same below) lasts for 235-273 days. Paddy fields are mainly distributed in river plains and hilly valleys, which are suitable for the growth of double cropping rice. Double-cropping rice accounts for about 94% of the annual rice area. Double cropping rice is the main crop in paddy field, and indica rice is the main variety. The main pests and diseases are to choose varieties with stress resistance, high quality and high yield; Advocate returning rice straw to the field after abdomen and increase the application amount of potassium fertilizer; Develop winter bean, vegetable crops and double cropping rice rotation system.
Ⅰ2. Single-season rice subregion in the valley basin of southern Yunnan. The northern boundary starts from Malipo County in the east and passes through Maguan to Yingjiang County, including 465,438+0 counties (cities) in southern Yunnan. The terrain is complex and the climate is diverse. The southernmost low-heat valley is close to the tropical climate. The annual accumulated temperature is ≥ 65,438+00℃, and the sunshine hours in the growing season are 65,438+0,000-. The precipitation is 700- 1600 mm, and the safe growth period of indica rice 180 days or more, and japonica rice is more than 235 days. Paddy fields are mainly distributed in river valleys, and the upper limit of planting height is 1800-2400 meters above sea level. In most places, only one season of rice is planted every year. Bacterial blight and Chilo suppressalis are the main pests. In the future, it is necessary
Ⅰ3. Multiple cropping subregion of double cropping rice in Qionglai Plain. Including Hainan Province and Leizhou Peninsula, there are 22 counties (cities). The annual accumulated temperature is ≥ 10℃, and the rice growing period is 8000-9300℃, 300 days in the south and 365 days in the south. Three crops of rice can be planted in a year. Growing season sunshine 1400- 1800. Japonica rice lasted for more than 273 days. Typhoon has the greatest impact and the land productivity is low. Double-cropping rice accounts for 68% of paddy field area, mostly triple cropping system, mainly indica rice. The main pests and diseases are rice blast, yellow rice borer and so on. In the future, it is necessary to improve water and fertilizer conditions, increase multiple cropping, expand winter planting, and give full play to the potential of increasing production.
Ⅱ. Central China Double Cropping Rice Planting Area. It starts from the coast of the East China Sea in the east, reaches the western edge of Chengdu Plain in the west, connects Nanling in the south and Qinling and Huaihe River in the north, including all or most of the eight provinces (cities) of Jiangsu, Shanghai, Zhejiang, Anhui, Jiangxi, Hunan, Hubei and Sichuan, as well as the southern parts of Shaanxi and Henan provinces, and is the largest rice planting area in China, accounting for 67% of the national rice area.
Ⅱ 1. Double cropping rice subregion in the middle and lower reaches of the Yangtze River. It is located in 235 counties (cities) in Jiangsu, Zhejiang, Anhui, Shanghai, Hunan, Hubei and Henan, north of the isoline with an annual temperature of ≥5300℃, south of the Huaihe River, and from the mountainous area in western Hubei to the east coast of the East China Sea. ≥ 10℃ The accumulated temperature is 4500-5500℃, and rice is planted for more than one season and less than two seasons in most areas. 170- 185 days for japonica rice. The precipitation in the growing season is 700- 1300mm, and the sunshine 1300- 1500m. It is cold and rainy in spring, and early rice is easy to rot, but the temperature and light conditions are good in autumn, and the production level is still high. Rice thrips is the main pest. In the future, we should plant double-cropping rice, expand hybrid rice, work hard on super-high yield, rationally rotate crops and fertilize the soil in many ways.
Ⅱ2. Single cropping rice and double cropping rice subregion in Sichuan-Shaanxi basin. Sichuan Basin and Chuandao Plain in the south of Shaanxi are the main parts, including 194 counties (cities) in Sichuan, Shaanxi, Henan, Hubei and Gansu provinces. Accumulated temperature ≥ 10℃, safe growth period of indica rice is 156- 198 days, and that of japonica rice is 198 days. Sunshine lasts for 7000- 1000 hours. The temperature in the basin rises earlier in spring than that in the eastern two subregions, and drops faster in autumn. Spring drought has hindered the popularization of double-cropping rice, which has fallen below 3% at present, making it the region with the largest number of paddy fields in winter in China, accounting for 4 1% of paddy fields. The main crop is indica rice, and a small amount of japonica rice is distributed in mountainous areas. The main pests and diseases are rice blast and rice planthopper. In the future, we should create conditions for expanding planting.
Ⅱ3. Sub-region of double cropping rice in hilly plain of the south of the Yangtze River. Annual accumulated temperature ≥10℃ to the south of the 5300℃ line, to the north of Nanling Mountains, from the east slope of western Hunan and Hubei to the coast of the East China Sea, ***294 counties (cities). The annual accumulated temperature ≥ 10℃ is 5300-6500℃, the safe growth period of indica rice is 176-2 12 days, and that of japonica rice is 206-220 days. Double cropping rice accounts for 66% of paddy fields. The precipitation in the growing season is 900- 1500mm, and the sunshine 1200- 1400 hours. The warmth in spring and summer is good for rice growth. However, the "Meiyu" was followed by summer drought, which led to high temperature ripening of early rice and difficulty in planting late rice. Paddy fields are mainly in lakeside plains and hilly valleys. Most of the plains are planted in winter-double cropping rice, and most of the hills are planted in winter fallow fields-double cropping rice, mainly indica rice, with double cropping rice, rice blast and yellow rice borer as the main pests and diseases. The rice yield is lower than that of the other two subregions 15%. In the future, areas with conditions can develop double-cropping rice in the form of "late matching", develop low hilly red yellow soil and transform low-yield fields.
Three. Single and double cropping rice planting areas in southwest plateau. Located in Yunnan-Guizhou and Qinghai-Tibet Plateau, ***39 1 county (city). The rice area accounts for 8% of the country.
ⅲ1.One-season and double-season rice subregion in the mountainous area of Xiangxi Plateau in eastern Guizhou. Including 94 counties (cities) in central, eastern, western Hunan, southwestern Hubei and southeastern Sichuan. The climate is not clear in four seasons, and the annual accumulated temperature is ≥10℃ and 3500-5500℃. The safe growth period of indica rice is 158- 178 days, and that of japonica rice is 178- 184 days. In the growing season, the sunshine is 800- 1 100 hours, and the precipitation is 800- 1400 mm. In the north, there is often a spring drought followed by a summer drought. Most of them are single-season middle rice or late rice, and most of them are rape-rice double-season rice. Rice is distributed vertically. Japonica rice is planted at high altitude and indica rice is planted at low altitude. The main pests and diseases are rice blast and Chilo suppressalis. The self-sufficiency rate of grain is low, and 30-50% of counties rely on external adjustment for food shortage. In the future, it is still necessary to emphasize increasing rice production, which is the basis of poverty alleviation. Sichuan low-heat valley should actively develop double-cropping rice.
Ⅲ2. Single-season rice and double-season rice sub-region in ridge and valley of Yunnan-Sichuan Plateau. Covering 62 counties (cities) in northern Yunnan, southwestern Sichuan, northwestern Guangxi and central and western Guizhou/kloc-0. There are many "dams" in the area, and the vertical difference is obvious. The annual accumulated temperature ≥ 10℃ is 3500-8000℃, the safe growth period of indica rice is 158- 189 days, and that of japonica rice is 178- 187 days. In the growing season, sunshine 1 100- 1500 hours, precipitation of 530- 1000 mm, and long dry season in winter and spring limit rice multiple cropping. Broad bean (wheat)-rice is the main crop, and winter paddy field accounts for more than 1/3 of paddy field. The highest elevation of paddy field is 27 10 meter, which is also the highest limit of paddy field in the world. Most of them are cold-resistant medium japonica or early medium japonica. Rice blast and yellow rice borer are more harmful. In the future, we will actively develop double-cropping rice in the valley below1500m, and actively develop mid-season indica rice and high-quality rice mainly with hybrid rice in the valley below1200-2000m.
Ⅲ3. Single-cropping rice subregion in alpine valleys of Qinghai-Tibet Plateau. The area suitable for planting rice is very small, and rice fields are distributed in limited valleys with low altitude. Among them are rice in central Yunnan, Deqin and Mangkang and Medog counties in eastern Tibet. Due to poor production conditions, rice yield per unit area is low and unstable, but it has the potential to increase production.
The rice planting area in northern China is only 30 million mu all the year round, accounting for about 6% of the rice planting area in China. The following is just a general introduction.
Ⅳ. Single cropping rice planting areas in northern China. It is located in Qinling Mountains, north of Huaihe River, south of the Great Wall and east of Guanzhong Plain, including Beijing, Tianjin, Hebei, Shandong, Henan and parts of Shanxi, Shaanxi, Jiangsu and Anhui, with a total of 457 counties (cities). The area of rice only accounts for 3% of the whole country. This area has two sub-areas:
Ⅳ 1. Middle-early maturity subregion of the northern plain of North China, Ⅳ 2. Mid-late maturity subregion in hilly region of Huanghuai Plain. Accumulated temperature ≥ 10℃ is 3500-4500℃. The safe growth period of rice is about 130- 140 days, during which the sunshine 1200- 1600 hours, the precipitation is 400-800 mm ... It is dry in winter and spring, and the rain is concentrated in summer and autumn. In the Haihe River and Beijing-Tianjin rice areas in the north, most of them are medium-mature japonica rice in one season, and most of them are double-season wheat and rice in Huanghuai area, mostly indica rice. Rice blast and Chilo suppressalis are more harmful. In the future, it is necessary to develop water-saving rice planting techniques and implement comprehensive management of rice fields.
ⅴ. Early-maturing single-cropping rice planting areas in Northeast China. Located in the north of Liaodong Peninsula and the Great Wall, east of Daxing 'anling, including all of Heilongjiang and Kyrgyzstan, most of Liaoning and northeastern Inner Mongolia, *** 184 county (flag, city). The area of rice only accounts for 3% of the whole country.
This area has two sub-areas: ⅴ 1. Extra-early maturity subregion of Heiji Plain Valley; ⅴ 2. Early maturity subregion of Liaohe coastal plain. The accumulated temperature ≥ 10℃ is less than 3500℃, and low temperature chilling injury often occurs in northern areas. The safe growth period of rice is about 100- 120 days, during which the sunshine is 1000- 1300 hours, and the precipitation is 300-600 mm ... In recent years, rice has expanded rapidly, and the variety is early japonica rice with extra early maturity or mid-late maturity. Rice blast and rice miner are more harmful. In the future, we should speed up the construction of Sanjiang Plain, continue to expand paddy fields, improve the new technical system of rice cultivation in cold regions, and popularize water-saving rice cultivation techniques.
ⅵ. Planting area of single-season rice in northwest arid area. Located in the west of Daxing 'anling, the Great Wall, Qilian Mountain and the northern part of Qinghai-Tibet Plateau, Yinchuan Plain, Hetao Plain and the marginal areas of Tianshan North-South Basin are the main rice-growing areas, accounting for only 0.5% of the country's rice-growing area.
This area has three sub-areas: ⅵ 1. Early maturity subregion of northern Xinjiang basin; ⅵ 2. Middle-mature subregion of South Xinjiang Basin; ⅵ 3. Early-middle maturity subregion of Gansu-Ningxia-Jinmeng Plateau. The accumulated temperature ≥ 10℃ is 2000-5400℃, and the safe growth period of rice is 100- 120 days. The growth period is sunshine 1400- 1600 hours, and the precipitation is 30-350 mm ... The rice is completely irrigated, and it is basically early-middle maturity, drought-tolerant and high-yield japonica rice. Rice blast and water fly maggots are more harmful. Drought, sand and alkali are the three major obstacles, so it is necessary to implement water-saving rice planting techniques, apply more farm manure and transform low-and medium-yield fields.