How are wheat-growing regions divided? A detailed explanation of growing conditions in China's various production areas

Wheat is widely distributed in China and is grown throughout the country. Because natural conditions vary from place to place, distinctly different growing regions have formed. As early as 1936, China's wheat was divided into 7 regions based on climate and wheat production conditions, of which 6 were winter wheat regions and 1 was a spring wheat region; in 1937, based on the results of 3-year regional adaptability trials of more than 100 wheat varieties at 9 sites in 8 provinces, the 6 winter wheat regions were grouped into 3 main regions. This was the earliest research on wheat regionalization in China.

In 1943, based on the winter or spring habit of Chinese wheat, grain color, and hardness or softness of texture, the main wheat regions nationwide were divided into 3 growing regions: the hard red spring wheat region, the mixed hard winter and spring wheat region, and the soft red winter wheat region. In the early 1960s, "Wheat Cultivation in China" again divided the country's wheat into 3 main regions - the northern winter wheat region, the southern winter wheat region, and the spring wheat region - and 10 subregions, laying the foundation for a relatively complete wheat regionalization in China. In particular, the boundary line between winter and spring wheat and the division of each main wheat region were redefined. Later, scientists in meteorology, varieties, cultivation, and other disciplines successively proposed different regionalizations according to the characteristics of their respective disciplines. Based on the regionalization in "Wheat Cultivation in China," the book "Wheat Varieties and Their Pedigrees in China" directly divided the country into 10 wheat regions, and some regions were further divided into several subregions.

Since the 1980s, wheat production nationwide has developed rapidly, relevant materials on wheat regionalization have been continuously enriched, and understanding has also continued to deepen. For this reason, on the basis of the original 10 wheat regions - Northeast spring wheat, Northern spring wheat, Northwest spring wheat, ** winter-spring wheat, Qinghai-Tibet spring-winter wheat, Northern winter wheat, Huang-Huai winter wheat, Middle and Lower Yangtze winter wheat, Southwest winter wheat, and South China winter wheat - corresponding revisions and adjustments were focused on the scope of each region and the direction of regional boundaries. Based on the different natural conditions and wheat cultivation characteristics across China, the country is divided into different types of wheat-growing regions, making it easier to adapt to local conditions and rationally arrange wheat production.

1. Northeast spring wheat region

The Northeast spring wheat region includes all of Heilongjiang and Jilin provinces, most of Liaoning Province except the southern coastal area, and the northeastern part of the Inner Mongolia Autonomous Region. The wheat area and total output of the whole region are each close to about 8% of the national total, and account for about 47% and 50% of the national spring wheat area and total output, so it is a major spring wheat production area, with Heilongjiang Province predominant.

The Northeast spring wheat region is high in the northwest and low in the southeast; elevation in most areas is 40-500 m, and in parts of Inner Mongolia in the northwest it can reach 600-800 m. The soil is mainly chernozem, with deep soil layers and fertile texture. In the Sanjiang Plain of eastern Heilongjiang and the Heihe area of northern Heilongjiang, wheat area is relatively concentrated, and large numbers of state farms have been established there; their wheat output accounts for about 1/2 of the total spring wheat output of the entire Heilongjiang Province. The whole region has a continental climate, with low temperatures and insufficient heat, and extremely large differences between winter and summer temperatures. Temperature increases from north to south; the average temperature in the coldest month is -23 to 10°C, and the absolute minimum temperature is -41 to 27°C, making it the lowest-temperature region in the country. Annual precipitation is 320-870 mm, and precipitation during the wheat growing period is 130-333 mm, but the east is rainy and the west is dry. In the Sanjiang Plain of eastern Heilongjiang, excessive rain in the later period often causes waterlogging disasters and affects harvest. In contrast, areas such as Baicheng in Jilin Province and Chaoyang in Liaoning Province in the west often suffer from drought and wind-sand damage because of spring drought and frequent winds. Wheat varieties in this region are spring type, sensitive to light response, and have a short growing period, mostly around 90 days. Diseases are mainly root rot, rust, and scab, while rosette dwarf virus disease and take-all also occur. The cropping system is one crop per year, with sowing in mid-April and maturity around July 20. In the whole region, in addition to timely control of various diseases, draining water and preventing dampness in the east; controlling weeds in the north; and building water conservancy in the west, adopting cultivation techniques such as less deep plowing, more deep loosening, and reduced tillage or no-till to prevent wind, fix sand, and reduce evaporation are all main measures for increasing wheat yield. According to the distribution of temperature and precipitation, this region can also be divided into 3 subregions: northern high-cold, eastern humid, and western arid.

2. Northern spring wheat region

The Northern spring wheat region lies west of the Greater Khingan Mountains, north of the Great Wall, and extends west to the Yikezhao League and Bayannur League of the Inner Mongolia Autonomous Region, bordering the People's Republic of Mongolia to the north. The region is dominated by the Inner Mongolia Autonomous Region and also includes the areas north of the Great Wall in Hebei and Shaanxi provinces and northern Shanxi Province. The wheat planting area and total output of the whole region account for about 3% and 1% of the national totals respectively, and about 20% of the region's grain crop area. The average wheat yield per unit area is the lowest among all wheat regions in the country, and development is very uneven; yield levels are relatively high in the Yikezhao League and Bayannur League of the western Hetao Irrigation District, while Zhangjiakou in Hebei Province, Yanbei in Shanxi Province, and Yulin in Shaanxi Province are all low-yield areas.

The elevation of the whole region is 1000-1400 m, and the soil is mainly chestnut soil. The continental climate is markedly characterized by cold, little rain, poor soil, and poor natural conditions. The average temperature in the coldest month is -17 to 11°C, and the absolute minimum temperature is -38 to 27°C. Annual precipitation is 309-496 mm, with most areas around 300 mm, and precipitation during the wheat growing period is only 94-168 mm. The cropping system is mainly one crop per year, with a few areas having three crops in two years. Wheat varieties in this region are spring type, sensitive to light response, and have a growing period of 90-120 days. The sowing period is from mid-March to mid-April, and maturity is around early July, at the latest up to the end of August. The main diseases in the whole region are leaf rust, stem rust, yellow dwarf disease, and rosette dwarf virus disease; insect pests are mainly wheat stem maggot and armyworm. Early-spring drought, forced ripening by high temperatures in the later period, damage from dry hot winds, and soil salinization in the Hetao Irrigation District are all major problems in wheat production. For yield-increasing measures, cropping systems such as fallow rotation should be implemented to improve soil fertility; in irrigation districts, furrow and border irrigation should be promoted, canal system support should be improved, the irrigation system should be improved, and soil salinization should be prevented. According to differences in precipitation between the north and south of the whole region, it can be divided into two subregions: northern arid and southern semi-arid.

3. Northwest spring wheat region

The Northwest spring wheat region is dominated by Gansu Province and the Ningxia Hui Autonomous Region, and also includes western Inner Mongolia Autonomous Region and parts of eastern Qinghai Province. Wheat fields account for about 4% of the national total, and total output reaches about 5%. Yield per unit area is second only to the Middle and Lower Yangtze winter wheat region nationwide, and ranks first among all spring wheat regions; there are large differences among areas, with relatively high yields in the Hexi Corridor irrigation district of Gansu Province and the Ningxia-Yinchuan Yellow River irrigation district.