What are the natural conditions for grape cultivation in China?

Although grapes are not critical of climate, soil and other natural conditions, in order to obtain high quality and high yield, and obtain the best economic benefits, we must choose the most suitable cultivation area according to the ecological characteristics of grapes, so as to adjust measures to local conditions and give full play to the natural advantages of the region.

First of all, as far as climatic conditions are concerned, grape is a kind of warm-loving fruit tree, which has a good temperate climate and poor cold tolerance. Growth begins when the temperature is 1℃, and the temperature above 18℃ is appropriate for the whole growth period. However, different developmental stages require different suitable temperatures. The germination period is 1-12℃, the new shoot growth and flower bud differentiation period is 28-32℃, and the flowering period is 25-3%. If the temperature is lower than 15℃, pollination and fertilization will be affected. When the berries ripen from July to September, the temperature should be above 24℃, and if it is below 15℃, the fruits will not be fully matured. The cold tolerance of grapes also varies with different parts of the plant. Among them, the root system is the least tolerant to low temperature. When the temperature drops to-5--7℃, there is a danger of freezing to death. Therefore, it is generally difficult for grapes to survive the winter in North China and Northeast China. However, since ancient times, the working people in our country have created a cold-proof method of burying vines in pits, so that grapes can safely overwinter at -2℃. It can be seen that only from the point of view of temperature, except the northern part of Heilongjiang and the Qinghai-Tibet Plateau, which are extremely north in geographical location, are not suitable for grape growth and development because of the low temperature, and the rest areas are suitable for grape cultivation.

Another ecological feature of grapes is that they prefer to be dry and avoid being wet. Under sufficient illumination, Ye Yuan is dark in color, strong in assimilation, high in sugar content, strong in taste and high in yield. If the light is insufficient, the opposite is true. In the vast area south of the Yangtze River in China, although the temperature is high during the grape growing season, due to excessive humidity, there are not only many diseases, but also affect the development and growth of grapes, resulting in overgrowth of branches and vines and poor results. Especially in the Yangtze River valley, the rainy weather in early summer every year is continuous, which not only hinders the fertilization of flowers and fruits, but also spreads diseases, which has a great influence on the growth and fruit of grapes. In most parts of North China and Northwest China, during the grape growing season, the climate is dry and sunny, with an average annual sunshine of more than 2,5 hours. The climate is very conducive to the growth and development of grapes and the product quality is good. Therefore, from the light, heat, water and humidity conditions, the natural conditions of grape cultivation in North China and Northwest China are far better than those in South China, which is a good place to establish and develop grape commodity production bases in China. However, it is worth noting that the annual rainfall here is less, ranging from 5-6 mm to 5-1 mm, which is still far from the requirement of 6-8 mm for grape growth. In addition, the uneven distribution of rainfall in seasons causes drought in spring and insufficient water in the soil, which is not conducive to the early growth of grapes, so irrigation must be carried out in time. Especially in the arid northwest region with scarce rainfall, the layout of vineyards should be chosen in places with sufficient water resources and irrigation facilities. Putaogou in Turpan, Xinjiang is an example. The reason why it can grow in this hot and dry place with an annual rainfall of only 5 mm lies in that there is a valley with a length of more than ten miles and a width of more than one mile, named Grape Valley, in which there are 484 springs, which moisten and irrigate the grapes on both sides of the valley to ensure its vigorous growth and high yield.

Secondly, from the perspective of soil conditions, grapes have the characteristics of barren resistance and wide adaptability to soil. Whether in alluvial soil with deep soil layer, barren sandy loam or gravelly loam, or saline-alkali soil, the grape can grow. This is of great significance to the development and utilization of large areas of sandy wasteland and barren hills in northwest and north China, the development of grape production and the rational use of land resources. Since liberation, our country has created many successful experiences in this respect. For example, Xiaoxian County, Dangshan County, Anhui Province, and Zhengding County, Hebei Province, used the sandy wasteland of the old riverbed to build vineyards and create high yields. Changli County, Hebei Province, on the other hand, cultivated mountains and hills, planted grapes on gravel soil with thin soil layer and many stones, and developed production. Dunhuang in Gansu and Nuomuhong Farm in Qinghai, which are located on the edge of desert and Gobi, make full use of the soil and climate conditions of Gobi to develop Turpan grapes and bear rich fruits. To sum up, at present, the soil types in China's grape producing areas are diverse, and the area of land resources suitable for development is vast.

according to the requirements of wine or raw grapes on environmental conditions, the whole country can be roughly divided into the most suitable area, sub-suitable area and unsuitable area (Figure 2-2): ① The most suitable area: mainly distributed in the Yellow River and Yangtze River basins, with its northern boundary starting from Dalian in the east, passing through Changli, Hebei-Tangshan-Baoding-Jiexiu, Shanxi-Lanzhou, Shaanxi to Minhe-Xining in winter, which is roughly equal to the absolute minimum temperature of 21. The southern boundary is located in the north of Shanghai-Hangzhou-Tongling-Huoshan-Suixian-Fangxian-Wanyuan-Marcand. In this area, not only do grapes not need to be covered in winter, but all kinds of ecological conditions are very suitable for the growth and development of European grapes, and high yield and high quality can be obtained. Moreover, because there is no need to cover, a lot of manpower and material resources can be saved, and the best economic benefits can be obtained with less investment. It is a treasure land for developing grape production in China. ② Sub-optimum area: mainly distributed in the north and south sides of the optimum area, between the optimum area and the unsuitable area. Its northern boundary is Tonghua, Jilin to the west, and it passes through Kaiyuan, Liaoning-Chifeng, Inner Mongolia-Weichang, Hebei-Datong, Shanxi-Shenmu, Shaanxi-Shizuishan, Ningxia-Zhangye, Gansu-Jiuquan to the south. The absolute minimum temperature in winter here is -25-3℃, so it is expensive to cultivate grapes for cold protection, which requires a lot of labor and costs. Generally, only early-maturing varieties of European species can be planted. The southern boundary of the southern sub-optimal zone is generally located in the north of Wenzhou-Jianyang-Suichuan-Xintian-Quanzhou-Dushan-Kunming-Bijiang line. The temperature in this area is high, and there is a lot of rainfall, especially in April-June, which is prone to diseases, so it is necessary to choose varieties with strong disease resistance. ③ Inappropriate area: it is distributed in the north and south of the sub-suitable area. Because the ecological conditions are not suitable for the cultivation of general varieties, special measures should be taken or special varieties should be selected before planting.

Figure 2-2 Schematic diagram of the most suitable area, sub-suitable area and unsuitable area of grapes

As for the most suitable areas for drying grape varieties, they are mainly Turpan, Shanshan, Toksun, Hotan in Xinjiang, and Dunhuang in Gansu. In these places, during the grape growing season, the accumulated temperature is high, the annual precipitation is low, the climate is dry, and the sunshine is sufficient, which is very beneficial to the natural temperature drying.