In October, the poor surface soil moisture in most of the northern wheat areas is disadvantageous to wheat sowing.

Since September, the temperature in most of the northern winter wheat area is slightly higher, the light is sufficient, and the maturity period of autumn harvest crops is close to the same period of the year or early. At present, the deep soil moisture in most of the northern winter wheat area is good, which lays a good foundation for winter wheat sowing and emergence. However, in the past 10 days, the precipitation in most parts of North China and Huang-Huai is less than 50%, and the soil moisture in 10 cm decreases rapidly. At present, the surface soil moisture in most of the wheat area is poor, which is disadvantageous to wheat sowing. It is expected that in October, the temperature in most of the northern winter wheat area is on the high side, which is conducive to the sowing and emergence of winter wheat, but the precipitation in most areas is less than that in the western part of North China and the northeast of Northwest China, and the soil moisture will continue to decline, which is not conducive to the sowing and emergence of wheat. It is suggested that all localities should seize the fine weather to harvest stubble in time and prepare the land for ploughing; during the suitable sowing period of winter wheat, according to the changes of weather and soil moisture, try to seize the opportunity of precipitation and sow winter wheat; the wheat areas with continuous low precipitation should do a good job of drought resistance and autumn sowing in advance.

1. The maturity of most autumn harvest crops in the northern winter wheat area is a little earlier, and the stubble can be removed at the right time.

Since September, the temperature in the northern winter wheat region is close to year-round, the light is sufficient, and many obvious precipitation processes have occurred in North China and the eastern part of Northwest China, and the meteorological conditions are conducive to the full filling and ripening of autumn harvest crops. At present, the main previous crops in the northern wheat region, such as spring corn, summer corn and soybean, are in the mature harvest period, the crop development period in most areas is close to the perennial or early, and the harvest progress is close to the perennial slightly slow, but the stubble can be completed before the suitable sowing date of winter wheat.

Second, most of the deep soil moisture in the northern winter wheat area is better, but the surface soil moisture has decreased rapidly recently.

In August, the precipitation in most of the northern winter wheat region was 50mm, while that in central Hebei, central-eastern Shandong and central Henan was 100mm-250mm, and most of the farmland soil moisture was sufficient. Since September, the precipitation in the eastern part of Northwest China and the central and northern part of North China has been 50 mm, which is more than that in the same period of normal year, which further replenishes the soil moisture in farmland and lays a good soil moisture foundation for wheat sowing. However, most of the precipitation in Huang-Huai is less than 25 mm, which is 30-80% less than that in normal years, especially in the past 10 days, the precipitation in Huang-Huai and the south of North China is less than 10 mm, and the soil moisture in 10 cm has decreased rapidly, and most of the surface moisture deviation at present.

The results of soil moisture measurement on September 30 showed that the soil moisture of 20cm to 50cm in most of the northern winter wheat area was better, which provided better soil moisture for sowing and emergence of winter wheat, but the area of soil moisture deficiency of 10cm was larger. The deviation of surface soil moisture in some areas such as north-central Shaanxi, southern Shanxi, northern and eastern Henan, southern Hebei, southwestern Shandong, Peninsula and northern Anhui is disadvantageous to winter wheat sowing and emergence. Soil moisture in 2015 deviated from that in 2014 and worse than in 2013.

In March, in most of the northern winter wheat areas, the temperature is on the high side and the soil moisture decreases, which is not conducive to wheat sowing.

The temperature is expected to be on the high side in October, which is conducive to autumn harvest and stubble preparation. At present, winter wheat has been sown in Xinjiang, Gansu, Shaanxi and Shanxi. It is estimated that in October, the temperature in most parts of the northern winter wheat region is higher than that in the same period of the normal year, in which the western part of North China, the northwest of Huang-Huai and the eastern part of Northwest China are 1 / 2 ℃ higher, with good heat conditions and sunny weather, which is beneficial to autumn harvest and stubble preparation.

During the period of wheat sowing, the surface soil moisture in most of the northern winter wheat area is poor, which is not conducive to the sowing and emergence of winter wheat. It is expected that the precipitation in the northern winter wheat area in October is less than that in the same period of the normal year. The precipitation in October in the western part of North China, the northeast of Northwest China and the northwest of Huang-Huai is 10% less than that of the same period of the normal year. The soil moisture in the northern winter wheat area may continue to decline, and the range of soil moisture deviation will be expanded, which is disadvantageous to the sowing and emergence of winter wheat.

According to the changes of weather and soil moisture, northern winter wheat should take advantage of the suitable sowing time to sow seeds. According to the comprehensive analysis of the factors such as stubble of autumn harvest crops, soil moisture, future weather and climate trend, it is expected that the suitable sowing date of winter wheat in northern China this year is mainly in the first and middle of October. Among them, the suitable sowing time in Northwest China, most of North China and the north of Huang-Huai River is from late September to early October, and sowing in the southeast of Northwest China and the south of Huang-Huai River in mid-October. The temperature in the northern winter wheat area is expected to be on the high side in October. In order to avoid wheat growing before winter, various localities can seize the opportunity of future precipitation to improve soil moisture and sow seeds according to the actual situation of local production during the suitable sowing period.

IV. Suggestions on Agricultural production

First, the northern winter wheat area should seize the fine weather to harvest mature crops in time, timely stubble preparation, and make preparations for wheat sowing.

Second, in October, most of the northern winter wheat areas have high temperature and little rain, so all localities should do a good job in preserving soil moisture and resisting drought; especially in areas with deviated soil moisture, we should seize the opportunity of precipitation to sow seeds or sow seeds in time to ensure smooth sowing and emergence of winter wheat.