Abstract:

Based on the observation data of 12 national weather stations in Xianyang City in the winter of 2020/2021 (from December to February of the following year), and compared with the climatic standard values of winter from 1959 to 2019, the agrometeorological conditions in the winter of 2020/2021 in Xianyang and their impact on major crops and facility agriculture were analyzed. The results showed that the winter temperature in 2020/2021 was relatively high, the negative accumulated temperature in the north was insufficient, the precipitation was more, and the sunshine was less. During the winter, there were large-scale low-temperature cold waves, few sunshine and other agricultural meteorological disasters. The average temperature, the daily maximum temperature and the daily maximum precipitation broke through or were close to the historical extreme values. Generally speaking, the meteorological conditions in the winter of 2020/2021 had more harm than good to agricultural production. (1) The high temperature was conducive to the increase of tillering of winter wheat, but the wheat could not get cold hardening and was prone to freezing damage. (2) The lack of negative accumulated temperature in the north made winter wheat and rapeseed be more sensitive to the low temperature in spring, delayed the dormancy period of fruit trees and reduced the fruit setting rate of apple trees. (3) Less sunlight and more cloudy and overcast days caused low temperature in greenhouses and slowed the growth of greenhouse vegetables which had falling flowers and fruits. In cold wave weather, freezing injury could easily affect the yield and quality of vegetables. (4) At the same time, cold wave weather in winter was beneficial to killing insect eggs and reducing pests and diseases. (5) The first through-moisture rain in late February increased soil moisture and laid a good foundation for agricultural production in spring.

Key words: the winter of 2020/2021, meteorological conditions, agricultural production, Xianyang