Abstract:

In order to study the impact of climate change on the growth and development of spring barley in Xigazê, meteorological data of the spring barley growth season (April September) in Xigazê from 1992 to 2022 and station observation data during the spring barley development period were used. Statistical methods, univariate linear regression, correlation analysis, and M-K test were used to analyze the interannual variation characteristics of temperature, precipitation, and sunshine hours during the growth period of spring barley in Xigazê, as well as the influence of meteorological factors on the growth and development period of spring barley. The results showed: (1) In the past 31 years, the annual temperature during the growing season of spring barley in Xigazê has been increasing year by year, with an average increase of 0.57 ℃ every 10 years, which is more significant than the local annual average temperature; the average annual precipitation during the growing season was 422.8 mm and the average annual precipitation is 430.6 mm, both showing a weak downward trend. The main precipitation is concentrated in the growing season of spring barley, accounting for more than 90% of the total annual precipitation, which is conducive to meeting the water demand of barley during the key development period; the average sunshine hours during the growing season are 1560.4 hours, showing a weak decreasing trend year by year, with an average decrease of 15.8 hours every 10 years, which did not pass the extreme significance test. (2) The average growth period of spring barley in Xigazê is 118 days, and it shows a decreasing trend year by year, with an average decrease of 3.99 days every 10 years. A shortened growth period represents an accelerated development process and has a certain impact on yield and quality; (3) the decrease in the number of days during the entire growth period of spring barley is mainly caused by four growth periods. The growth period days from emergence to three leaf stage, jointing to booting stage, booting to heading stage, and flowering to milk maturity stage show a trend of extension, with extension rates of 0.11 d/10a, 1.58 d/10a, 0.73 d/10a, 5.33 d/10a, respectively. Among them, the extension days from emergence to three leaf stage are the least significant; than, the decrease in the number of days during the entire growth period of spring barley is mainly caused by five growth periods. The number of days in the growth period from sowing to emergence, from three leaves to tillering, from tillering to jointing, from heading to flowering, and from milk maturity to maturity showed a decreasing trend, with shortening rates of 0.73 d/10a, 2.60 d/10a, 1.53 d/10a, 1.06 d/10a, 7.22 d/10a, respectively. The shortening rate was the highest from the milk-ripe stage to the maturity stage, followed by that from the three-leaf stage to the tillering stage., followed by the milk maturity stage; Shortening the length of the growth period is not conducive to yield formation, especially during the milk ripening maturity period, which can lead to insufficient grain filling and withered grains, thereby affecting yield and quality. The research results can provide decision-making basis for local government departments and scientific basis for the future sustainable development of characteristic agriculture and food security in Xizang Plateau.

Key words: climate change, spring barley, growing season, Xigazê, Mann-Kendall test, impact