Abstract:

This paper studies the influence of agricultural climate resources change on alfalfa production, and provides scientific basis for revealing the relationship between climate change and alfalfa production and developing targeted management measures for alfalfa production. Based on the daily average temperature, minimum temperature and precipitation data from 1960 to 2019, as well as the observation data of alfalfa growth period in 2023 and 2024 in Hohhot, the interdecadal climate change research method was used to analyze the changing laws of alfalfa re-greening period, the earliest germination period of spring sowing, the minimum temperature during overwintering period, the accumulated temperature of each crop and the irrigation water demand in different growth stages. Results indicated that over the past 6 decades, the alfalfa re-greening period and earliest spring germination date had advanced significantly by 15.5 and 19 days, respectively. Concurrently, the overwintering minimum temperature increased by 4.8℃, and accumulated temperature in growing period (≥5℃) increased by 274.9℃. The precipitation adaptation efficiency remained suboptimal (0.2-0.3) during the first two harvests, requiring substantial irrigation (100-200 mm), while improving markedly (0.7) in subsequent harvests with significantly reduced irrigation demands (30-50 mm). Climate warming advanced the re-greening period of alfalfa by 7-10 days and extended the growth period by 15-20 days. The increase of precipitation concentration led to significant spatial and temporal differences in irrigation demand, which in turn promoted the transformation of alfalfa stubbles, and the yield per unit area increased by 12%-15%. The research results can provide scientific guidance for the efficient use of climate resources and avoiding disadvantages in alfalfa production.

Key words: alfalfa, agricultural climate resources, effective production, climate change, Hohhot