Abstract:

To study the effects of rainfall, average temperature and sunshine hours on forage yield and the quantitative relationship among them, according to the monthly meteorological data, the rainfall, average temperature and sunshine hours were divided into 13 groups based on the time period from 2012 to 2019, and correlation analysis and multiple regression analysis were conducted on rainfall, average temperature, sunshine hours and fresh grass yield of natural grassland. The results showed that: the correlation between rainfall and fresh grass yield was the highest, the positive correlation between the total rainfall and fresh grass yield reached a very significant level from March to July (correlation coefficient r=0.839, P=0.009<0.01), and rainfall had the greatest impact on forage yield in March and April. The positive correlation between average temperature and fresh grass yield reached a very significant level from February to July (correlation coefficient r=0.840, P=0.009<0.01), and the average temperature had the greatest impact on forage yield in February. There was no significant correlation between sunshine hours and fresh grass yield (P>0.05). Multiple regression analysis showed that, fresh grass yield increased by 289.693 kg/hm² with every 1 mm increase in the total rainfall from March to July, and by 144.93 kg/hm² with every 0.1℃ increase in the average temperature from February to July. The effect of rainfall on fresh grass yield was greater than that of average temperature.

Key words: natural grassland, fresh grass yield, rainfall, average temperature, sunshine hours