Quantitative Assessment of Impacts of Climate and Economic-technical Factors on Grain Yield in Jilin Province from 1980 to 2008

Key words: 
• climate factor /
• economic-technical factor /
• contribution weight /
• grain yield

Abstract: Climate change is one of the most important challenges threatening agricultural grain yield and food security. Determining the
factors influencing grain yield in Jilin Province and the weights of their contribution are a very important task, because Jilin Province is an
important agriculture base in China. In this study, the accumulation factor sequence evaluating data method was used to analyze the
climate and economic-technical factor contribution weights to grain yield and grain yield changes in each city of Jilin Province. Climate
yield was also estimated to study the climate effect on the grain yield, and it was calculated in two ways: an improved algorithm and a
traditional quadratic method. The results show that the climate and economic-technical factors have different contribution weights to
grain yield in different cities in Jilin Province. The contribution weight of the climate factor to grain yield was 0.212–0.349, while that the
economic-technical factor was 0.651–0.788. Furthermore, the changes of the climate factor contributing to grain yield changes
accounted for 0.296–0.546, and the changes of the economic-technical factor accounted for 0.454–0.704. The weights of climate and
economic-technical factor contributing to grain yield are very different between the eastern and western cities in Jilin Province, but their
weights contributing to the grain yield change are similar in these cities. In general, the amount of fertilizer used per hectare (FUPH) is
the main factor affecting grain yields and yield changes from 1980 to 2008. It is noted that when the FUPH growth rate stabilized after
1995, the effects of the climate factor on the grain yield become more obvious than before. The improved algorithm is effective for
estimating climate yield in Jilin Province, and the climate yields were mostly between –500 kg/ha and 500 kg/ha, and showed a slightly
rising trend in most cities.