Decomposition of the Factors Determining Changes in China’s Maize Yields

Abstract

China’s maize productivity and fertilizer consumption both have significant impact on global markets, and must be clarified through macro-level studies of Chinese maize yields. As such, this study used a crop response model to estimate the effects of fertilizer nutrients, seed input per unit area, and climate factors on maize yield. The results suggest that phosphorus and potassium inputs significantly affect maize yield, especially in major maize-producing areas. This study also confirmed the relationship between lower seed input per unit area and a higher yield. Discipline: Agricultural economics/Crop production Additional key words: crop response model, decomposition analysis *Corresponding author: e-mail kusano11@affrc.go.jp Recieved 19 September 2014; accepted 2 June 2015. 10_Kusano_p063-071.indd 63 2015/11/26 21:15:26 64 JARQ 50 (1) 2016 E. Kusano et al. nitrogen, phosphorus, and potassium inputs in maize production are calculated using both numeric data and information in policy documents. Then, temperature, precipitation, and sunshine hours during a specific period when these factors are thought to affect maize productivity are estimated based on daily climate data and annual seeding days. The effects of these factors on maize productivity are then estimated through regression analysis. Finally, these effects are expressed in terms of how much each factor contributes to changes in maize yield.