Does precipitation keep pace with temperature in the marginal double-cropping area of northern China?

Abstract

Northern China is the major grain-production region in the country. To adapt to climate change and ensure food security with a fixed area of arable land, utilizing a multiple cropping frequency each year is regarded as an efficient method of offsetting the projected negative yield impacts on staple crops. Given that climate warming prolongs the potential growing season and benefits the expansion of multi-cropping systems, this research investigated whether changes in precipitation will keep pace with temperature in the marginal double-cropping area of northern China under two scenarios (RCP4.5 and RCP8.5). Our results indicated that northern China will experience consistent warming, which will cause the limits of the double-cropping system to move remarkably towards the northeast and northwest in this century. However, the increased precipitation may not be sufficient to alleviate the water deficiency in the double-crop rotation and support the realisation of double-cropping benefits due to increasing heat resources. Although the potential yield will be considerable in the marginal double-cropping area after future expansion, the instability of rain-fed yields will gradually increase with the decrease in precipitation in the marginal region unless supplemental irrigation is applied. The insufficient precipitation was projected to negatively affect the potential yield in this area by 56–67 %. Moreover, the coefficient of variation of yield was great due to the large spatial distribution difference in the cumulated precipitation. After adopting limited irrigation in key wheat growth periods, this negative effect was predicted to be alleviated by approximately 10–12 %. In the entire marginal region, the northeast faces the lowest risk of precipitation deficiency during double-cropping system expansion. It was concluded that the double-cropping system is an efficient adaptation strategy worth encouraging in the context of climate change; however, this approach should be considered only after considering the local cumulative precipitation and the condition of the water supply.