资源环境科技发展态势分析平台

As the growth in global population has led to greater demands for food and energy, societies have been pressured to increase food production. Closing the gap between current and potential yields is one means of producing more food. In this study, we first identify the gaps between the potential yield and actual on-farm yield of maize for ten climate zones (CZs) in Northeast China (NEC) from 1961 to 2010. We then use trend analysis to assess yield gaps caused by suboptimal water availability (YG(w)). Finally, we identify the CZs where maize yields could be increased through improved irrigation management. Nonparametric trend analysis showed an estimated regional area-averaged yield gap of 64% between potential yield and actual on-farm yield; this gap decreased by 11.0% per decade over the study period (p < 0.01). Although yield gaps have fallen to 43% during the past decade, on-farm maize yield still accounts for only 57% of potential yield. Therefore, there is still a considerable yield gap in maize production in NEC. Simulation results indicated that the average YG(w) of 23% in NEC is due to suboptimal water availability. Moreover, in CZs with a positive water deficit, the YG(w) ranged from 14 to 48%; in the remaining CZs, the YG(w) ranged from 5 to 13%. We conclude that there are substantial opportunities to increase maize production by up to 2.8 t ha(-1) through improved irrigation management in cases where the limited irrigation resources can be improved, especially in CZs that receive less than 450 mm of precipitation during the maize-growing season.