Water deficit and N fertilizer are the two primary limiting factors for wheat yield in the North China plain, the most
important winter wheat (
Triticum aestivum
L.) production area in China. Analyzing the yield gap between the potential
yield and the attainable yield can quantify the potential for increasing wheat production and exploring the limiting factors
to yield gap in the high-yielding farming region of North China Plain. The Decision Support System for Agrotechnology
Transfer (DSSAT) model was used to identify methods to increase the grain yield and decrease the gap. In order to explore
the impact of N and cultivars on wheat yield in the different drought types, the climate conditions during 1981 to 2011
growing seasons was categorized into low, moderate, and severe water deficit classes according to the anomaly percentage
of the water deficit rate during the entire wheat growing season. There are differences (P < 0.0001) in the variations of the
potential yields among three cultivars over 30 yr. For all three water deficit types, the more recent cultivars Jimai22 and
Shijiazhuang8 had higher yields compared to the older ‘Jinan17’. As the N fertilizer rate increased, the yield gap decreased
more substantially during the low water deficit years because of the significant increase in attainable yield. Overall, the
yield gaps were smaller with less water stress. Replacement of cultivars and appropriate N fertilizer application based on
the forecasted drought types can narrow the yield gap effectively.
