Characteristics of water consumption in water-saving winter wheat and effects on the utilization of subsequent summer rainfall in the North China Plain

Winter wheat (Triticum aestivum L.) grows in dry season but summer maize (Zea mays L.) coincides with rainfall in the North China Plain (NCP). Increasing rainfall use efficiency and harmonizing its utilization between the two species is an effective way to mitigate impact on groundwater deriving from wheat irrigation. One to four times water supply (W1, to W4) were employed in wheat, three water treatments (W1, W2, and W4) in 2007-2008 and four (W1, W2, W3, and W4) in 2008-2009 were established in the field condition, the characteristics of water consumption in wheat and effects on rainfall utilization during subsequent maize were studied. The maximum wheat grain yield and the maximum water use efficiency were observed on the limited water treatment W2. Wheat consumed water mainly came from irrigation and precipitation on excessive water treatments. Limited water supply enhanced water consumption from soil and vacated more water storage space. Compared with W4, the vacated water storage space increased 103-116 mm (W2) and 162-168 mm (W1). The difference of soil water content derived from previous wheat disappeared (P>0.05) around at maize elongation stage because of subsequent summer rainfall, and the rainfall stored in 2 m soil body increased more 83-88 mm (W1), and 69 mm (W2) than the treatment of W4, respectively. Drainage from 2 m soil profile on excessive water treatments (55-61 mm on W4, 9 mm on W3 during wheat growth period, and 36-40 mm on W4, 18 mm on W3 from wheat harvest to maize elongation) was determined but not on limited water treatments. These results indicate that the limited irrigation would be an effective practice for water-saving and high-yielding production of wheat in the NCP.