Three irrigation levels and five N application rates were arranged as split plots in a randomized
complete block design with three replications. The irrigation levels were conventional irrigation (12000
m3/ha), 10% or 12.5% water-saving irrigation (10800 m3/ha in 2006 and 10500 m3/ha in 2007), and 20%
or 25% water-saving irrigation (9600 m3/ha1 in 2006 and 9000 m3/ha), these irrigation levels are
designated W1, W2, and W3, respectively.