Suitable Technological Parameters of Mulched Drip Irrigation of Corn in Northwest China：Irrigation Frequency and Drip Line Spacing

In order to explore suitable technical parameters of mulched drip irrigation in semi-arid region of northwest China，spring corn was taken as test object，Minqin county in Weiwu city was taken as typical test area，field tests from March to September in 2017 were conducted，and interaction combination effect of irrigation frequency（P1∶5 d，P2∶7 d，P3∶9 d）and drip line spacing（J1∶0.9 m，J2∶1.1 m，J3∶1.3 m）on soil water and nitrogen distribution，spring corn physiological characteristics，yield and water use efficiency were analyzed.Results showed that，when drip line spacing was the same，width of wet zone was smaller，fluctuation range of soil water and nitrogen content in each soil layer were smaller when irrigation frequency was higher，and average soil moisture content of low and medium frequency treatments at the same soil depth were higher.When irrigation frequency was the same，treatment with larger drip line spacing had more moisture to deep soil.When irrigation frequency was the same，yield and water use efficiency under smaller drip line spacing treatments were higher.When drip line spacing was the same，yield and water use efficiency under high and medium frequency were higher.Yield of P1J1 treatment was the highest，which was 16 485.25 kg/hm2，followed by P2J2 treatment yielded 16 292.21 kg/hm2，which had the highest water use efficiency，reached 3.66 kg/m3.